CALIFORNIA BUILDING CODE — MATRIX ADOPTION TABLE
CHAPTER 16A — STRUCTURAL DESIGN
CHAPTER 16A — STRUCTURAL DESIGN
| Adopting agency | BSC | BSC-
CG
|
SFM | HCD | DSA | OSHPD | BSCC | DPH | AGR | DWR | CEC | CA | SL | SLC | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 1/AC | AC | SS | SS/CC | 1 | 1R | 2 | 3 | 4 | 5 | ||||||||||||
| Adopt entire chapter | X | X | X | ||||||||||||||||||||
| Adopt entire chapter
as amended (amended
sections listed below) |
|||||||||||||||||||||||
| Adopt only those sections
that are listed below
|
X | X | X | ||||||||||||||||||||
| Chapter / Section | |||||||||||||||||||||||
| 1607A.9.2 | X | ||||||||||||||||||||||
| 1617A.1.18 | X | X | |||||||||||||||||||||
The state agency does not adopt sections identified with the following symbol: †
The Office of the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
The provisions of this chapter shall govern the structural design of buildings, structures and portions thereof regulated by this code.
The scope of application of Chapter 16A is as follows:
- Structures regulated by the Division of the State Architect-Structural Safety (DSA-SS), which include those applications listed in Section 1.9.2.1. These applications include public elementary and secondary schools, community colleges and state-owned or state-leased essential services buildings.
- Applications listed in Sections 1.10.1 and 1.10.4, regulated by the Office of Statewide Health Planning and Development (OSHPD). These applications include hospitals and correctional treatment centers.
DSA-SS and OSHPD adopt this chapter and all amendments.
Exception: Amendments adopted by only one agency appear in this chapter preceded with the appropriate acronym of the adopting agency, as follows:
- Division of the State Architect-Structural Safety:[DSA-SS] — For applications listed in Section 1.9.2.1.
- Office of Statewide Health Planning and Development:[OSHPD 1] — For applications listed in Section 1.10.1.[OSHPD 4] — For applications listed in Section 1.10.4.
In addition to the requirements of the California Administrative Code and the California Building Code, any aspect of project design, construction, quality assurance or quality control programs for which this code requires approval by the Registered Design Professional (RDP), are also subject to approval by the enforcement agency.
The following notations are used in this chapter:
| D | = | Dead load. |
| Di | = | Weight of ice in accordance with Chapter 10 of ASCE 7. |
| E | = | Combined effect of horizontal and vertical earthquake induced forces as defined in Section 12.4 of ASCE 7. |
| F | = | Load due to fluids with well-defined pressures and maximum heights. |
| Fa | = | Flood load in accordance with Chapter 5 of ASCE 7. |
| H | = | Load due to lateral earth pressures, ground water pressure or pressure of bulk materials. |
| L | = | Live load. |
| Lr | = | Roof live load. |
| R | = | Rain load. |
| S | = | Snow load. |
| T | = | Cumulative effects of self-straining load forces and effects. |
| Vasd | = | Allowable stress design wind speed, miles per hour (mph) (km/hr) where applicable. |
| V | = | Basic design wind speeds, miles per hour (mph) (km/hr) determined from Figures 1609A.3(1) through 1609A.3(12) or ASCE 7. |
| W | = | Load due to wind pressure. |
| Wi | = | Wind-on-ice in accordance with Chapter 10 of ASCE 7. |
Construction documents shall show the size, section and relative locations of structural members with floor levels, column centers and offsets dimensioned. The design loads and other information pertinent to the structural design required by Sections 1603A.1.1 through 1603A.1.10 shall be indicated on the construction documents.
Exception: Construction documents for buildings constructed in accordance with the conventional light-frame construction provisions of Section 2308 shall indicate the following structural design information:
- Floor and roof dead and live loads.
- Ground snow load, pg.
- Basic design wind speed, V, miles per hour (mph) (km/hr) and allowable stress design wind speed, Vasd, as determined in accordance with Section 1609A.3.1 and wind exposure.
- Seismic design category and site class.
- Flood design data, if located in flood hazard areas established in Section 1612A.3.
- Design load-bearing values of soils.
- Rain load data.
[DSA-SS] Additional requirements are included in Section 4-210 and 4-317 of the California Administrative Code (Part 1, Title 24, C.C.R).
[OSHPD 1] Additional requirements are included in Section 7-115 and 7-125 of the California Administrative Code.
The following information related to wind loads shall be shown, regardless of whether wind loads govern the design of the lateral force-resisting system of the structure:
- Basic design wind speed, V, miles per hour and allowable stress design wind speed, Vasd, as determined in accordance with Section 1609A.3.1.
- Risk category.
- Wind exposure. Applicable wind direction if more than one wind exposure is utilized.
- Applicable internal pressure coefficient.
- Design wind pressures and their applicable zones with dimensions to be used for exterior component and cladding materials not specifically designed by the registered design professional responsible for the design of the structure, pounds per square foot (kN/m2).
The following information related to seismic loads shall be shown, regardless of whether seismic loads govern the design of the lateral force-resisting system of the structure:
- Risk category.
- Seismic importance factor, Ie.
- Mapped spectral response acceleration parameters, SS and S1.
- Site class.
- Design spectral response acceleration parameters, SDS and SD1.
- Seismic design category.
- Basic seismic force-resisting system(s).
- Design base shear(s).
- Seismic response coefficient(s), CS.
- Response modification coefficient(s), R.
- Analysis procedure used.
- Applicable horizontal structural irregularities.
- Applicable vertical structural irregularities.
- Location of base as defined in ASCE 7, Section 11.2.
Connections that resist design seismic forces shall be designed and detailed on the design drawings.
The design load-bearing values of soils shall be shown on the construction documents.
For buildings located in whole or in part in flood hazard areas as established in Section 1612A.3, the documentation pertaining to design, if required in Section 1612A.4, shall be included and the following information, referenced to the datum on the community's Flood Insurance Rate Map (FIRM), shall be shown, regardless of whether flood loads govern the design of the building:
- Flood design class assigned according to ASCE 24.
- In flood hazard areas other than coastal high hazard areas or coastal A zones, the elevation of the proposed lowest floor, including the basement.
- In flood hazard areas other than coastal high hazard areas or coastal A zones, the elevation to which any nonresidential building will be dry floodproofed.
- In coastal high hazard areas and coastal A zones, the proposed elevation of the bottom of the lowest horizontal structural member of the lowest floor, including the basement.
The dead load of rooftop-mounted photovoltaic panel systems, including rack support systems, shall be indicated on the construction documents.
Rain intensity, i (in/hr) (cm/hr), shall be shown regardless of whether rain loads govern the design.
Where unusual erection or construction procedures are considered essential by the Registered Design Professional (RDP) in order to accomplish the intent of the design or influence the construction, such procedure shall be indicated on the construction documents.
Geotechnical and geohazard reports for review by the enforcement agency shall be accompanied by a description of the project prepared by the registered design professional (RDP) in responsible charge, which shall include the following:
- Type of service such as general acute care facility, central utility plants, K-12 school, community college, essential services, etc.
- Construction materials used for the project such as steel, concrete. masonry, wood, etc.
- Type of construction project such as new, addition, alteration, repair, etc.
- For existing buildings, extent of construction such as incidental, minor, major and/or voluntary seismic improvements as defined in Section 318, Part 10, Title 24, CCR [DSA-SS] Section 202 and California Existing Building Code Section 202A [OSHPD 1].
- Seismic force resisting system used for each structure in the project.
- Foundation system that will be used for each structure in the project such as spread footing, drilled piers, etc.
- Analysis procedure used and basis of design such as ASCE 7 Equivalent Lateral Force Procedure, ASCE 41 Nonlinear Dynamic Procedure, etc.
- Building characteristics such as number of stories above and below grade, foot print area at grade, grade slope on site, etc.
- Special features such as requirement for shoring, underpinning, retaining walls, etc.
The application for the approval of construction documents that involves structural elements or components shall be accompanied by complete and accurate structural design computations, which shall comply with requirements prescribed by the enforcement agency:
- The computations shall be preceded by a detailed index.
- The computations including each major subsection shall be prefaced by a statement clearly and concisely outlining the basis for the structural design and indicating the manner in which the structure will resist the vertical loads and lateral forces.
- The computations shall be sufficiently complete to the extent that calculations for the individual structural members and connections can be readily interpreted.
Building, structures and parts thereof shall be designed and constructed in accordance with strength design, load and resistance factor design, allowable stress design, empirical design or conventional construction methods, as permitted by the applicable material chapters and referenced standards.
Buildings and other structures, and parts thereof, shall be designed and constructed to support safely the factored loads in load combinations defined in this code without exceeding the appropriate strength limit states for the materials of construction. Alternatively, buildings and other structures, and parts thereof, shall be designed and constructed to support safely the nominal loads in load combinations defined in this code without exceeding the appropriate specified allowable stresses for the materials of construction.
Loads and forces for occupancies or uses not covered in this chapter shall be subject to the approval of the building official.
Structural systems and members thereof shall be designed to have adequate stiffness to limit deflections as indicated in Table 1604A.3.
TABLE 1604A.3
DEFLECTION LIMITSa, b, c, h, i
| CONSTRUCTION | L or Lr | E, S or W f | D + (L or Lr)d, g |
| Roof members:e | |||
| Supporting plaster or stucco ceiling | l/360 | l/360 | l/240 |
| Supporting nonplaster ceiling | l/240 | l/240 | l/180 |
| Not supporting ceiling | l/180 | l/180 | l/120 |
| Floor members | l/360 | — | l/240 |
| Exterior walls: | |||
| With plaster or stucco finishes | — | l/360 | — |
| With other brittle finishes | — | l/240 | — |
| With flexible finishes | — | l/120 | — |
| Veneered walls, anchored veneers and adhered veneers over 1 inch (25 mm) thick, including the mortar backing | — | l/600 | — |
| Interior partitions:b | |||
| With plaster or stucco finishes | l/360 | — | — |
| With other brittle finishes | l/240 | — | — |
| With flexible finishes | l/120 | — | — |
| Farm buildings | — | — | l/180 |
| Greenhouses | — | — | l/120 |
For SI: 1 foot = 304.8 mm.
- For structural roofing and siding made of formed metal sheets, the total load deflection shall not exceed l/60. For secondary roof structural members supporting formed metal roofing, the live load deflection shall not exceed l/150. For secondary wall members supporting formed metal siding, the design wind load deflection shall not exceed l/90. For roofs, this exception only applies when the metal sheets have no roof covering.
- Flexible, folding and portable partitions are not governed by the provisions of this section. The deflection criterion for interior partitions is based on the horizontal load defined in Section 1607A.16.
- See Section 2403 for glass supports.
- The deflection limit for the D + (L + Lr) load combination only applies to the deflection due to the creep component of long-term dead load deflection plus the short-term live load deflection. For lumber, structural glued laminated timber, prefabricated wood I-joists and structural composite lumber members that are dry at time of installation and used under dry conditions in accordance with the ANSI/AWC NDS, the creep component of the long-term deflection shall be permitted to be estimated as the immediate dead load deflection resulting from 0.5D. For lumber and glued laminated timber members installed or used at all other moisture conditions or cross laminated timber and wood structural panels that are dry at time of installation and used under dry conditions in accordance with the ANSI/AWC NDS, the creep component of the long-term deflection is permitted to be estimated as the immediate dead load deflection resulting from D. The value of 0.5D shall not be used in combination with ANSI/AWC NDS provisions for long-term loading.
- The preceding deflections do not ensure against ponding. Roofs that do not have sufficient slope or camber to ensure adequate drainage shall be investigated for ponding. See Chapter 8 of ASCE 7.
- The wind load shall be permitted to be taken as 0.42 times the "component and cladding" loads or directly calculated using the 10-year mean return interval wind speed for the purpose of determining deflection limits in Table 1604A.3. Where framing members support glass, the deflection limit therein shall not exceed that specified in Section 1604A.3.7
- For steel structural members, the deflection due to creep component of long-term dead load shall be permitted to be taken as zero.
- For aluminum structural members or aluminum panels used in skylights and sloped glazing framing, roofs or walls of sunroom additions or patio covers not supporting edge of glass or aluminum sandwich panels, the total load deflection shall not exceed l/60. For continuous aluminum structural members supporting edge of glass, the total load deflection shall not exceed l/175 for each glass lite or l/60 for the entire length of the member, whichever is more stringent. For aluminum sandwich panels used in roofs or walls of sunroom additions or patio covers, the total load deflection shall not exceed 1/120.
- l = Length of the member between supports. For cantilever members, l shall be taken as twice the length of the cantilever.
The deflection of steel structural members shall not exceed that permitted by AISC 360, AISI S100, ASCE 8, SJI 100 or SJI 200, as applicable.
The deflection of masonry structural members shall not exceed that permitted by TMS 402.
The deflection of aluminum structural members shall not exceed that permitted by AA ADM.
The deflection limits of Section 1604A.3.1 shall be used unless more restrictive deflection limits are required by a referenced standard for the element or finish material.
The deflection of framing members supporting glass subjected to 0.6 times the "component and cladding" wind loads shall not exceed either of the following:
- 1/175 of the length of span of the framing member, for framing members having a length not more than 13 feet 6 inches (4115 mm).
- 1/240 of the length of span of the framing member + 1/4 inch (6.4 mm), for framing members having a length greater than 13 feet 6 inches (4115 mm).
The maximum span-depth ratio for any roof or floor diaphragm consisting of steel and composite steel slab decking shall not exceed those given in Table 1604A.4, unless test data and design calculations acceptable to the enforcement agency are submitted and approved for the use of other span-depth ratios. Concrete diaphragms shall not exceed the span depth ratios for the equivalent composite steel-slab diaphragm in Table 1604A.4.
Deflection criteria for materials not specified shall be developed by the project architect or structural engineer in a manner consistent with the provisions of this section and approved by the enforcement agency.
Load effects on structural members and their connections shall be determined by methods of structural analysis that take into account equilibrium, general stability, geometric compatibility and both short- and long-term material properties.
Members that tend to accumulate residual deformations under repeated service loads shall have included in their analysis the effects of added deformations expected to occur during their service life.
Any system or method of construction to be used shall be based on a rational analysis in accordance with well-established principles of mechanics. Such analysis shall result in a system that provides a complete load path capable of transferring loads from their point of origin to the load-resisting elements.
The total lateral force shall be distributed to the various vertical elements of the lateral force-resisting system in proportion to their rigidities, considering the rigidity of the horizontal bracing system or diaphragm. Rigid elements assumed not to be a part of the lateral force-resisting system are permitted to be incorporated into buildings provided that their effect on the action of the system is considered and provided for in the design. Structural analysis shall explicitly include consideration of stiffness of diaphragms in accordance with ASCE 7, Section 12.3.1. A diaphragm is rigid for the purpose of distribution of story shear and torsional moment when the lateral deformation of the diaphragm is less than or equal to two times the average story drift. Where required by ASCE 7, provisions shall be made for the increased forces induced on resisting elements of the structural system resulting from torsion due to eccentricity between the center of application of the lateral forces and the center of rigidity of the lateral force-resisting system.
Every structure shall be designed to resist the effects caused by the forces specified in this chapter, including overturning, uplift and sliding. Where sliding is used to isolate the elements, the effects of friction between sliding elements shall be included as a force.
TABLE 1604A.4
MAXIMUM HORIZONTAL DIAPHRAGM SPAN AND SPAN-DEPTH RATIOS1, 3, 4
| FLEXIBILITY FACTOR(F)2 | MAXIMUM DIAPHRAGM SPAN FOR MASONRY OR CONCRETE WALLS (feet) | DIAPHRAGM SPAN-DEPTH LIMITATION | |||
| Rotation (torsion) Not Considered in Diaphragm | Rotation (torsion) Considered in Diaphragm | ||||
| Masonry or Concrete Walls | Flexible Walls | Masonry or Concrete Walls | Flexible Walls | ||
| More than 150 | Not to be used | Not to be used | 2:1 | Not to be used | 11/2:1 |
| 70—150 | 200 | 2:1 or as required for deflection | 3:1 | Not to be used | 2:1 |
| 10—70 | 400 | 21/2:1 or as required for deflection | 4:1 | As required for deflection | 21/2:1 |
| 1—10 | No limitation | 3:1 or as required for deflection | 5:1 | As required for deflection | 3:1 |
| Less than 1 | No limitation | As required for deflection | No limitation | As required for deflection | 31/2:1 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 plf = 14.594 N/m, 1 psi = 6894 Pa
- Diaphragms shall satisfy span-depth limitations based on flexibility.
- Flexibility factor (F) is the average deflection in micro inches (10-6) or µm of the diaphragm web per foot (m) of span stressed with a shear of 1 pound per foot (N/m).
- The total deflection Δ of the diaphragm may be computed from the equation: Δ = Δf + Δw.Δf = Flexural deflection of the diaphragm determined in the same manner as the deflection of beams. The flexural stiffness of the web of diaphragms consisting of bare steel decking shall be neglected.Δw = Web deflection of the diaphragm may be determined solving the following equation:
L = Distance in feet (m) between the vertical resisting element (such as a shear wall) and the point to which the deflection is to be determined.qave = Average shear in the diaphragm in pounds per foot (N/m) over length L. - When applying these limitations to cantilevered diaphragms, the allowable span-depth ratio will be half of that shown.
Each building and structure shall be assigned a risk category in accordance with Table 1604A.5. Where a referenced standard specifies an occupancy category, the risk category shall not be taken as lower than the occupancy category specified therein. Where a referenced standard specifies that the assignment of a risk category be in accordance with ASCE 7, Table 1.5-1, Table 1604A.5 shall be used in lieu of ASCE 7, Table 1.5-1.
Exception: The assignment of buildings and structures to Tsunami Risk Categories III and IV is permitted to be in accordance with Section 6.4 of ASCE 7.
TABLE 1604A.5
RISK CATEGORY OF BUILDINGS AND OTHER STRUCTURES
| RISK CATEGORY | NATURE OF OCCUPANCY |
| I | Buildings and other structures that represent a low hazard to human life in the event of failure, including but not limited to:
|
| II | Buildings and other structures except those listed in Risk Categories I, III and IV. |
| III | Buildings and other structures that represent a substantial hazard to human life in the event of failure, including but not limited to:
|
| IV | Buildings and other structures designated as essential facilities, including but not limited to:
|
- For purposes of occupant load calculation, occupancies required by Table 1004.5 to use gross floor area calculations shall be permitted to use net floor areas to determine the total occupant load.
- Where approved by the building official, the classification of buildings and other structures as Risk Category III or IV based on their quantities of toxic, highly toxic or explosive materials is permitted to be reduced to Risk Category II, provided that it can be demonstrated by a hazard assessment in accordance with Section 1.5.3 of ASCE 7 that a release of the toxic, highly toxic or explosive materials is not sufficient to pose a threat to the public.
Where a building or structure is occupied by two or more occupancies not included in the same risk category, it shall be assigned the classification of the highest risk category corresponding to the various occupancies. Where buildings or structures have two or more portions that are structurally separated, each portion shall be separately classified. Where a separated portion of a building or structure provides required access to, required egress from or shares life safety components with another portion having a higher risk category, both portions shall be assigned to the higher risk category.
Exception: Where a storm shelter designed and constructed in accordance with ICC 500 is provided in a building, structure or portion thereof normally occupied for other purposes, the risk category for the normal occupancy of the building shall apply unless the storm shelter is a designated emergency shelter in accordance with Table 1604A.5.
The building official is authorized to require an engineering analysis or a load test, or both, of any construction whenever there is reason to question the safety of the construction for the intended occupancy. Engineering analysis and load tests shall be conducted in accordance with Section 1708A.
Materials and methods of construction that are not capable of being designed by approved engineering analysis or that do not comply with the applicable referenced standards, or alternative test procedures in accordance with Section 1707A, shall be load tested in accordance with Section 1709A.
Buildings and other structures, and portions thereof, shall be provided with anchorage in accordance with Sections 1604A.8.1 through 1604A.8.3, as applicable.
Walls that provide vertical load-bearing resistance or lateral shear resistance for a portion of the structure shall be anchored to the roof and to all floors and members that provide lateral support for the wall or that are supported by the wall. The connections shall be capable of resisting the horizontal forces specified in Section 1.4.4 of ASCE 7 for walls of structures assigned to Seismic Design Category A and to Section 12.11 of ASCE 7 for walls of structures assigned to all other seismic design categories. For anchorage of concrete or masonry walls to roof and floor diaphragms, the out-ofplane strength design force shall not be less than 280 lb/linear ft (4.09 kN/m) of wall. Required anchors in masonry walls of hollow units or cavity walls shall be embedded in a reinforced grouted structural element of the wall. See Sections 1609 for wind design requirements and 1613A for earthquake design requirements.
Where supported by attachment to an exterior wall, decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads as applicable. Such attachment shall not be accomplished by the use of toenails or nails subject to withdrawal. Where positive connection to the primary building structure cannot be verified during inspection, decks shall be self-supporting. Connections of decks with cantilevered framing members to exterior walls or other framing members shall be designed for both of the following:
- The reactions resulting from the dead load and live load specified in Table 1607A.1, or the snow load specified in Section 1608A, in accordance with Section 1605A, acting on all portions of the deck.
- The reactions resulting from the dead load and live load specified in Table 1607A.1, or the snow load specified in Section 1608A, in accordance with Section 1605A, acting on the cantilevered portion of the deck, and no live load or snow load on the remaining portion of the deck.
Lateral force-resisting systems shall meet seismic detailing requirements and limitations prescribed in this code and ASCE 7, Chapters 11, 12, 13, 15, 17 and 18 as applicable, even where wind load effects are greater than seismic load effects.
Exception: References within ASCE 7 to Chapter 14 shall not apply, except as specifically required herein.
Loads and load combinations on storm shelters shall be determined in accordance with ICC 500.
Buildings and other structures and portions thereof shall be designed to resist the strength load combinations specified in ASCE 7, Section 2.3, the allowable stress design load combinations specified in ASCE 7, Section 2.4, or the alternative allowable stress design load combinations of Section 1605A.2.
Exceptions:
- The modifications to load combinations of ASCE 7, Section 2.3, ASCE 7, Section 2.4, and Section 1605A.2 specified in ASCE 7, Chapters 18 and 19 shall apply.
- Where the allowable stress design load combinations of ASCE 7, Section 2.4 are used, flat roof snow loads of 30 pounds per square foot (1.44 kN/m2) and roof live loads of 30 pounds per square foot (1.44 kN/m2) or less need not be combined with seismic load. Where flat roof snow loads exceed 30 pounds per square foot (1.44 kN/m2), 20 percent shall be combined with seismic loads.
- Where the allowable stress design load combinations of ASCE 7, Section 2.4 are used, crane hook loads need not be combined with roof live loads or with more than three-fourths of the snow load or one-half of the wind loads.
Regardless of which load combinations are used to design for strength, where overall structure stability (such as stability against overturning, sliding, or buoyancy) is being verified, use of the load combinations specified in Section 2.3 or 2.4 of ASCE 7, and in Section 1605A.2 shall be permitted. Where the load combinations specified in ASCE 7, Section 2.3 are used, strength reduction factors applicable to soil resistance shall be provided by a registered design professional. The stability of retaining walls shall be verified in accordance with Section 1807A.2.3. When using allowable stress design, factor of safety for soil bearing values shall not be less than the overstrength factor of the structures supported. Strength design for foundation geotechnical capacity shall be in accordance with ASCE 7, Section 12.13.5 for all strength design load combinations, except that Resistance Factor (ø) shall be permitted to be 1.0 for load combinations with overstrength factor. Allowable stress design for foundation geotechnical capacity shall be in accordance with ASCE 7, Section 12.13.6 for all allowable stress design load combinations, and shall be established to be consistent with strength design requirements in ASCE 7, Section 12.13.5.
In lieu of the load combinations in ASCE 7, Section 2.4, structures and portions thereof shall be permitted to be designed for the most critical effects resulting from the following combinations. Where using these alternative allowable stress load combinations that include wind or seismic loads, allowable stresses are permitted to be increased or load combinations reduced where permitted by the material chapter of this code or the referenced standards. For load combinations that include the counteracting effects of dead and wind loads, only two-thirds of the minimum dead load likely to be in place during a design wind event shall be used. Where using these alternative load combinations to evaluate sliding, overturning and soil bearing at the soil-structure interface, the reduction of foundation overturning from Section 12.13.4 in ASCE 7 shall not be used. Where using these alternative basic load combinations for proportioning foundations for loadings, which include seismic loads, the vertical seismic load effect, Ev, in Equation 12.4-4 of ASCE 7 is permitted to be taken equal to zero. Where required by ASCE 7, Chapters 12, 13 and 15, the load combinations including overstrength of ASCE 7, Section 2.3.6 shall be used. Each load combination shall be investigated with one or more of the variable loads set to zero.
(Equation 16A-1)
(Equation 16A-2)
(Equation 16A-3)
(Equation 16A-4)
(Equation 16A-5)
(Equation 16A-6)
Exceptions:
- Crane hook loads need not be combined with roof live loads or with more than three-fourths of the snow load or one-half of the wind load.
- Flat roof snow loads of 30 pounds per square foot (1.44 kN/m2) or less and roof live loads of 30 pounds per square foot (1.44 kN/m2) or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 pounds per square foot (1.44 kN/m2), 20 percent shall be combined with seismic loads.
Modify the text of ICC 300 as follows:
Modify Section 303.5.2 by adding Equation 3-5a as follows:
(Equation 3-5a)
Dead loads are those loads defined in Chapter 2 of this code. Dead loads shall be considered to be permanent loads.
For purposes of design, the actual weights of materials of construction shall be used. In the absence of definite information, values used shall be subject to the approval of the building official.
In determining dead loads for purposes of design, the weight of fixed service equipment, including the maximum weight of the contents of fixed service equipment, shall be included. The components of fixed service equipment that are variable, such as liquid contents and movable trays, shall not be used to counteract forces causing overturning, sliding, and uplift conditions in accordance with Section 1.3.6 of ASCE 7.
Exceptions:
- Where force effects are the result of the presence of the variable components, the components are permitted to be used to counter those load effects. In such cases, the structure shall be designed for force effects with the variable components present and with them absent.
- For the calculation of seismic force effects, the components of fixed service equipment that are variable, such as liquid contents and movable trays, need not exceed those expected during normal operation.
The weight of photovoltaic panel systems, their support system, and ballast shall be considered as dead load.
The weight of all landscaping and hardscaping materials for vegetative and landscaped roofs shall be considered as dead load. The weight shall be computed considering both fully saturated soil and drainage layer materials and fully dry soil and drainage layer materials to determine the most severe load effects on the structure.
The design dead load shall provide for the weight of at least one additional roof covering in addition to other applicable loadings if the new roof covering is permitted to be applied over the original roofing without its removal, in accordance with Section 1512.
| OCCUPANCY OR USE | UNIFORM
(psf)
|
CONCENTRATED
(pounds)
|
ALSO SEE
SECTION
|
||
| 1. | Apartments (see residential) | — | — | — | |
| 2. | Access floor systems | Office use | 50 | 2,000 | — |
| Computer use | 100 | 2,000 | — | ||
| 3. | Armories and drill rooms | 150b | — | — | |
| 4. | Assem bly areasc, e | Fixed seats (fastened to floor) | 60a | — | — |
| Follow spot, projections and control rooms | 50 | ||||
| Lobbies | 100a | ||||
| Movable seats | 100a | ||||
| Stage floors | 150b | ||||
| Platforms (assembly) | 100a | ||||
| Bleachers, folding and telescopic seating and grandstandsg | 100a (See Section 1607A.19) | ||||
| Stadiums and arenas with fixed seats
(fastened to the floor)
|
60a (See Section 1607A.19) | ||||
| Other assembly areas | 100a | ||||
| 5. | Balconies and decks | 1.5 times the live load for the area served, not required to exceed 100 | — | — | |
| 6. | Catwalks for maintenance and service access | 40 | 300 | — | |
| 7. | Cornices | 60 | — | — | |
| 8. | Corridors | First floor | 100 | — | — |
| Other floors | Same as occupancy
served except as indicated
|
||||
| 9. | Dining rooms and restaurants | 100a | — | — | |
| 10. | Dwellings (see residential) | — | — | — | |
| 11. | Elevator machine room and control room grating
(on area of 2 inches by 2 inches)
|
— | 300 | — | |
| 12. | Finish light floor plate construction (on area of 1 inch by 1 inch) | — | 200 | — | |
| 13. | Fire escapes | 100 | — | — | |
| On single-family dwellings only | 40 | ||||
| 14. | Fixed ladders | See Section 1607A.17 | — | ||
| 15. | Garages | Passenger vehicles only | 40c | See Section 1607A.7 | — |
| Trucks and buses | See Section 1607A.8 | ||||
|
16.
|
Handrails, guards and grab bars | See Section 1607A.9 | — | ||
|
17.
|
Helipads | See Section 1607A.6 | — | ||
|
18.
|
Hospitals
[OSHPD 1 & 4]
|
Corridors above first floor | 80 | 1,000 | — |
| Operating rooms, laboratories | 60a | 1,000 | |||
| Patient rooms | 40 | 1,000 | |||
|
19.
|
Hotels (see residential) | — | — | — | |
|
20.
|
Libraries | Corridors above first floor | 80 | 1,000 | — |
| Reading rooms | 60 | 1,000 | — | ||
| Stack rooms | 150b | 1,000 | Section 1607A.18 | ||
|
21.
|
Manufacturing | Heavy | 250b | 3,000 | — |
| Light | 125b | 2,000 | — | ||
|
22.
|
Marquees, except one- and two-family dwellings | 75 | — | — | |
|
23.
|
Office buildingsb | Corridors above first floor | 80 | 2,000 | — |
| File and computer rooms shall be designed for heavier loads based on anticipated occupancy | — | — | |||
| Lobbies and first-floor corridors | 100 | 2,000 | |||
| Offices | 50 | 2,000 | |||
|
24.
|
Penal institutions | Cell blocks | 40 | — | — |
| Corridors | 100 | ||||
|
25.
|
Recreational uses | Bowling alleys, poolrooms and similar uses | 75a | — | — |
| Dance halls and ballrooms | 100a | ||||
| Gymnasiums | 100a | ||||
| Ice skating rinks | 250b | ||||
| Roller skating rinks | 100a | ||||
|
26.
|
Residential | One- and two-family dwellings: | — | Section 1607A.22 | |
| Uninhabitable attics without storage | 10 | ||||
| Uninhabitable attics with storage | 20 | ||||
| Habitable attics and sleeping areas | 30 | ||||
| Canopies, including marquees | 20 | ||||
| All other areas | 40 | ||||
| Hotels and multifamily dwellings: | |||||
| Private rooms and corridors serving them | 40 | ||||
| Public roomsa and corridors serving them | 100 | ||||
|
27.
|
Roofs | Ordinary flat, pitched, and curved roofs (that are not occupiable) | 20 | — | Section 1607A.14.2 |
| Roof areas used for assembly purposes | 100a | — | |||
| Roof areas used for occupancies other than assembly | Same as occupancy served | — | |||
| Vegetative and landscaped roofs: | — | ||||
| Roof areas not intended for occupancy | 20 | — | |||
| Roof areas used for assembly purposes | 100a | — | |||
| Roof areas used for other occupancies | Same as occupancy served | — | |||
| Awnings and canopies: | — | ||||
| Fabric construction supported by a skeleton structure | 5a | — | |||
| All other construction, except one- and two-family dwellings | 20 | — | |||
| Primary roof members exposed to a work floor: | Section 1607A.15.2 | ||||
| Single panel point of lower chord of roof trusses or any point along primary structural members supporting roofs over manufacturing, storage warehouses, and repair garages | — | 2,000 | |||
| All other primary roof members | — | 300 | |||
| All roof surfaces subject to maintenance workers | — | 300 | |||
|
28.
|
Schoolsd | Classrooms | 40
[DSA-SS]
50 f |
1,000 | — |
| Corridors above first floor | 80 | 1,000 | |||
| First-floor corridors | 100 | 1,000 | |||
|
29.
|
Scuttles, skylight ribs and accessible ceilings | — | 200 | — | |
|
30.
|
Sidewalks, vehicular driveways and yards, subject to trucking | 250b | 8,000 | Section 1607A.20 | |
|
31.
|
Stairs and exits | One- and two-family dwellings | 40 | 300 | Section 1607A.21 |
| All other | 100 | 300 | Section 1607A.21 | ||
|
32.
|
Storage areas above ceilings | 20 | — | — | |
|
33.
|
Storage warehouses (shall be designed for heavier loads if required for anticipated storage) | Heavy | 250b | — | — |
| Light | 125b | ||||
|
34.
|
Stores | Retail: | — | ||
| First floor | 100 | 1,000 | |||
| Upper floors | 75 | 1,000 | |||
| Wholesale, all floors | 125b | 1,000 | |||
|
35.
|
Vehicle barriers | See Section 1607A.10 | — | ||
|
36.
|
Walkways and elevated platforms (other than exitways) | 60 | — | — | |
|
37.
|
Yards and terraces, pedestrianh | 100a | — | — | |
|
38.
|
Storage racks and wall-hung cabinets | Total loadsd | — | — | |
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm2, 1 square foot = 0.0929 m2, 1 pound per square foot = 0.0479 kN/m2, 1 pound = 0.004448 kN, 1 pound per cubic foot = 16 kg/m3.
- Live load reduction is not permitted.
- Live load reduction is only permitted in accordance with Section 1607A.12.1.2 or Item 1 of Section 1607A.12.2.
- Live load reduction is only permitted in accordance with Section 1607A.12.1.3 or Item 2 of Section 1607A.12.2.
-
The minimum vertical design live load shall be as follows:
Paper media: 12-inch-deep shelf 33 pounds per lineal foot 15-inch-deep shelf 41 pounds per lineal foot, or 33 pounds per cubic foot per total volume of the rack or cabinet, whichever is less. Film media: 18-inch-deep shelf 100 pounds per lineal foot, or 50 pounds per cubic foot per total volume of the rack or cabinet, whichever is less. Other media: 20 pounds per cubic foot or 20 pounds per square foot, whichever is less, but not less than actual loads. -
- Gridirons and fly galleries: 75 pounds per square foot uniform live load.
- Loft block wells: 250 pounds per lineal foot vertical load and lateral load.
- Head block wells and sheave beams: 250 pounds per lineal foot vertical load and lateral load. Head block wells and sheave beams shall be designed for all tributary loft block well loads. Sheave blocks shall be designed with a safety factor of five.
- Scenery beams where there is no gridiron: 300 pounds per lineal foot vertical load and lateral load.
- Ceiling framing over stages shall be designed for a uniform live load of 20 pounds per square foot. For members supporting a tributary area of 200 square feet or more, this additional load may be reduced to 15 pounds per square foot.
- [DSA-SS] Live load reduction is not permitted for classrooms classified as Group A occupancies.
- [DSA-SS] The minimum uniform live load for a press box floor or accessible roof with railing is 100 psf.
- [DSA-SS] Item 37 applies to pedestrian bridges and walkways that are not subjected to uncontrolled vehicle access.
For occupancies or uses not designated in Section 1607A, the live load shall be determined in accordance with a method approved by the building official.
The live loads used in the design of buildings and other structures shall be the maximum loads expected by the intended use or occupancy but shall not be less than the minimum uniformly distributed live loads given in Table 1607A.1.
Floors, roofs and other similar surfaces shall be designed to support the uniformly distributed live loads prescribed in Section 1607A.3 or the concentrated live loads, given in Table 1607A.1, whichever produces the greater load effects. Unless otherwise specified, the indicated concentration shall be assumed to be uniformly distributed over an area of 21/2 feet by 21/2 feet (762 mm by 762 mm) and shall be located so as to produce the maximum load effects in the structural members.
In office buildings and in other buildings where partition locations are subject to change, provisions for partition weight shall be made, whether or not partitions are shown on the construction documents, unless the specified live load is 80 psf (3.83 kN/m2) or greater. The partition load shall be not less than a uniformly distributed live load of 15 psf (0.72 kN/m2).
Helipads shall be designed for the following live loads:
- A uniform live load, L, as specified in Items 1.1 and 1.2. This load shall not be reduced.
- A single concentrated live load, L, of 3,000 pounds (13.35 kN) applied over an area of 4.5 inches by 4.5 inches (114 mm by 114 mm) and located so as to produce the maximum load effects on the structural elements under consideration. The concentrated load is not required to act concurrently with other uniform or concentrated live loads.
- Two single concentrated live loads, L, 8 feet (2438 mm) apart applied on the landing pad (representing the helicopter's two main landing gear, whether skid type or wheeled type), each having a magnitude of 0.75 times the maximum take-off weight of the helicopter, and located so as to produce the maximum load effects on the structural elements under consideration. The concentrated loads shall be applied over an area of 8 inches by 8 inches (203 mm by 203 mm) and are not required to act concurrently with other uniform or concentrated live loads.
Landing areas designed for a design basis helicopter with maximum take-off weight of 3,000 pounds (13.35 kN) shall be identified with a 3,000-pound (13.34 kN) weight limitation. The landing area weight limitation shall be indicated by the numeral "3" (kips) located in the bottom right corner of the landing area as viewed from the primary approach path. The indication for the landing area weight limitation shall be a minimum 5 feet (1524 mm) in height.
Floors in garages or portions of a building used for the storage of motor vehicles shall be designed for the uniformly distributed live loads indicated in Table 1607A.1 or the following concentrated load:
- For garages restricted to passenger vehicles accommodating not more than nine passengers, 3,000 pounds (13.35 kN) acting on an area of 4.5 inches by 4.5 inches (114 mm by 114 mm).
- For mechanical parking structures without slab or deck that are used for storing passenger vehicles only, 2,250 pounds (10 kN) per wheel.
Where any structure does not restrict access for vehicles that exceed a 10,000-pound (4536 kg) gross vehicle weight rating, those portions of the structure subject to such loads shall be designed using the vehicular live loads, including consideration of impact and fatigue, in accordance with the codes and specifications required by the jurisdiction having authority for the design and construction of the roadways and bridges in the same location of the structure.
Where a structure or portions of a structure are accessed and loaded by fire department access vehicles and other similar emergency vehicles, the structure shall be designed for the greater of the following loads:
- The actual operational loads, including outrigger reactions and contact areas of the vehicles as stipulated and approved by the building official.
- The live loading specified in Section 1607A.8.1.
Garages designed to accommodate vehicles that exceed a 10,000-pound (4536 kg) gross vehicle weight rating, shall be designed using the live loading specified by Section 1607A.8.1. For garages the design for impact and fatigue is not required.
Exception: The vehicular live loads and load placement are allowed to be determined using the actual vehicle weights for the vehicles allowed onto the garage floors, provided that such loads and placement are based on rational engineering principles and are approved by the building official, but shall be not less than 50 psf (2.9 kN/m2). This live load shall not be reduced.
Where a structure is intended to have forklifts or other movable equipment present, the structure shall be designed for the total vehicle or equipment load and the individual wheel loads for the anticipated vehicles as specified by the owner of the facility. These loads shall be posted in accordance with Section 1607A.8.5.
Impact loads and fatigue loading shall be considered in the design of the supporting structure. For the purposes of design, the vehicle and wheel loads shall be increased by 30 percent to account for impact.
The maximum weight of vehicles allowed into or on a garage or other structure shall be posted by the owner or the owner's authorized agent in accordance with Section 106.1.
Handrails and guards shall be designed and constructed for the structural loading conditions set forth in Section 1607A.9.1. Grab bars, shower seats and accessible benches shall be designed and constructed for the structural loading conditions set forth in Section 1607A.9.2.
Handrails and guards shall be designed to resist a linear load of 50 pounds per linear foot (plf) (0.73 kN/m) in accordance with Section 4.5.1.1 of ASCE 7. Glass handrail assemblies and guards shall comply with Section 2407.
Exceptions:
- For one- and two-family dwellings, only the single concentrated load required by Section 1607A.9.1.1 shall be applied.
- In Group I-3, F, H and S occupancies, for areas that are not accessible to the general public and that have an occupant load less than 50, the minimum load shall be 20 pounds per foot (0.29 kN/m).
Grab bars, shower seats and accessible benches shall be designed to resist a single concentrated load of 250 pounds (1.11 kN) applied in any direction at any point on the grab bar, shower seat, or seat of the accessible bench so as to produce the maximum load effects. [DSA-AC] See Chapter 11A, Section 1127A.4 and Chapter 11B, Sections 11B-609.8, 11B-610.4 and 11B-903.6 for grab bars, shower seats and dressing room bench seats, as applicable.
Vehicle barriers for passenger vehicles shall be designed to resist a concentrated load of 6,000 pounds (26.70 kN) in accordance with Section 4.5.3 of ASCE 7. Garages accommodating trucks and buses shall be designed in accordance with an approved method that contains provisions for traffic railings.
The live loads specified in Sections 1607A.3 through 1607A.10 shall be assumed to include adequate allowance for ordinary impact conditions. Provisions shall be made in the structural design for uses and loads that involve unusual vibration and impact forces.
Members, elements and components subject to dynamic loads from elevators shall be designed for impact loads and deflection limits prescribed by ASME A17.1/CSA B44.
In addition to any other applicable live loads, structural elements that support hoists for façade access and building maintenance equipment shall be designed for a live load of 2.5 times the rated load of the hoist or the stall load of the hoist, whichever is larger.
In addition to any other applicable live loads, fall arrest, lifeline, and rope descent system anchorages and structural elements that support these anchorages shall be designed for a live load of not less than 3,100 pounds (13.8 kN) for each attached line, in any direction that the load can be applied.
Anchorages of horizontal lifelines and the structural elements that support these anchorages shall be designed for the maximum tension that develops in the horizontal lifeline from these live loads.
Except for uniform live loads at roofs, all other minimum uniformly distributed live loads, Lo, in Table 1607A.1 are permitted to be reduced in accordance with Section 1607A.12.1 or 1607A.12.2. Uniform live loads at roofs are permitted to be reduced in accordance with Section 1607.14.2.
Subject to the limitations of Sections 1607A.12.1.1 through 1607A.12.1.3 and Table 1607A.1, members for which a value of KLLAT is 400 square feet (37.16 m2) or more are permitted to be designed for a reduced uniformly distributed live load, L, in accordance with the following equation:
(Equation 16A-7)
Lo = Unreduced design live load per square foot (m2) of area supported by the member (see Table 1607A.1).
AT = Tributary area, in square feet (m2).
L shall be not less than 0.50Lo for members supporting one floor and L shall be not less than 0.40Lo for members supporting two or more floors.
| ELEMENT | KLL |
| Interior columns | 4 |
| Exterior columns without cantilever slabs | 4 |
| Edge columns with cantilever slabs | 3 |
| Corner columns with cantilever slabs | 2 |
| Edge beams without cantilever slabs | 2 |
| Interior beams | 2 |
| Members not previously identified including: | |
| Edge beams with cantilever slabs | |
| Cantilever beams | |
| One-way slabs | 1 |
| Two-way slabs | |
| Members without provisions for continuous shear transfer normal to their span |
Live loads that exceed 100 psf (4.79 kN/m2) shall not be reduced.
Exceptions:
- The live loads for members supporting two or more floors are permitted to be reduced by not greater than 20 percent, but the live load shall be not less than L as calculated in Section 1607A.12.1.
- For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.
The live loads shall not be reduced in passenger vehicle garages.
Exception: The live loads for members supporting two or more floors are permitted to be reduced by not greater than 20 percent, but the live load be shall be not less than L as calculated in Section 1607A.12.1.
As an alternative to Section 1607A.12.1 and subject to the limitations of Table 1607A.1, uniformly distributed live loads are permitted to be reduced in accordance with the following provisions. Such reductions shall apply to slab systems, beams, girders, columns, piers, walls and foundations.
- A reduction shall not be permitted in passenger vehicle parking garages except that the live loads for members supporting two or more floors are permitted to be reduced by not greater than 20 percent.
- For live loads not exceeding 100 psf (4.79 kN/m2), the design live load for any structural member supporting 150 square feet (13.94 m2) or more is permitted to be reduced in accordance with Equation 16-8
- For one-way slabs, the area, A, for use in Equation 16-8 shall not exceed the product of the slab span and a width normal to the span of 0.5 times the slab span.
(Equation 16A-8)
For SI: R = 0.861(A - 13.94)
Such reduction shall not exceed the smallest of:
- 40 percent for members supporting one floor.
- 60 percent for members supporting two or more floors.
- R as determined by the following equation:
(Equation 16A-9)
A = Area of floor supported by the member, square feet (m2).
R = Reduction in percent.
Where uniform floor live loads are involved in the design of structural members arranged so as to create continuity, the minimum applied loads shall be the full dead loads on all spans in combination with the floor live loads on spans selected to produce the greatest load effect at each location under consideration. Floor live loads are permitted to be reduced in accordance with Section 1607A.12 .
The structural supports of roofs and marquees shall be designed to resist wind and, where applicable, snow and earthquake loads, in addition to the dead load of construction and the appropriate live loads as prescribed in this section, or as set forth in Table 1607A.1. The live loads acting on a sloping surface shall be assumed to act vertically on the horizontal projection of that surface.
Where uniform roof live loads are reduced to less than 20 psf (0.96 kN/m2) in accordance with Section 1607A.14.2.1 and are applied to the design of structural members arranged so as to create continuity, the reduced roof live load shall be applied to adjacent spans or to alternate spans, whichever produces the most unfavorable load effect. See Section 1607A.14.2 for reductions in minimum roof live loads and Section 7.5 of ASCE 7 for partial snow loading.
The minimum uniformly distributed live loads of roofs and marquees, Lo, in Table 1607A.1 are permitted to be reduced in accordance with Section 1607A.14.2.1.
Ordinary flat, pitched and curved roofs, and awnings and canopies other than of fabric construction supported by a skeleton structure, are permitted to be designed for a reduced uniformly distributed roof live load, Lr, as specified in the following equations or other controlling combinations of loads as specified in Section 1605, whichever produces the greater load effect.
In structures such as greenhouses, where special scaffolding is used as a work surface for workers and materials during maintenance and repair operations, a lower roof load than specified in the following equations shall not be used unless approved by the building official. Such structures shall be designed for a minimum roof live load of 12 psf (0.58 kN/m2).
(Equation 16A-10) where: 12 ≤ Lr ≤ 20
For SI: Lr = LoR1R2
where: 0.58 ≤ Lr ≤ 0.96
Lo = Unreduced roof live load per square foot (m2) of horizontal projection supported by the member (see Table 1607.1).
Lr = Reduced roof live load per square foot (m2) of horizontal projection supported by the member.
The reduction factors R1 and R2 shall be determined as follows:
(Equation 16A-11) 
(Equation 16A-12) For SI: 1.2 - 0.011At for 18.58 square meters < At < 55.74 square meters
(Equation 16A-13) At = Tributary area (span length multiplied by effective width) in square feet (m2) supported by the member, and
(Equation 16A-14) 
(Equation 16A-15) 
(Equation 16A-16) Areas of roofs that are occupiable, such as vegetative roofs, landscaped roofs or for assembly or other similar purposes, and marquees are permitted to have their uniformly distributed live loads reduced in accordance with Section 1607A.12.
Roof structures that provide support for photovoltaic panel systems shall be designed in accordance with Sections 1607A.14.4.1 through 1607A.14.4.5, as applicable.
Roof structures that support photovoltaic panel systems shall be designed to resist each of the following conditions:
- Exception: Roof live loads need not be applied to the area covered by photovoltaic panels where the clear space between the panels and the roof surface is 24 inches (610 mm) or less.
- Applicable uniform and concentrated roof loads without the photovoltaic panel system present.
The structure of a roof that supports solar photovoltaic panels or modules shall be designed to accommodate the full solar photovoltaic panels or modules and ballast dead load, including concentrated loads from support frames in combination with the loads from Section 1607A.14.4.1 and other applicable loads. Where applicable, snow drift loads created by the photovoltaic panels or modules shall be included.
Structures with open grid framing and without a roof deck or sheathing supporting photovoltaic panel systems shall be designed to support the uniform and concentrated roof live loads specified in Section 1607A.14.4.1, except that the uniform roof live load shall be permitted to be reduced to 12 psf (0.57 kN/m2).
Roof structures that provide support for ballasted photovoltaic panel systems shall be designed, or analyzed, in accordance with Section 1604A.4; checked in accordance with Section 1604A.3.6 for deflections; and checked in accordance with Section 1611A for ponding.
The crane live load shall be the rated capacity of the crane. Design loads for the runway beams, including connections and support brackets, of moving bridge cranes and monorail cranes shall include the maximum wheel loads of the crane and the vertical impact, lateral and longitudinal forces induced by the moving crane.
The maximum wheel loads shall be the wheel loads produced by the weight of the bridge, as applicable, plus the sum of the rated capacity and the weight of the trolley with the trolley positioned on its runway at the location where the resulting load effect is maximum.
The maximum wheel loads of the crane shall be increased by the following percentages to account for the effects of vertical impact or vibration:
| Monorail cranes (powered) | 25 percent |
| Cab-operated or remotely operated bridge cranes (powered) | 25 percent |
| Pendant-operated bridge cranes (powered) | 10 percent |
| Bridge cranes or monorail cranes with hand-geared bridge, trolley and hoist | 0 percent |
The lateral force on crane runway beams with electrically powered trolleys shall be calculated as 20 percent of the sum of the rated capacity of the crane and the weight of the hoist and trolley. The lateral force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction perpendicular to the beam, and shall be distributed with due regard to the lateral stiffness of the runway beam and supporting structure.
The longitudinal force on crane runway beams, except for bridge cranes with hand-geared bridges, shall be calculated as 10 percent of the maximum wheel loads of the crane. The longitudinal force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction parallel to the beam.
Interior walls and partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength and stiffness to resist the loads to which they are subjected but not less than a horizontal load of 5 psf (0.240 kN/m2). The 5 psf (0.24 kN/m2) allowable stress design load need not be applied simultaneously with wind or seismic loads. The deflection of such walls under a load of 5 psf (0.24 kN/m2) shall not exceed the limits in Table 1604A.3.
Fabric partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength and stiffness to resist the following load conditions:
- The horizontal distributed load need only be applied to the partition framing. The total area used to determine the distributed load shall be the area of the fabric face between the framing members to which the fabric is attached. The total distributed load shall be uniformly applied to such framing members in proportion to the length of each member.
- A concentrated load of 40 pounds (0.176 kN) applied to an 8-inch-diameter (203 mm) area [50.3 square inches (32 452 mm2)] of the fabric face at a height of 54 inches (1372 mm) above the floor.
In order to meet the structural stability requirements of Section 706.2 where the structure on either side of the wall has collapsed, fire walls and their supports shall be designed to withstand a minimum horizontal allowable stress load of 5 psf (0.240 kN/m2).
Fixed ladders with rungs shall be designed to resist a single concentrated load of 300 pounds (1.33 kN) in accordance with Section 4.5.4 of ASCE 7. Where rails of fixed ladders extend above a floor or platform at the top of the ladder, each side rail extension shall be designed to resist a single concentrated load of 100 pounds (0.445 kN) in accordance with Section 4.5.4 of ASCE 7. Ship's ladders shall be designed to resist the stair loads given in Table 1607A.1.
Bleachers, folding and telescopic seating and grandstands shall be designed for the loads specified in ICC 300 as modified by Section 1605A.3 load combinations. Stadiums and arenas with fixed seats shall be designed for the horizontal sway loads in Section 1607A.19.1.
The design of stadiums and arenas with fixed seats shall include horizontal swaying forces applied to each row of seats as follows:
- 24 pounds per linear foot (0.35 kN/m) of seat applied in a direction parallel to each row of seats.
- 10 pounds per linear foot (0.15 kN/m) of seat applied in a direction perpendicular to each row of seats.
The parallel and perpendicular horizontal swaying forces are not required to be applied simultaneously.
The live loads indicated in Table 1607A.1 for attics in residential occupancies shall comply with the requirements of this section.
In residential occupancies, uninhabitable attic areas without storage are those where the maximum clear height between the joists and rafters is less than 42 inches (1067 mm), or where there are not two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches (1067 mm) in height by 24 inches (610 mm) in width, or greater, within the plane of the trusses. The live load in Table 1607A.1 need not be assumed to act concurrently with any other live load requirement.
In residential occupancies, uninhabitable attic areas with storage are those where the maximum clear height between the joist and rafter is 42 inches (1067 mm) or greater, or where there are two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches (1067 mm) in height by 24 inches (610 mm) in width, or greater, within the plane of the trusses. The live load in Table 1607A.1 need only be applied to those portions of the joists or truss bottom chords where both of the following conditions are met:
- The attic area is accessed from an opening not less than 20 inches (508 mm) in width by 30 inches (762 mm) in length that is located where the clear height in the attic is not less than 30 inches (762 mm).
- The slope of the joists or truss bottom chords is not greater than 2 units vertical in 12 units horizontal.
The remaining portions of the joists or truss bottom chords shall be designed for a uniformly distributed concurrent live load of not less than 10 pounds per square foot (0.48 kN/m2).
Design snow loads shall be determined in accordance with Chapter 7 of ASCE 7, but the design roof load shall be not less than that determined by Section 1607A.
The ground snow loads to be used in determining the design snow loads for roofs shall be determined in accordance with ASCE 7 or Figures 1608A.2(1) and 1608A.2(2) for the contiguous United States. Site-specific case studies shall be made in areas designated "CS" in Figures 1608A.2(1) and 1608A.2(2). Ground snow loads for sites at elevations above the limits indicated in Figures 1608A.2(1) and 1608A.2(2) and for all sites within the CS areas shall be approved. Ground snow load determination for such sites shall be based on an extreme value statistical analysis of data available in the vicinity of the site using a value with a 2-percent annual probability of being exceeded (50-year mean recurrence interval).
NOTE: See ASCE 7 Table 7.2-2 for Colorado, Table 7.2-3 for Idaho, Table 7.2-4 for Montana, Table 7.2-5 for Washington, Table 7.2-6 for New Mexico and Table 7.2-7 for Oregon.
FIGURE 1608A.2(1)
GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)
NOTE: See ASCE 7 Table 7.2-8 for New Hampshire.
FIGURE 1608A.2(2)
GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)
Susceptible bays of roofs shall be evaluated for ponding instability in accordance with Chapters 7 and 8 of ASCE 7.
[DSA-SS] The ground snow load or the design snow load for roofs shall conform with the adopted ordinance of the city, county, or city and county in which the project site is located, and shall be approved by DSA. See Section 106.1.2 for snow load posting requirements.
Buildings, structures and parts thereof shall be designed to withstand the minimum wind loads prescribed herein. Decreases in wind loads shall not be made for the effect of shielding by other structures.
Wind loads on every building or structure shall be determined in accordance with Chapters 26 to 30 of ASCE 7. The type of opening protection required, the basic design wind speed, V, and the exposure category for a site is permitted to be determined in accordance with Section 1609A or ASCE 7. Wind shall be assumed to come from any horizontal direction and wind pressures shall be assumed to act normal to the surface considered.
Exceptions:
- Subject to the limitations of Section 1609A.1.1.1, the provisions of ICC 600 shall be permitted for applicable Group R-2 and R-3 buildings.
- Subject to the limitations of Section 1609A.1.1.1, residential structures using the provisions of AWC WFCM.
- Subject to the limitations of Section 1609A.1.1.1, residential structures using the provisions of AISI S230.
- Designs using NAAMM FP 1001.
- Designs using TIA-222 for antenna-supporting structures and antennas, provided that the horizontal extent of Topographic Category 2 escarpments in Section 2.6.6.2 of TIA-222 shall be 16 times the height of the escarpment.
- Wind tunnel tests in accordance with ASCE 49 and Sections 31.4 and 31.5 of ASCE 7.
The wind speeds in Figures 1609A.3(1) through 1609A.3(12) are basic design wind speeds, V, and shall be converted in accordance with Section 1609A.3.1 to allowable stress design wind speeds, Vasd, when the provisions of the standards referenced in Exceptions 4 and 5 are used.
The provisions of ICC 600 are applicable only to buildings located within Exposure B or C as defined in Section 1609A.4. The provisions of ICC 600, AWC WFCM and AISI S230 shall not apply to buildings sited on the upper half of an isolated hill, ridge or escarpment meeting all of the following conditions:
- The hill, ridge or escarpment is 60 feet (18 288 mm) or higher if located in Exposure B or 30 feet (9144 mm) or higher if located in Exposure C.
- The maximum average slope of the hill exceeds 10 percent.
- The hill, ridge or escarpment is unobstructed upwind by other such topographic features for a distance from the high point of 50 times the height of the hill or 2 miles (3.22 km), whichever is greater.
The calculated story drift due to wind pressures with ultimate design wind speed, Vult , shall not exceed 0.008 times the story height for buildings less than 65 feet (19812 mm) in height or 0.007 times the story height for buildings 65 feet (19812 mm) or greater in height.
Exception: [DSA-SS] This story drift limit need not be applied for single-story open structures in Risk Categories I and II.
In windborne debris regions, glazing in buildings shall be impact resistant or protected with an impact-resistant covering meeting the requirements of an approved impact-resistant standard or ASTM E1996 referenced herein as follows:
- Glazed openings located within 30 feet (9144 mm) of grade shall meet the requirements of the large missile test of ASTM E1996.
- Glazed openings located more than 30 feet (9144 mm) above grade shall meet the provisions of the small missile test of ASTM E1996.
Exceptions:
- Wood structural panels with a minimum thickness of 7/16 inch (11.1 mm) and maximum panel span of 8 feet (2438 mm) shall be permitted for opening protection in buildings with a mean roof height of 33 feet (10 058 mm) or less that are classified as a Group R-3 or R-4 occupancy. Panels shall be precut so that they shall be attached to the framing surrounding the opening containing the product with the glazed opening. Panels shall be predrilled as required for the anchorage method and shall be secured with the attachment hardware provided. Attachments shall be designed to resist the components and cladding loads determined in accordance with the provisions of ASCE 7, with corrosion-resistant attachment hardware provided and anchors permanently installed on the building. Attachment in accordance with Table 1609A.2 with corrosion-resistant attachment hardware provided and anchors permanently installed on the building is permitted for buildings with a mean roof height of 45 feet (13 716 mm) or less where Vasd determined in accordance with Section 1609A.3.1 does not exceed 140 mph (63 m/s).
- Glazing in Risk Category I buildings, including greenhouses that are occupied for growing plants on a production or research basis, without public access shall be permitted to be unprotected.
- Glazing in Risk Category II, III or IV buildings located over 60 feet (18 288 mm) above the ground and over 30 feet (9144 mm) above aggregate surface roofs located within 1,500 feet (458 m) of the building shall be permitted to be unprotected.
TABLE 1609A.2
WINDBORNE DEBRIS PROTECTION FASTENING SCHEDULE FOR WOOD STRUCTURAL PANELSa, b, c, d
| FASTENER TYPE | FASTENER SPACING (inches) | ||
| Panel Span ≤ 4 feet | 4 feet < Panel Span ≤ 6 feet | 6 feet < Panel Span ≤ 8 feet | |
| No. 8 wood-screw-based anchor with 2-inch embedment length | 16 | 10 | 8 |
| No. 10 wood-screw-based anchor with 2-inch embedment length | 16 | 12 | 9 |
| 1/4-inch diameter lag-screw-based anchor with 2-inch embedment length | 16 | 16 | 16 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N, 1 mile per hour = 0.447 m/s.
- This table is based on 140 mph wind speeds and a 45-foot mean roof height.
- Fasteners shall be installed at opposing ends of the wood structural panel. Fasteners shall be located not less than 1 inch from the edge of the panel.
- Anchors shall penetrate through the exterior wall covering with an embedment length of 2 inches minimum into the building frame. Fasteners shall be located not less than 21/2 inches from the edge of concrete block or concrete.
- Where panels are attached to masonry or masonry/stucco, they shall be attached using vibration-resistant anchors having a minimum ultimate withdrawal capacity of 1,500 pounds.
Louvers protecting intake and exhaust ventilation ducts not assumed to be open that are located within 30 feet (9144 mm) of grade shall meet the requirements of AMCA 540.
The text of Section 6.2.2 of ASTM E1996 shall be substituted as follows:
6.2.2 Unless otherwise specified, select the wind zone based on the basic design wind speed, V, as follows:
6.2.2.1 Wind Zone 1—130 mph ≤ basic design wind speed, V < 140 mph.
6.2.2.2 Wind Zone 2—140 mph ≤ basic design wind speed, V < 150 mph at greater than one mile (1.6 km) from the coastline. The coastline shall be measured from the mean high water mark.
6.2.2.3 Wind Zone 3—150 mph (67 m/s) ≤ basic design wind speed, V ≤ 160 mph (72 m/s), or 140 mph (63 m/s) ≤ basic design wind speed, V ≤ 160 mph (72 m/s) and within one mile (1.6 km) of the coastline. The coastline shall be measured from the mean high water mark.
6.2.2.4 Wind Zone 4— basic design wind speed, V > 160 mph (72 m/s).
The basic design wind speed, V, in mph, for the determination of the wind loads shall be determined by Figures 1609A.3(1) through 1609A.3(12). The basic design wind speed, V, for use in the design of Risk Category II buildings and structures shall be obtained from Figures 1609A.3(1), 1609A.3(5) and 1609A.3(6). The basic design wind speed, V, for use in the design of Risk Category III buildings and structures shall be obtained from Figures 1609A.3(2), 1609A.3(7) and 1609A.3(8). The basic design wind speed, V, for use in the design of Risk Category IV buildings and structures shall be obtained from Figures 1609A.3(3), 1609A.3(9) and 1609A.3(10). The basic design wind speed, V, for use in the design of Risk Category I buildings and structures shall be obtained from Figures 1609A.3(4), 1609A.3(11) and 1609A.3(12). The basic design wind speed, V, for the special wind regions indicated near mountainous terrain and near gorges shall be in accordance with local jurisdiction requirements. The basic design wind speeds, V, determined by the local jurisdiction shall be in accordance with Chapter 26 of ASCE 7.
In nonhurricane-prone regions, when the basic design wind speed, V, is estimated from regional climatic data, the basic design wind speed, V, shall be determined in accordance with Chapter 26 of ASCE 7.
Notes:
- Values are nominal design 3-second gust wind speeds in miles per hour (m/s) at 33 feet (10 m) above ground for Exposure C Category.
- Linear interpolation between contours. Point values are provided to aid with interpolation.
- Islands, coastal areas, and land boundaries outside the last contour shall use the last wind speed contour.
- Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions.
- Wind speeds correspond to approximately a 7% probability of exceedance in 50 years (Annual Exceedance Probability = 0.00143, MRI = 700 Years).
- Location-specific basic wind speeds shall be permitted to be determined using www.atcouncil.org/windspeed
FIGURE 1609A.3(1)
Notes:
- Values are nominal design 3-second gust wind speeds in miles per hour (m/s) at 33 feet (10 m) above ground for Exposure C Category.
- Linear interpolation between contours. Point values are provided to aid with interpolation.
- Islands, coastal areas, and land boundaries outside the last contour shall use the last wind speed contour.
- Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions.
- Wind speeds correspond to approximately a 3% probability of exceedance in 50 years (Annual Exceedance Probability = 0.000588, MRI = 1700 Years).
- Location-specific basic wind speeds shall be permitted to be determined using www.atcouncil.org/windspeed
FIGURE 1609A.3(2)
Notes:
- Values are nominal design 3-second gust wind speeds in miles per hour (m/s) at 33 feet (10 m) above ground for Exposure C Category.
- Linear interpolation between contours. Point values are provided to aid with interpolation.
- Islands, coastal areas, and land boundaries outside the last contour shall use the last wind speed contour.
- Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions.
- Wind speeds correspond to approximately a 1.6% probability of exceedance in 50 years (Annual Exceedance Probability = 0.00033, MRI = 3000 Years).
- Location-specific basic wind speeds shall be permitted to be determined using www.atcouncil.org/windspeed
FIGURE 1609A.3(3)
Notes:
- Values are nominal design 3-second gust wind speeds in miles per hour (m/s) at 33 feet (10 m) above ground for Exposure C Category.
- Linear interpolation between contours. Point values are provided to aid with interpolation.
- Islands, coastal areas, and land boundaries outside the last contour shall use the last wind speed contour.
- Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions.
- Wind speeds correspond to approximately a 15% probability of exceedance in 50 years (Annual Exceedance Probability = 0.00333, MRI = 300 Years).
- Location-specific basic wind speeds shall be permitted to be determined using www.atcouncil.org/windspeed.
FIGURE 1609A.3(4)
Where required, the basic design wind speeds of Figures 1609A.3(1) through 1609A.3(12) shall be converted to allowable stress design wind speeds, Vasd, using Table 1609A.3.1 or Equation 16-17.
(Equation 16A-17)
Vasd = Allowable stress design wind speed applicable to methods specified in Exceptions 4 and 5 of Section 1609A.1.1.
TABLE 1609A.3.1
WIND SPEED CONVERSIONSa, b, c
| V | 100 | 110 | 120 | 130 | 140 | 150 | 160 | 170 | 180 | 190 | 200 |
| Vasd | 78 | 85 | 93 | 101 | 108 | 116 | 124 | 132 | 139 | 147 | 155 |
For SI: 1 mile per hour = 0.44 m/s.
- Linear interpolation is permitted.
- Vasd = allowable stress design wind speed applicable to methods specified in Exceptions 1 through 5 of Section 1609A.1.1.
- V = basic design wind speeds determined from Figures 1609A.3(1) through 1609A.3(12).
For each wind direction considered, an exposure category that adequately reflects the characteristics of ground surface irregularities shall be determined for the site at which the building or structure is to be constructed. Account shall be taken of variations in ground surface roughness that arise from natural topography and vegetation as well as from constructed features.
For each selected wind direction at which the wind loads are to be evaluated, the exposure of the building or structure shall be determined for the two upwind sectors extending 45 degrees (0.79 rad) either side of the selected wind direction. The exposures in these two sectors shall be determined in accordance with Sections 1609A.4.2 and 1609.4.3 and the exposure resulting in the highest wind loads shall be used to represent winds from that direction.
A ground surface roughness within each 45-degree (0.79 rad) sector shall be determined for a distance upwind of the site as defined in Section 1609A.4.3 from the following categories, for the purpose of assigning an exposure category as defined in Section 1609A.4.3.
- Surface Roughness B. Urban and suburban areas, wooded areas or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger.
- Surface Roughness C. Open terrain with scattered obstructions having heights generally less than 30 feet (9144 mm). This category includes flat open country, and grasslands.
- Surface Roughness D. Flat, unobstructed areas and water surfaces. This category includes smooth mud flats, salt flats and unbroken ice.
An exposure category shall be determined in accordance with the following:
Exposure B. For buildings with a mean roof height of less than or equal to 30 feet (9144 mm), Exposure B shall apply where the ground surface roughness, as defined by Surface Roughness B, prevails in the upwind direction for a distance of not less than 1,500 feet (457 m). For buildings with a mean roof height greater than 30 feet (9144 mm), Exposure B shall apply where Surface Roughness B prevails in the upwind direction for a distance of not less than 2,600 feet (792 m) or 20 times the height of the building, whichever is greater.
Exposure C. Exposure C shall apply for all cases where Exposure B or D does not apply.
Exposure D. Exposure D shall apply where the ground surface roughness, as defined by Surface Roughness D, prevails in the upwind direction for a distance of not less than 5,000 feet (1524 m) or 20 times the height of the building, whichever is greater. Exposure D shall apply where the ground surface roughness immediately upwind of the site is B or C, and the site is within a distance of 600 feet (183 m) or 20 times the building height, whichever is greater, from an Exposure D condition as defined in the previous sentence.
The roof deck shall be designed to withstand the wind pressures determined in accordance with ASCE 7.
Roof coverings shall comply with Section 1609A.5.1.
Exception: Rigid tile roof coverings that are air permeable and installed over a roof deck complying with Section 1609A.5.1 are permitted to be designed in accordance with Section 1609A.5.3.
Asphalt shingles installed over a roof deck complying with Section 1609A.5.1 shall comply with the wind-resistance requirements of Section 1504.2.
Wind loads on rigid tile roof coverings shall be determined in accordance with the following equation:
(Equation 16A-18)
For SI:
b = Exposed width, feet (mm) of the roof tile.
CL = Lift coefficient. The lift coefficient for concrete and clay tile shall be 0.2 or shall be determined by test in accordance with Section 1504.3.1.
GCp = Roof pressure coefficient for each applicable roof zone determined from Chapter 30 of ASCE 7. Roof coefficients shall not be adjusted for internal pressure.
L = Length, feet (mm) of the roof tile.
La = Moment arm, feet (mm) from the axis of rotation to the point of uplift on the roof tile. The point of uplift shall be taken at 0.76L from the head of the tile and the middle of the exposed width. For roof tiles with nails or screws (with or without a tail clip), the axis of rotation shall be taken as the head of the tile for direct deck application or as the top edge of the batten for battened applications. For roof tiles fastened only by a nail or screw along the side of the tile, the axis of rotation shall be determined by testing. For roof tiles installed with battens and fastened only by a clip near the tail of the tile, the moment arm shall be determined about the top edge of the batten with consideration given for the point of rotation of the tiles based on straight bond or broken bond and the tile profile.
Ma = Aerodynamic uplift moment, feet-pounds (N-mm) acting to raise the tail of the tile.
qh = Wind velocity pressure, psf (kN/m2) determined from Section 26.10.2 of ASCE 7.
Concrete and clay roof tiles complying with the following limitations shall be designed to withstand the aerodynamic uplift moment as determined by this section.
- The roof tiles shall be either loose laid on battens, mechanically fastened, mortar set or adhesive set.
- The roof tiles shall be installed on solid sheathing that has been designed as components and cladding.
- An underlayment shall be installed in accordance with Chapter 15.
- The tile shall be single lapped interlocking with a minimum head lap of not less than 2 inches (51 mm).
- The length of the tile shall be between 1.0 and 1.75 feet (305 mm and 533 mm).
- The exposed width of the tile shall be between 0.67 and 1.25 feet (204 mm and 381 mm).
- The maximum thickness of the tail of the tile shall not exceed 1.3 inches (33 mm).
- Roof tiles using mortar set or adhesive set systems shall have not less than two-thirds of the tile's area free of mortar or adhesive contact.
Foundation walls and retaining walls shall be designed to resist lateral soil loads from adjacent soil. Soil loads specified in Table 1610A.1 shall be used as the minimum design lateral soil loads unless determined otherwise by a geotechnical investigation in accordance with Section 1803A. Foundation walls and other walls in which horizontal movement is restricted at the top shall be designed for at-rest pressure. Retaining walls free to move and rotate at the top shall be permitted to be designed for active pressure. Lateral pressure from surcharge loads shall be added to the lateral soil load. Lateral pressure shall be increased if expansive soils are present at the site. Foundation walls shall be designed to support the weight of the full hydrostatic pressure of undrained backfill unless a drainage system is installed in accordance with Sections 1805A.4.2 and 1805A.4.3.
Exception: Foundation walls extending not more than 8 feet (2438 mm) below grade and laterally supported at the top by flexible diaphragms shall be permitted to be designed for active pressure.
TABLE 1610A.1
LATERAL SOIL LOAD
| DESCRIPTION OF BACKFILL MATERIALc | UNIFIED SOIL CLASSIFICATION | DESIGN LATERAL SOIL LOADa (pound per square foot per foot of depth) | |
| Active pressure | At-rest pressure | ||
| Well-graded, clean gravels; gravel-sand mixes | GW | 30 | 60 |
| Poorly graded clean gravels; gravel-sand mixes | GP | 30 | 60 |
| Silty gravels, poorly graded gravel-sand mixes | GM | 40 | 60 |
| Clayey gravels, poorly graded gravel-and-clay mixes | GC | 45 | 60 |
| Well-graded, clean sands; gravelly sand mixes | SW | 30 | 60 |
| Poorly graded clean sands; sand-gravel mixes | SP | 30 | 60 |
| Silty sands, poorly graded sand-silt mixes | SM | 45 | 60 |
| Sand-silt clay mix with plastic fines | SM-SC | 45 | 100 |
| Clayey sands, poorly graded sand-clay mixes | SC | 60 | 100 |
| Inorganic silts and clayey silts | ML | 45 | 100 |
| Mixture of inorganic silt and clay | ML-CL | 60 | 100 |
| Inorganic clays of low to medium plasticity | CL | 60 | 100 |
| Organic silts and silt clays, low plasticity | OL | Note b | Note b |
| Inorganic clayey silts, elastic silts | MH | Note b | Note b |
| Inorganic clays of high plasticity | CH | Note b | Note b |
| Organic clays and silty clays | OH | Note b | Note b |
For SI: 1 pound per square foot per foot of depth = 0.157 kPa/m, 1 foot = 304.8 mm.
- Design lateral soil loads are given for moist conditions for the specified soils at their optimum densities. Actual field conditions shall govern. Submerged or saturated soil pressures shall include the weight of the buoyant soil plus the hydrostatic loads.
- Unsuitable as backfill material.
- The definition and classification of soil materials shall be in accordance with ASTM D2487.
Basement floors, slabs on ground, foundations, and similar approximately horizontal elements below grade shall be designed to resist uplift loads where applicable. The upward pressure of water shall be taken as the full hydrostatic pressure applied over the entire area. The hydrostatic load shall be measured from the underside of the element being evaluated. The design for upward loads caused by expansive soils shall comply with Section 1808A.6.
Each portion of a roof shall be designed to sustain the load of rainwater as per the requirements of Chapter 8 of ASCE 7. The design rainfall shall be based on the 100-year 15-minute duration event, or on other rainfall rates determined from approved local weather data. Alternatively, a design rainfall of twice the 100-year hourly rainfall rate indicated in Figures 1611A.1(1) through 1611A.1(5) shall be permitted.
(Equation 16A-19) 
dh = Additional depth of water on the undeflected roof above the inlet of secondary drainage system at its design flow (in other words, the hydraulic head), in inches (mm).
ds = Depth of water on the undeflected roof up to the inlet of secondary drainage system when the primary drainage system is blocked (in other words, the static head), in inches (mm).
R = Rain load on the undeflected roof, in psf (kN/m2). Where the phrase "undeflected roof" is used, deflections from loads (including dead loads) shall not be considered when determining the amount of rain on the roof.
For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.
FIGURE 1611A.1(1)
100-YEAR, 1-HOUR RAINFALL (INCHES) WESTERN UNITED STATES
100-YEAR, 1-HOUR RAINFALL (INCHES) WESTERN UNITED STATES
For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.
FIGURE 1611A.1(2)
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.
FIGURE 1611A.1(3)
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.
FIGURE 1611A.1(4)
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.
FIGURE 1611A.1(5)
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
Susceptible bays of roofs shall be evaluated for ponding instability in accordance with Chapters 7 and 8 of ASCE 7.
Roofs equipped with hardware to control the rate of drainage shall be equipped with a secondary drainage system at a higher elevation that limits accumulation of water on the roof above that elevation. Such roofs shall be designed to sustain the load of rainwater that will accumulate on them to the elevation of the secondary drainage system plus the uniform load caused by water that rises above the inlet of the secondary drainage system at its design flow determined from Section 1611A.1. Such roofs shall be checked for ponding instability in accordance with Section 1611A.2.
Within flood hazard areas as established in Section 1612A.3, all new construction of buildings, structures and portions of buildings and structures, including substantial improvement and restoration of substantial damage to buildings and structures, shall be designed and constructed to resist the effects of flood hazards and flood loads. For buildings that are located in more than one flood hazard area, the provisions associated with the most restrictive flood hazard area shall apply.
The design and construction of buildings and structures located in flood hazard areas, including coastal high hazard areas and coastal A zones, shall be in accordance with Chapter 5 of ASCE 7 and ASCE 24.
To establish flood hazard areas, the applicable governing authority shall adopt a flood hazard map and supporting data. The flood hazard map shall include, at a minimum, areas of special flood hazard as identified by the Federal Emergency Management Agency's Flood Insurance Study (FIS) adopted by the local authority having jurisdiction where the project is located, as amended or revised with the accompanying Flood Insurance Rate Map (FIRM) and Flood Boundary and Floodway Map (FBFM) and related supporting data along with any revisions thereto. The adopted flood hazard map and supporting data are hereby adopted by reference and declared to be part of this section.
Where design flood elevations are not included in the flood hazard areas established in Section 1612A.3, or where floodways are not designated, the building official is authorized to require the applicant to do one of the following:
- Obtain and reasonably utilize any design flood elevation and floodway data available from a federal, state or other source.
- Determine the design flood elevation or floodway in accordance with accepted hydrologic and hydraulic engineering practices used to define special flood hazard areas. Determinations shall be undertaken by a registered design professional who shall document that the technical methods used reflect currently accepted engineering practice.
In riverine flood hazard areas where design flood elevations are specified but floodways have not been designated, the applicant shall provide a floodway analysis that demonstrates that the proposed work will not increase the design flood elevation more than 1 foot (305 mm) at any point within the jurisdiction of the applicable governing authority.
The following documentation shall be prepared and sealed by a registered design professional and submitted to the building official:
-
For construction in flood hazard areas other than coastal high hazard areas or coastal A zones:
- The elevation of the lowest floor, including the basement, as required by the lowest floor elevation inspection in Section 110.3.3 and for the final inspection in Section 110.3.12.1.
- For fully enclosed areas below the design flood elevation where provisions to allow for the automatic entry and exit of floodwaters do not meet the minimum requirements in Section 2.7.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.7.2.2 of ASCE 24.
- For dry floodproofed nonresidential buildings, construction documents shall include a statement that the dry floodproofing is designed in accordance with ASCE 24 and shall include the flood emergency plan specified in Chapter 6 of ASCE 24.
-
For construction in coastal high hazard areas and coastal A zones:
- The elevation of the bottom of the lowest horizontal structural member as required by the lowest floor elevation inspection in Section 110.3.3 and for the final inspection in Section 110.3.12.1.
- Construction documents shall include a statement that the building is designed in accordance with ASCE 24, including that the pile or column foundation and building or structure to be attached thereto is designed to be anchored to resist flotation, collapse and lateral movement due to the effects of wind and flood loads acting simultaneously on all building components, and other load requirements of Chapter 16.
- For breakaway walls designed to have a resistance of more than 20 psf (0.96 kN/m2) determined using allowable stress design, construction documents shall include a statement that the breakaway wall is designed in accordance with ASCE 24.
- For breakaway walls where provisions to allow for the automatic entry and exit of floodwaters do not meet the minimum requirements in Section 2.7.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.7.2.2 of ASCE 24.
Every structure, and portion thereof, including nonstructural components that are permanently attached to structures and their supports and attachments, shall be designed and constructed to resist the effects of earthquake motions in accordance with Chapters 11, 12, 13, 15, 17 and 18 of ASCE 7, as applicable. The seismic design category for a structure shall be determined in accordance with Section 1613A.
Seismic ground motion values shall be determined in accordance with this section.
Based on the site soil properties, the site shall be classified as Site Class A, B, C, D, E or F in accordance with Chapter 20 of ASCE 7.
Where the soil properties are not known in sufficient detail to determine the site class, Site Class D, subjected to the requirements of Section 1613A.2.3, shall be used unless the building official or geotechnical data determines that Site Class E or F soils are present at the site.
Where site investigations that are performed in accordance with Chapter 20 of ASCE 7 reveal rock conditions consistent with Site Class B, but site-specific velocity measurements are not made, the site coefficients Fa and Fv shall be taken at unity (1.0).
The maximum considered earthquake spectral response acceleration for short periods, SMS, and at 1-second period, SM1, adjusted for site class effects shall be determined by Equations 16A-20 and 16-21, respectively:
(Equation 16A-20) 
(Equation 16A-21) but SMS shall not be taken less than SM1 except when determining the seismic design category in accordance with Section 1613A.2.5.
SS = The mapped spectral accelerations for short periods as determined in Section 1613A.2.1.
S1 = The mapped spectral accelerations for a 1-second period as determined in Section 1613A.2.1.
Where Site Class D is selected as the default site class per Section 1613A.2.2, the value of Fa shall be not less than 1.2.
| SITE CLASS | MAPPED RISK TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER)
SPECTRAL RESPONSE ACCELERATION PARAMETER AT SHORT PERIOD
|
|||||
| Ss ≤ 0.25 | Ss = 0.50 | Ss = 0.75 | Ss = 1.00 | Ss = 1.25 | Ss ≥ 1.5 | |
| A | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
| B | 0.9 | 0.9 | 0.9 | 0.9 | 0.9 | 0.9 |
| C | 1.3 | 1.3 | 1.2 | 1.2 | 1.2 | 1.2 |
| D | 1.6 | 1.4 | 1.2 | 1.1 | 1.0 | 1.0 |
| E | 2.4 | 1.7 | 1.3 | 1.2 c | 1.2 c | 1.2 c |
| F | Note b | Note b | Note b | Note b | Note b | Note b |
- Use straight-line interpolation for intermediate values of mapped spectral response acceleration at short period, Ss.
- Values shall be determined in accordance with Section 11.4.8 of ASCE 7.
- See requirements for site-specific ground motions in Section 11.4.8 of ASCE 7. These values of Fa shall only be used for calculation of Ts, determination of Seismic Design Category, linear interpolation for intermediate values of Ss, and when taking the exception under Item 2 within Section 11.4.8 of ASCE 7.
| SITE CLASS | MAPPED RISK TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER)
SPECTRAL RESPONSE ACCELERATION PARAMETER AT 1-SECOND PERIOD
|
|||||
| S1 ≤ 0.1 | S1 = 0.2 | S1 = 0.3 | S1 = 0.4 | S1 = 0.5 | S1 ≥ 0.6 | |
| A | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
| B | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
| C | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 | 1.4 |
| D | 2.4 | 2.2c | 2.0c | 1.9c | 1.8c | 1.7c |
| E | 4.2 | 3.3c | 2.8c | 2.4c | 2.2c | 2.0c |
| F | Note b | Note b | Note b | Note b | Note b | Note b |
- Use straight-line interpolation for intermediate values of mapped spectral response acceleration at 1-second period, S1.
- Values shall be determined in accordance with Section 11.4.8 of ASCE 7.
- See requirements for site-specific ground motions in Section 11.4.8 of ASCE 7. These values of Fv shall only be used for calculation of Ts, determination of Seismic Design Category, linear interpolation for intermediate values of S1, and when taking the exceptions under Items 1 and 2 of Section 11.4.8 for the calculation of SD1.
Five-percent damped design spectral response acceleration at short periods, SDS, and at 1-second period, SD1, shall be determined from Equations 16-22 and Equation 16-23, respectively:
(Equation 16A-22)
(Equation 16A-23)
SMS = The maximum considered earthquake spectral response accelerations for short period as determined in Section 1613A.2.3.
SM1 = The maximum considered earthquake spectral response accelerations for 1-second period as determined in Section 1613A.2.3.
Structures classified as Risk Category I, II or III that are located where the mapped spectral response acceleration parameter at 1-second period, S1, is greater than or equal to 0.75 shall be assigned to Seismic Design Category E. Structures classified as Risk Category IV that are located where the mapped spectral response acceleration parameter at 1-second period, S1, is greater than or equal to 0.75 shall be assigned to Seismic Design Category F. Other structures shall be assigned to Seismic Design Category D.
Not permitted by DSA-SS and OSHPD.
Not permitted by DSA-SS and OSHPD.
Ballasted, roof-mounted photovoltaic panel systems need not be rigidly attached to the roof or supporting structure.
[DSA-SS] Ballasted, roof-mounted photovoltaic panel systems shall comply with ASCE 7 13.6.12.
Ice-sensitive structures shall be designed for atmospheric ice loads in accordance with Chapter 10 of ASCE 7.
The design and construction of Risk Category III and IV buildings and structures located in the Tsunami Design Zones defined in the ASCE Tsunami Design Geodatabase, or other data determined applicable by the enforcement agency, shall be in accordance with Chapter 6 of ASCE 7, except as modified by this code. [DSA-SS] Tsunami Risk Category for public school, community college and state-owned or state-leased essential services buildings and structures shall be identified and submitted for acceptance by DSA. Determination of the Tsunami Risk Category shall be proposed by the design professional in general responsible charge in coordination with the owner and local community based upon the relative importance of that facility to provide vital services, provide important functions and protect special populations. The determination of relative importance shall include consideration of a tsunami warning and evacuation plan and procedure when adopted by the local community.
High-rise buildings that are assigned to Risk Category III or IV shall comply with the requirements of Section 1616A.2 if they are frame structures, or Section 1616A.3 if they are bearing wall structures.
Frame structures shall comply with the requirements of this section.
Frame structures constructed primarily of reinforced or prestressed concrete, either cast-in-place or precast, or a combination of these, shall conform to the requirements of Section 4.10 of ACI 318. Where ACI 318 requires that nonprestressed reinforcing or prestressing steel pass through the region bounded by the longitudinal column reinforcement, that reinforcing or prestressing steel shall have a minimum nominal tensile strength equal to two-thirds of the required one-way vertical strength of the connection of the floor or roof system to the column in each direction of beam or slab reinforcement passing through the column.
Exception: Where concrete slabs with continuous reinforcement having an area not less than 0.0015 times the concrete area in each of two orthogonal directions are present and are either monolithic with or equivalently bonded to beams, girders or columns, the longitudinal reinforcing or prestressing steel passing through the column reinforcement shall have a nominal tensile strength of one-third of the required one-way vertical strength of the connection of the floor or roof system to the column in each direction of beam or slab reinforcement passing through the column.
Frame structures constructed with a structural steel frame or a frame composed of open web steel joists, joist girders with or without other structural steel elements or a frame composed of composite steel or composite steel joists and reinforced concrete elements shall conform to the requirements of this section.
End connections of all beams and girders shall have a minimum nominal axial tensile strength equal to the required vertical shear strength for allowable stress design (ASD) or two-thirds of the required shear strength for load and resistance factor design (LRFD) but not less than 10 kips (45 kN). For the purpose of this section, the shear force and the axial tensile force need not be considered to act simultaneously.
Exception: Where beams, girders, open web joist and joist girders support a concrete slab or concrete slab on metal deck that is attached to the beam or girder with not less than 3/8-inch-diameter (9.5 mm) headed shear studs, at a spacing of not more than 12 inches (305 mm) on center, averaged over the length of the member, or other attachment having equivalent shear strength, and the slab contains continuous distributed reinforcement in each of two orthogonal directions with an area not less than 0.0015 times the concrete area, the nominal axial tension strength of the end connection shall be permitted to be taken as half the required vertical shear strength for ASD or one-third of the required shear strength for LRFD, but not less than 10 kips (45 kN).
Bearing wall structures shall have vertical ties in all load-bearing walls and longitudinal ties, transverse ties and perimeter ties at each floor level in accordance with this section and as shown in Figure 1616A.3.
FIGURE 1616A.3
LONGITUDINAL, PERIMETER, TRANSVERSE AND VERTICAL TIES
Precast bearing wall structures constructed solely of reinforced or prestressed concrete, or combinations of these shall conform to the requirements of Sections 16.2.4 and 16.2.5 of ACI 318.
Ties in bearing wall structures other than those covered in Section 1616A.3.1 shall conform to this section.
Longitudinal ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Longitudinal ties shall extend across interior load-bearing walls and shall connect to exterior load-bearing walls and shall be spaced at not greater than 10 feet (3038 mm) on center. Ties shall have a minimum nominal tensile strength, TT, given by Equation 16A-24. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.
(Equation 16A-24)
L = The span of the horizontal element in the direction of the tie, between bearing walls, feet (m).
w = The weight per unit area of the floor or roof in the span being tied to or across the wall, psf (N/m2).
S = The spacing between ties, feet (m).
αT = A coefficient with a value of 1,500 pounds per foot (2.25 kN/m) for masonry bearing wall structures and a value of 375 pounds per foot (0.6 kN/m) for structures with bearing walls of cold-formed steel light-frame construction.
Transverse ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Transverse ties shall be placed not farther apart than the spacing of load-bearing walls. Transverse ties shall have minimum nominal tensile strength TT, given by Equation 16A-24. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.
Perimeter ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Ties around the perimeter of each floor and roof shall be located within 4 feet (1219 mm) of the edge and shall provide a nominal strength in tension not less than Tp, given by Equation 16A-25. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.
(Equation 16A-25)
w = As defined in Section 1616A.3.2.1.
βT = A coefficient with a value of 16,000 pounds (7200 kN) for structures with masonry bearing walls and a value of 4,000 pounds (1300 kN) for structures with bearing walls of cold-formed steel light-frame construction.
Vertical ties shall consist of continuous or spliced reinforcing, continuous or spliced members, wall sheathing or other engineered systems. Vertical tension ties shall be provided in bearing walls and shall be continuous over the height of the building. The minimum nominal tensile strength for vertical ties within a bearing wall shall be equal to the weight of the wall within that story plus the weight of the diaphragm tributary to the wall in the story below. Not fewer than two ties shall be provided for each wall. The strength of each tie need not exceed 3,000 pounds per foot (450 kN/m) of wall tributary to the tie for walls of masonry construction or 750 pounds per foot (140 kN/m) of wall tributary to the tie for walls of cold-formed steel light-frame construction.
The text of ASCE 7 shall be modified as indicated in Sections 1617A.1.1 through 1617A.1.40.
Modify ASCE 7, Section 1.3 by adding Section 1.3.8 as follows:
1.3.8 Structural design criteria. Where design is based on ASCE 7, Chapters 16, 17 or 18, the ground motion, analysis and design methods, material assumptions, testing requirements and acceptance criteria proposed by the engineer shall be submitted to the enforcement agency in the form of structural design criteria for approval. [DSA-SS] Structural design criteria including wind tunnel design recommendations are required where design is based on ASCE 7, Chapter 31.
[DSA-SS] Peer review requirements in Section 322 of the California Existing Building Code shall apply to design reviews required by ASCE 7, Chapters 17 and 18.
[OSHPD 1 & 4] Peer review requirements in Section 1617A.1.41 of this code shall apply to design reviews required by ASCE 7, Chapters 17 and 18.
Replace last paragraph of ASCE 7, Section 11.1.3, by the following:
Non-building structures similar to buildings shall be designed and detailed in accordance with Chapter 12.
Modify ASCE 7, Section 11.4 to include the following:
Seismic ground motion values shall include updated subsections in Supplement 3. [OSHPD 1 & 4] Use of the 2020 NEHRP Provisions for multi-period spectra shall be permitted, where all of the following are included.
- A detailed seismic design criterion shall be submitted to and approved by the AHJ.
- Seismic Ground Motion values shall be determined using the 2020 NEHRP Provisions, Section 11.4.
- Geologic Hazard and Geotechnical Investigation shall be performed using the 2020 NEHRP Provisions, Section 11.8.
- Vertical Ground Motions, where required, shall be determined using the 2020 NEHRP Provisions, Section 11.9.
- Site Classification shall be determined using the 2020 NEHRP Provisions, Chapter 20.
- Site-Specific Ground Motion Procedures shall be determined using the 2020 NEHRP Provisions, Chapter 21.
- Seismic Ground Motion and Long-period Transition Maps shall be used from Chapter 22 of the 2020 NEHRP Provisions.
- SDS and SD1 obtained from the multi-period spectra determined using the 2020 NEHRP Provisions shall be used, where required in Chapter 12, 13 and 15 of ASCE 7-16.
Modify ASCE 7, Table 12.2-1 as follows:
- A. BEARING WALL SYSTEMS
- 5. Intermediate Precast Shear Walls—Not permitted by OSHPD.
- 17. Light-framed walls with shear panels of all other materials—Not permitted by OSHPD and DSA-SS.
- B. BUILDING FRAME SYSTEMS
- 3. Ordinary steel concentrically braced frames—Not permitted by OSHPD.
- 8. Intermediate Precast Shear Walls—Not permitted by OSHPD.
- 24. Light-framed walls with shear panels of all other materials—Not permitted by OSHPD and DSA-SS.
- 26. Special steel plate shear wall—Not permitted by OSHPD.
- C. MOMENT-RESISTING FRAME SYSTEMS
- 2. Special steel truss moment frames—Not permitted by OSHPD.
- 3. Intermediate steel moment frames—Not permitted by OSHPD.
- 4. Ordinary steel moment frames—Not permitted by OSHPD.
- 12. Cold-formed steel—special bolted moment frame—Not permitted by DSA-SS and OSHPD.
- G. CANTILEVER COLUMN SYSTEMS DETAILED TO CONFORM WITH THE REQUIREMENTS FOR:
- 1. Steel special cantilever column systems—Not permitted by OSHPD.
- 3. Special reinforced concrete moment frames—Not permitted by OSHPD.
Exceptions:
- 1. Systems listed in this section can be used as an alternative system when preapproved by the enforcement agency.
- 2. Rooftop or other supported structures not exceeding two stories in height and 10 percent of the total structure weight can use the systems in this section when designed as components per ASCE 7, Chapter 13.
- 3. Systems listed in this section can be used for seismically isolated buildings, when permitted by ASCE 7, Section 17.2.5.4.
Modify ASCE 7, Sections 12.2.3, 12.2.3.1 and 12.2.3.2 as follows:
Replace ASCE 7, Section 12.2.3 with the following:
Where different seismic force-resisting systems are used in combinations to resist seismic forces in the same direction, other than those combinations considered as dual systems, the design shall comply with the requirements of this section. The most stringent applicable structural system limitations contained in Table 12.2-1 shall apply, except as otherwise permitted by this section.
Replace ASCE 7, Section 12.2.3.1, Items 1 and 2, by the following:
The value of the response modification coefficient, R, used for design at any story shall not exceed the lowest value of R that is used in the same direction at any story above that story. Likewise, the deflection amplification factor, Cd , and the system over strength factor, Ω0 , used for the design at any story shall not be less than the largest value of these factors that are used in the same direction at any story above that story.
Modify ASCE 7, Section 12.2.3.2 by modifying Item a and adding Items f, g and h, as follows:
- a. The stiffness of the lower portion shall be at least 10 times the stiffness of the upper portion. For purposes of determining this ratio, the base shear shall be computed and distributed vertically according to Section 12.8. Using these forces, the stiffness for each portion shall be computed as the ratio of the base shear for that portion to the elastic displacement, δxe , computed at the top of that portion, considering the portion fixed at its base. For the lower portion, the applied forces shall include the reactions from the upper portion, modified as required in Item d.
- f. The structural height of the upper portion shall not exceed the height limits of Table 12.2-1 for the seismic force-resisting system used, where the height is measured from the base of the upper portion. [OSHPD 1 & 4] Not permitted by OSHPD.
- g. Where Horizontal Irregularity Type 4 or Vertical Irregularity Type 4 exists at the transition from the upper to the lower portion, the reactions from the upper portion shall be amplified in accordance with Sections 12.3.3.3, 12.10.1.1 and 12.10.3.3 as applicable, in addition to amplification required by Item d.
- h. Where design of vertical elements of the upper portion is governed by special seismic load combinations, the special loads shall be considered in the design of the lower portion.
The exception after the first paragraph is not permitted by DSA-SS.
The exception after the first paragraph is not permitted by DSA-SS.
The exception after the first paragraph is not permitted by DSA-SS.
Modify first sentence of ASCE 7, Section 12.3.3.1 and add exceptions as follows:
12.3.3.1Prohibited horizontal and vertical irregularities for Seismic Design Categories D through F.
Structures assigned to Seismic Design Category D, E or F having horizontal structural irregularity Type 1b of Table 12.3-1 or vertical structural irregularities Type 1b, 5a or 5b of Table 12.3-2 shall not be permitted.
Exceptions:
-
Structures with reinforced concrete or reinforced masonry shear wall systems and rigid or semi-rigid diaphragms, consisting of concrete slabs or concrete-filled metal deck having a span-to-depth ratio of 3 or less, having a horizontal structural irregularity Type 1b of Table 12.3-1 are permitted, provided that the maximum story drift in the direction of the irregularity, computed including the torsional amplification factor from Section 12.8.4.3, is less than 10 percent of the allowable story drift in ASCE 7, Table 12.12-1.
-
Structures having a horizontal structural irregularity Type 1b of Table 12.3-1 are permitted, provided a redundancy factor, ρ, of 1.3 as defined in ASCE 7 12.3.4 is assigned to the seismic force-resisting system in both orthogonal directions and the structure is designed for one of the orthogonal procedures as defined in ASCE 7, Section 12.5.3.1.
Modify ASCE 7, Section 12.7.2, by adding Item 6 to read as follows:
- 6. Where buildings provide lateral support for walls retaining earth, and the exterior grades on opposite sides of the building differ by more than 6 feet (1829 mm), the load combination of the seismic increment of earth pressure due to earthquake acting on the higher side, as determined by a geotechnical engineer qualified in soils engineering plus the difference in earth pressures shall be added to the lateral forces provided in this section.
Replace ASCE 7 Equation 12.12-1 by the following:
(Equation 12.12-1)
Modify ASCE 7, Section 12.13.1 by adding Section 12.13.1.1 as follows:
The foundation shall be capable of transmitting the design base shear and the overturning forces from the structure into the supporting soil. Stability against overturning and sliding shall be in accordance with Section 1605A.1.1.
In addition, the foundation and the connection of the superstructure elements to the foundation shall have the strength to resist, in addition to gravity loads, the lesser of the following seismic loads:
- The strength of the superstructure elements.
- The maximum forces that can be delivered to the foundation in a fully yielded structural system.
- Forces from the load combinations with overstrength factor in accordance with ASCE 7, Section 12.4.3.1.
Exceptions:
- Where referenced standards specify the use of higher design loads.
- When it can be demonstrated that inelastic deformation of the foundation and superstructure-to-foundation connection will not result in a weak story or cause collapse of the structure.
- Where seismic force-resisting system consists of light framed walls with shear panels, unless the reference standard specifies the use of higher design loads.
Where the computation of the seismic overturning moment is by the equivalent lateral-force method or the modal analysis method, reduction in overturning moment permitted by section 12.13.4 of ASCE 7 may be used.
Modify ASCE 7, Section 12.13.9.2 by the following sentence added to the end of Item b as follows:
Seismic load effects determined in accordance with Section 12.4 need not be considered in this check.
Modify ASCE 7, Section 13.1.3 by the following:
All nonstructural components shall have a component importance factor, Ip, equal to 1.5.
Exception: Hospital buildings rated SPC-1 and SPC-2 not providing services/systems, utilities or access/egress to general acute care buildings designated as SPC 3 or higher in accordance with Chapter 6 of the California Administrative Code, shall be permitted to use component importance factor, Ip, as given in ASCE 7, Section 13.3.1.
Replace ASCE 7, Section 13.1.4, with the following:
13.1.4. The following nonstructural components and equipment shall be anchored in accordance with this section. Design and detailing shall be in accordance with Chapter 13 except as modified by this section.
- Fixed Equipment: Equipment shall be anchored if it is directly attached to the building utility services such as electricity, gas or water. For the purposes of this requirement, "directly attached" shall include all electrical connections except plugs for 110/220-volt receptacles having a flexible cable/cord. Equipment that is connected to the building plumbing system with a shut-off valve in proximity to the equipment shall not be considered as directly attached provided the inside diameter of the pipe/tubing is less than 1/2 inch (12.7 mm).
- Movable Equipment: Equipment is subject to the same requirement as fixed equipment, but is permitted to be anchored by re-attachable anchors or restraints in a manner approved by the enforcement agency. Utilities and services at the equipment shall have flexible connections to allow for necessary movement.
-
[OSHPD 1, 2, 4 & 5] Mobile Equipment: Equipment heavier than 400 pounds (181.4 kg) that has a center of mass located 4 feet (1219 mm) or more above the adjacent floor or roof level that directly support the equipment shall be restrained in a manner approved by the enforcement agency when stored and not in use, unless the equipment is stored in an equipment storage room.[DSA-SS] Mobile Equipment: Equipment heavier than 400 pounds (181.4 kg) or has a center of mass located 4 feet (1219 mm) or more above the adjacent floor or roof level that directly supports the equipment shall be restrained in a manner approved by the enforcement agency. Mobile equipment shall be restrained when not in use and is stored, unless the equipment is stored in a storage room that does not house hazardous materials or any facility systems or fixed equipment that can be affected by mobile equipment lacking restraint.
-
[OSHPD 1, 2, 4 & 5] Countertop Equipment: Countertop equipment shall be subject to the same anchorage or restraint requirements for fixed, movable, mobile or other equipment, as applicable.[DSA-SS] Countertop Equipment: Countertop equipment shall be subject to the same anchorage or restraint requirements for fixed or movable equipment, as applicable. Countertop equipment shall also be subject to the same requirements as mobile or other equipment if weight of equipment is greater than 100 pounds (45 kg) and has a center of mass located 4 feet (1219 mm) or more above the adjacent floor level or if equipment could fall and block a required means of egress.
-
[OSHPD 1, 2, 4 & 5] Temporary Equipment: Equipment for uses greater than 30 days but less than or equal to 180 days and where this section requires supports and attachments, the following shall apply:
- Seismic design for supports and attachments for temporary equipment shall meet the requirements of Chapter 13; however, the calculated Fp may be reduced by 50 percent. It is acceptable to use ballasts for seismic bracing supports and attachments and to limit the design criteria to overturning unless directly or indirectly supported by the building structure.
- Wind design speeds may be reduced as prescribed in ASCE 37-14 or other standard approved by OSHPD.
- Temporary piping, conductors and ductwork shall be supported. Seismic design for supports and attachments of temporary piping, conductors and ductwork is not required.
-
[OSHPD 1, 2, 4 & 5] Interim Equipment:
- Seismic design for supports and attachments for interim equipment shall meet the requirements of Chapter 13. It is acceptable to use ballasts for seismic or wind bracing supports and attachments.
- Wind design speeds may be reduced as prescribed in ASCE 37-14 or other standard approved by OSHPD.
- Piping, conductors and ductwork shall be supported. Seismic design for supports and attachments of piping, conductors and ductwork is not required.
-
Other Equipment: Equipment shall be anchored where any of the following apply:
-
[OSHPD 1, 2, 4 & 5] Essential to hospital operations and weight of equipment is greater than 100 pounds (45 kg).[DSA-SS] Weight of equipment is greater than 100 pounds (45 kg) and essential to operations for emergency preparedness, communications and operations centers, and other facilities required for emergency response of state-owned essential services buildings as defined in the California Administrative Code (Title 24, Part 1, CCR) Section 4-207 and all structures required for their continuous operation or access/egress.
- [OSHPD 1, 2, 4 & 5] Could fall within the patient care vicinity as defined in Article 517.2 of the California Electrical Code.
- Could fall and block a required means of egress. [OSHPD 1, 2, 4 & 5] Weight of equipment is greater than 400 pounds (181.4 kg).
-
[DSA-SS] Weight of equipment is greater than 400 pounds (181.4 kg) or center of mass is located greater than 4 feet (1219 mm) above the finished floor or roof level that directly supports the component.[OSHPD 1, 2, 4 & 5] Weight of equipment is greater than 200 pounds (90 kg) and center of mass located greater than 4 feet (1219 mm) measured from the finished floor.
-
- Equipment with hazardous contents.
- Other architectural, mechanical and electrical components stated in Chapter 13.
-
Wall-, Roof- or Floor-Hung Equipment: Seismic design and seismic details shall be provided for wall-, roof- or floor-hung nonstructural components and equipment when the component weighs more than 20 pounds (9 kg) [OSHPD 1, 2, 4 & 5] or, in the case of a distributed system, more than 5 pounds per foot (73 N/m).[OSHPD 1, 2, 4 & 5] Exemptions:
- Furniture except storage cabinets as noted in Table 13.5-1.
- Nonstructural components and equipment, that are attached to the building, provided that the component weighs 20 pounds (9 kg) or less or, in the case of a distributed system, 5 pounds per foot (73 N/m) or less. Seismic design and seismic details need not be provided.
- Seismic design need not be provided for discrete architectural, mechanical and electrical components and equipment that are attached to the building and anchorage is detailed on the plans, provided that the component weighs 400 pounds (18.44 kg) or less, and the center of mass is located 4 feet (1219 mm) or less above the adjacent floor or roof level that directly support the component and flexible connections are provided between the component and associated ductwork, piping and conduit where required.
[DSA-SS] Exemptions:The following nonstructural components are exempt from the requirements of ASCE 7, Chapter 13:- Furniture except storage cabinets as noted in Table 13.5-1.
- Discrete architectural, mechanical and electrical components and fixed equipment that are positively attached to the structure, provided that none of the conditions in this section apply, and flexible connections are provided between the component and associated ductwork, piping and conduit where required.
Replace ASCE 7, Sections 13.4.2.3, with the following:
13.4.2.3 Prequalified post-installed anchors and specialty inserts in concrete and masonry.
Post-installed anchors and specialty inserts in concrete that are pre-qualified for seismic applications in accordance with ACI 355.2, ACI 355.4, ICC-ES AC193, ICC-ES AC232, ICC-ES AC308 or ICC-ES AC446 shall be permitted. Post-installed anchors in masonry shall be pre-qualified for seismic applications in accordance with ICC-ES AC01, AC58 or AC106.
Use of screw anchors shall be limited to dry interior conditions and shall not be used in building enclosures. Re-use of screw anchors or screw anchor holes shall not be permitted.
Exception: [DSA-SS] Screw anchors are permitted for use in building enclosures and may also be used in exterior conditions when permitted in accordance with a valid evaluation report.
Modify ASCE 7, Section 13.4.5 by adding Section 13.4.5.1 as follows:
13.4.5.1 Power actuated fasteners. Power actuated fasteners qualified in accordance with ICC ES AC 70 shall be deemed to satisfy the requirements of Section 13.4.5.
Power actuated fasteners shall be permitted in seismic shear for components exempt from permit requirements by Section 1617A.1.18 of this code and for interior non-bearing non-shear wall partitions only. Power actuated fastener shall not be used to anchor seismic bracing, exterior cladding or curtain wall systems.
Exception: Power actuated fasteners in steel to steel connections prequalified for seismic application by cyclic tests in accordance with ICC ES AC 70 shall be permitted for seismic design.
Modify ASCE 7, Section 13.5.6.2 by the following exception added to the end of Section 13.5.6.2.2 and by adding Section 13.5.6.2.3 as follows:
Exception to Section 13.5.8.1 shall not be used in accordance with ASTM E580 Section 5.5.
13.5.6.2.3 Modification to ASTM E580. Modify ASTM E580 by the following:
- Exitways. Lay-in ceiling assemblies in exitways shall be installed with a main runner or cross runner surrounding all sides of each piece of tile, board or panel and each light fixture or grille. A cross runner that supports another cross runner shall be considered as a main runner for the purpose of structural classification. Splices or intersections of such runners shall be attached with through connectors such as pop rivets, screws, pins, plates with end tabs or other approved connectors. Lateral force diagonal bracing may be omitted in the short or transverse direction of exitways, not exceeding 8 feet wide, when perimeter support in accordance with ASTM E580 Sections 5.2.2 and 5.2.3 is provided and the perimeter wall laterally supporting the ceiling in the short or transverse direction is designed to carry the ceiling lateral forces. The connections between the ceiling grid, wall angle and the wall shall be designed to resist the ceiling lateral forces.
- Corridors and lobbies. Expansion joints shall be provided in the ceiling at intersections of corridors and at junctions of corridors and lobbies or other similar areas.
- Lay-in panels. Metal panels and panels weighing more than 1/2 pounds per square foot (24 N/m2) other than acoustical tiles shall be positively attached to the ceiling suspension runners.
- Lateral force bracing. Lateral force bracing is required for all ceiling areas except that they shall be permitted to be omitted in rooms with floor areas up to 144 square feet when perimeter support in accordance with ASTM E580, Sections 5.2.2 and 5.2.3, are provided and perimeter walls are designed to carry the ceiling lateral forces. The connections between the ceiling grid, wall angle and the wall shall be designed to resist the ceiling lateral forces. Horizontal restraint point spacing shall be justified by analysis or test and shall not exceed a spacing of 12 feet by 12 feet. Bracing wires shall be secured with four tight twists in 11/2 inches, or an approved alternate connection.
- Ceiling support and bracing wires shall be spaced a minimum of 6 inches from all pipes, ducts, conduits and equipment that are not braced for horizontal forces, unless approved otherwise by the building official.
[OSHPD 1 & 4] Modify ASCE 7, Section 13.5.7, by the following:
All access floors shall be special access floors in accordance with Section 13.5.7.2, except for raised roof or exterior floor paver systems.
Modify Section 13.6.2.1 by adding the following to the end of the section:
[OSHPD 1 & 4] Use of this section shall be considered as an alternative system. Alternatively, HVACR systems shall require special seismic certification in accordance with Section 1705A.13.3.
ASCE 7, Tables 13.5-1 and 13.6-1. Modify ASCE 7, Tables 13.5-1 & 13.6-1 by the following:
Where Ip = 1.5, overstrength factor (Ω0) need not exceed the values of Rp for design of anchorage to concrete.
Replace ASCE 7, Section 13.6.5 as follows:
13.6.5 Distribution Systems: Conduit, Cable Tray and Raceways. Cable trays and raceways shall be designed for seismic forces and seismic relative displacements as required in Section 13.3. Conduit equal to or greater than 2.5 inches (64 mm) trade size and attached to panels, cabinets or other equipment subject to seismic relative displacement, DpI, shall be provided with flexible connections or designed for seismic forces and seismic relative displacements as required in Section 13.3.
Exceptions:
- Design for the seismic forces and relative displacements of Section 13.3 shall not be required for raceways where flexible connections or other assemblies are provided between the cable tray or raceway and associated components to accommodate the relative displacement, where the cable tray or raceway is positively attached to the structure, and one of the following apply:
- Trapeze assemblies with 3/8 inch (10 mm) or 1/2 inch (13-mm) in diameter rod hangers not exceeding 12 inches (305 mm) in length from the conduit, cable tray or raceway support point to the connection at the supporting structure are used to support the cable tray or raceway, and the total weight supported by any single trapeze is 100 pounds (445 N) or less; or
- The conduit, cable tray or raceway is supported by individual rod hangers 3/8 inch (10 mm) or 1/2 inch (13 mm) in diameter, and each hanger in the raceway run is 12 inches (305 mm) or less in length from the conduit, cable tray or raceway support point connection to the supporting structure, and the total weight supported by any single rod is 50 pounds (220 N) or less.
- Design for the seismic forces and relative displacements of Section 13.3 shall not be required for conduit, regardless of the value of Ip, where the conduit is less than 2.5 inches (64 mm) trade size.
Design for the displacements across seismic joints shall be required for conduit, cable trays and raceways with Ip = 1.5 without consideration of conduit size.
Replace ASCE 7, Section 13.6.6 with the following:
13.6.6 Distribution Systems: Duct Systems. HVACR and other duct systems shall be designed for seismic forces and seismic relative displacements as required in Section 13.3.
Exceptions: The following exceptions pertain to ductwork not designed to carry toxic, highly toxic or flammable gases or not used for smoke control:
- Design for the seismic forces and relative displacements of Section 13.3 shall not be required for duct systems where flexible connections or other assemblies are provided to accommodate the relative displacement between the duct system and associated components, the duct system is positively attached to the structure, and where one of the following apply:
- Trapeze assemblies with 3/8-inch (10 mm) or 1/2-inch (13 mm) diameter rod hangers not exceeding 12 inches (305 mm) in length from the duct support point to the connection at the supporting structure are used to support duct, and the total weight supported by any single trapeze is less than 10 lb/ft (146 N/m) and 100 pounds or less; or
- The duct is supported by individual rod hangers 3/8 inch (10 mm) or 1/2 inch (13 mm) in diameter, and each hanger in the duct run is 12 inches (305 mm) or less in length from the duct support point to the connection at the supporting structure, and the total weight supported by any single rod is 50 pounds (220 N) or less.
- Design for the seismic forces and relative displacements of Section 13.3 shall not be required where provisions are made to avoid impact with other ducts or mechanical components or to protect the ducts in the event of such impact, the distribution system is positively attached to the structure; and HVACR ducts have a cross-sectional area of less than 6 square feet (0.557 m2) and weigh 20 lb/ft (292 N/m) or less.
Components that are installed in line with the duct system and have an operating weight greater than 75 pounds (334 N), such as fans, terminal units, heat exchangers and humidifiers, shall be supported and laterally braced independent of the duct system, and such braces shall meet the force requirements of Section 13.3.1. Components that are installed in line with the duct system, have an operating weight of 75 pounds (334 N) or less, such as small terminal units, dampers, louvers and diffusers, and are otherwise not independently braced shall be positively attached with mechanical fasteners to the rigid duct on both sides. Piping and conduit attached to in-line equipment shall be provided with adequate flexibility to accommodate the seismic relative displacements of Section 13.3.2.
Replace ASCE 7, Section 13.6.7.3 with the following:
13.6.7.3 Additional Provisions for Piping and Tubing Systems.
- Design for the seismic forces of Section 13.3 shall not be required for piping systems where flexible connections, expansion loops or other assemblies are provided to accommodate the relative displacement between component and piping, where the piping system is positively attached to the structure, and where any of the following conditions apply:
- Trapeze assemblies are supported by 3/8-inch (10 mm) or 1/2-inch (13 mm) diameter rod hangers not exceeding 12 inches (305 mm) in length from the pipe support point to the connection at the supporting structure, and no single pipe exceeds the diameter limits set forth in item 2b below or 2 inches (50 mm) where Ip is greater than 1.0 and the total weight supported by any single trapeze is 100 pounds (445 N) or less; or
- Piping that has an Rp in Table 13.6-1 of 4.5 or greater supported by rod hangers and provisions are made to avoid impact with other structural or nonstructural components or to protect the piping in the event of such impact, or pipes with Ip = 1.0 supported by individual rod hangers 3/8 inch (10 mm) or 1/2 inch (13 mm) in diameter, where each hanger in the pipe run is 12 inches (305 mm) or less in length from the pipe support point to the connection at the supporting structure; and the total weight supported by any single hanger is 50 pounds (220 N) or less. In addition, the following limitations on the size of piping shall be observed:
- In structures assigned to Seismic Design Category D, E or F where Ip is greater than 1.0, the nominal pipe size shall be 1 inch (25 mm) or less.
- In structures assigned to Seismic Design Categories D, E or F where Ip = 1.0, the nominal pipe size shall be 3 inches (80 mm) or less.
- Pneumatic tube systems supported with trapeze assemblies using 3/8 inch (10 mm) in diameter rod hangers not exceeding 12 inches (305 mm) in length from the tube support point to the connection at the supporting structure and the total weight supported by any single trapeze is 100 pounds (445 N) or less.
- Pneumatic tube systems supported by individual rod hangers 3/8 inch (10 mm) or 1/2 inch (13 mm) in diameter, and each hanger in the run is 12 inches (305 mm) or less in length from the tube support point to the connection at the supporting structure, and the total weight supported by any single rod is 50 pounds (220 N) or less.
- Flexible connections in piping required in Section 13.6.7.3 are not required where pipe is rigidly attached to the same floor or wall that provides vertical and lateral support for the equipment, or to a fixture.
- Flexible connections in piping are required at seismic separation joints and shall be detailed to accommodate the seismic relative displacements at connections.
Modify ASCE 7, Section 13.6.11.1, by adding Section 13.6.11.1.1 as follows:
13.6.11.1.1 Elevators guide rail support. The design of guide rail support-bracket fastenings and the supporting structural framing shall use the weight of the counterweight or maximum weight of the car plus not less than 40 percent of its rated load. The seismic forces shall be assumed to be distributed one third to the top guiding members and two thirds to the bottom guiding members of cars and counterweights, unless other substantiating data are provided. In addition to the requirements of ASCE 7, Section 13.6.11.1, the minimum seismic forces shall be 0.5g allowable stress design load acting in any horizontal direction.
Replace ASCE 7, Section 13.6.11.4, as follows:
13.6.11.4 Retainer plates. Retainer plates are required at the top and bottom of the car and counterweight, except where safety devices acceptable to the enforcement agency are provided which meet all requirements of the retainer plates, including full engagement of the machined portion of the rail. The design of the car, cab stabilizers, counterweight guide rails and counterweight frames for seismic forces shall be based on the following requirements:
- The seismic force shall be computed per the requirements of ASCE 7, Section 13.6.11.1. The minimum horizontal acceleration shall be 0.5g allowable stress design load for all buildings.
- Wp shall equal the weight of the counterweight or the maximum weight of the car plus not less than 40 percent of its rated load.
- With the car or counterweight located in the most adverse position, the stress in the rail shall not exceed the limitations specified in these regulations, nor shall the deflection of the rail relative to its supports exceed the deflection listed below:
RAIL SIZE (weight per foot oflength, pounds)WIDTH OF MACHINED SURFACE(inches)ALLOWABLE RAIL DEFLECTION(inches)8 1 1/4 0.20 11 1 1/2 0.30 12 1 3/4 0.40 15 1 31/32 0.50 18 1/2 1 31/32 0.50 22 1/2 2 0.50 30 2 1/4 0.50 For SI: 1 inch = 25 mm, 1 foot = 305 mm, 1 pound = 0.454 kg.Note: Deflection limitations are given to maintain a consistent factor of safety against disengagement of retainer plates from the guide rails during an earthquake. - Where guide rails are continuous over supports and rail joints are within 2 feet (610 mm) of their supporting brackets, a simple span may be assumed.
- The use of spreader brackets is allowed.
- Cab stabilizers and counterweight frames shall be designed to withstand computed lateral load with a minimum horizontal acceleration of 0.5g allowable stress design load.
Modify ASCE 7, Section 17.2.4.7, by adding the following:
The effects of uplift shall be explicitly accounted for in the testing of the isolator units.
Modify ASCE 7, Section 17.4.2, by adding the following:
17.4.2.3 Linear procedures. Linear procedures shall not be used in Seismic Design Category E & F structures.
Replace exception to ASCE 7, Section 18.3 with the following:
Exception: If the calculated force in an element of the seismic force-resisting system does not exceed 1.5 times its nominal strength for the Risk-Targeted Maximum Considered Earthquake (MCER) the element is permitted to be modeled as linear. For this section, the MCER response shall be based on largest response due to a single ground motion and not the average response of suite of ground motions.
[OSHPD 1 & 4] Modify ASCE 7 by the following:
Scope: For buildings with a seismic isolation system, a damping system or a lateral force-resisting system (LFRS) not listed in ASCE 7 Table 12.2-1, earthquake motion measuring instrumentation and monitoring shall be required. For buildings with welded steel moment frames constructed under a permit issued prior to October 25, 1994 post-earthquake verification shall be in accordance with this section.
Instrumentation: Earthquake monitoring instrumentation shall be installed in accordance with Section 104.11.4.
Monitoring: After every significant seismic event, where the ground shaking acceleration at the site exceeds 0.3g or the acceleration at any monitored building level exceeds 0.8g as measured by the seismic monitoring system in the building, the owner shall retain a structural engineer to make an inspection of the structural system. The inspection shall include viewing the performance of the building, reviewing the strong motion records, and a visual examination of the isolators, dampers and connections for deterioration, offset or physical damage. A report for each inspection, including conclusions on the continuing adequacy of the structural system, shall be submitted to the enforcement agency.
Verification: After every seismic event that generates ground motions specified in the California Administrative Code, Chapter 6, Section 4.2.0.1 or the damage indicators specified in the California Administrative Code, Chapter 6, Section 4.2.0.2 at a welded steel moment frame building constructed under a permit issued prior to October 25, 1994, the owner shall retain a structural engineer to perform detailed joint evaluations required to meet the following requirements:
- A detailed joint evaluation program shall be submitted to the enforcement agency for approval prepared in accordance with the requirements of the California Administrative Code, Chapter 6, Section 4.2.0.3.
- Upon approval of the joint evaluation program required by Item 1 above for the joint inspections, a project to perform the joint inspections, detailed in the program, shall be submitted and a building permit shall be obtained by the owner no later than 6 months from the date of occurrence of the seismic event.
- A detailed joint evaluation report shall be submitted to the enforcement agency no later than 6 months of obtaining the building permit. The report shall document the findings from the inspections of the joints and include conclusions on the adequacy of the structural system. Where unsafe conditions are discovered, the provisions of Section 116 shall apply.
[OSHPD 1 & 4] New general acute care hospitals and new building(s) required for general acute care services shall satisfy Operational Nonstructural Performance Level (NPC-5) requirements.
Exception: A new building which is required for general acute care services that is added to an existing general acute care hospital and which has a building area of 4,000 square feet (371 m2) or less, need not satisfy the NPC-5 requirements until the deadline specified in California Administrative Code (Part 1, Title 24 CCR), Chapter 6.
Hospitals and buildings designed and constructed to the provisions of this code for new construction shall be deemed to satisfy Operational Nonstructural Performance Level (NPC-5) requirements when:
- The facility has on-site supplies of water and holding tanks for sewage and liquid waste, sufficient to support 72 hours of emergency operations for the hospital or building, which are integrated into the building plumbing systems in accordance with the California Plumbing Code.
- An on-site emergency system as defined in the California Electrical Code is incorporated into the building electrical system for critical care areas. Additionally, the system shall provide for radiological service and an onsite fuel supply for 72 hours of acute care operation.
Emergency and standby generators shall not be located below the higher of the Design Flood Elevation (DFE) or Base Flood Elevation (BFE) plus two feet (BFE + 2 ft.) or 500 year flood elevation, whichever is higher, and shall be located at an elevation close to grade for easy accessibility from outside for maintenance.
[OSHPD 1, 1R, 2, 4, & 5]
- General. Independent peer review is an objective technical review by knowledgeable reviewer(s) experienced in structural design, analysis and performance issues involved. The reviewer(s) shall examine the available information on the condition of the building, basic engineering concept employed and recommendations for action.
- Timing of Independent Review. The independent reviewer (s) shall be selected prior to initiation of substantial portion of the design and analysis work that is to be reviewed, and review shall start as soon as practical and sufficient information defining the project is available.
- Qualifications and Terms of Employment. The reviewer shall be independent from the design and construction team.
- The reviewer(s) shall have no other involvement in the project before, during or after the review, except in a review capacity.
- The reviewer shall be selected and paid by owner and shall have technical expertise similar to the project being reviewed, as determined by enforcement agent.
- The reviewer (in case of review team, the chair) shall be a California-licensed structural engineer who is familiar with technical issues and regulations governing the work to be reviewed.
- The reviewer shall serve through completion of the project and shall not be terminated except for failure to perform the duties specified herein. Such termination shall be in writing with copies to enforcement agent, owner and the engineer of record. When a reviewer is terminated or resigns, a qualified replacement shall be appointed within 10 working days or a timeframe mutually agreed to by the Owner, Registered Design Professional (RDP) and the Office.
- Scope of Review. Review activities shall include, where appropriate, available construction documents, design criteria, observation of the condition of structure, all new and original inspection reports, including methods of sampling, analyses prepared by the engineer of record and consultants, and the new, retrofit or repair design. Review shall include consideration of the proposed design approach, method, materials and details.
- Reports. The reviewer(s) shall prepare a written report to the owner and responsible enforcement agent that covers all aspect of the review performed including conclusions reached by the reviewer. Report shall be issued after the schematic phase, during design development, and at the completion of construction documents, but prior to their issuance of permit. Such report shall include, at the minimum, statement of the following:
- Scope of engineering design peer review with limitations defined.
- The status of the project documents at each review stage.
- Ability of selected materials and framing systems to meet the performance criteria with given loads and configuration.
- Degree of structural system redundancy and the deformation compatibility among structural and nonstructural elements.
- Basic constructability of the new, retrofit or repair system.
- Other recommendation that will be appropriate for the specific project.
- Presentation of the conclusions of the reviewer identifying any areas that need further review, investigation and/or clarification.
- Recommendations.