Modify ASCE 7 Section 1.3 by the adding Section 1.3.6 as follows:
1.3.6 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.
Replace last paragraph of ASCE 7, Section 11.1.3, by the following:
Buildings shall be designed and detailed in accordance with Chapter 12.
Modify ASCE 7 Table 12.2-1 as follows:
- Special steel truss moment frames—Not permitted by OSHPD.
- Intermediate steel moment frames—Not permitted by OSHPD.
- Ordinary steel moment frames—Not permitted by OSHPD.
- Cold-formed steel–special bolted moment frame - Not permitted by DSA-SS and OSHPD.
- Systems listed in this section can be used as an alternative system when preapproved by the enforcement agency.
- 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.
- Systems listed in this section can be used for seismically isolated buildings when permitted by Section 1613A.4.1.
Replace ASCE 7, Section 126.96.36.199, 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 188.8.131.52, by adding the following additional requirements:
f. Where design of 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.
[DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.
[DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.
[DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.
Modify first sentence of ASCE 7, Section 184.108.40.206, as follows:
220.127.116.11 Prohibited 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.
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, Section 18.104.22.168, by the following:
22.214.171.124 Maximum SDS value in determination of Cs and Ev. The value of Cs and Ev are permitted to be calculated using a value of SDS equal to 1.0, but not less than 70% of SDS as defined in Section 11.4.4, provided that all of the following criteria are met:
- The structure does not have irregularities, as defined in Section 12.3.2;
- The structure does not exceed five stories above the base as defined in Section 11.2;
- The structure has a fundamental period, T, that does not exceed 0.5 seconds, as determined using Section 12.8.2;
- The structure meets the requirements necessary for the redundancy factor, ρ, to be permitted to be taken as 1.0, in accordance with Section 126.96.36.199;
- The site soil properties are not classified as Site Class E or F, as defined in Section 11.4.2; and
- The structure is classified as Risk Category I or II, as defined in Section 1.5.1.
- [OSHPD 1 & 4] The structure is a nonconforming building not supporting SPC-3 or higher buildings.
Replace ASCE 7, Exception 1 of Section 188.8.131.52, by adding the following:
- The forces calculated above need not exceed those calculated using the load combinations of Section 184.108.40.206 with seismic forces determined by Equation 12.10-3 and transfer forces, where applicable.
[OSHPD 1 & 4] Replace ASCE 7 Equation 12.12-1 by the following:
Modify ASCE 7 Section 12.13.1 by adding Section 220.127.116.11 as follows:
18.104.22.168 Foundations and superstructure-to-foundation connections. 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 over-strength factor in accordance with ASCE 7, Section 22.214.171.124.
- 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.
Where moment resistance is assumed at the base of the superstructure elements, the rotation and flexural deformation of the foundation as well as deformation of the superstructure-to-foundation connection shall be considered in the drift and deformation compatibility analyses.
[OSHPD 1 & 4] 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: Freestanding skilled nursing or acute psychiatric buildings, 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 shown in Table 1616A.1.17.
COMPONENT IMPORTANCE FACTOR (Ip)1 FOR FREESTANDING SKILLED NURSING AND ACUTE PSYCHIATRIC BUILDINGS
|DESCRIPTION||IMPORTANCE FACTOR (Ip)1|
|Mechanical and electrical components||1.5|
|Piping, including in-line components||1.5|
|HVAC ducts, including in-line components||1.0|
- Components required for life-safety purposes after an earthquake, including emergency and standby power systems, mechanical smoke removal systems, fire protection sprinkler systems, fire alarm control panels, and egress stairways shall have a component importance factor (Ip) of 1.5.
Replace ASCE 7, Section 13.1.4, with the following:
13.1.4 Exemptions. The following nonstructural components are exempt from the requirements of this section:
- Furniture (except storage cabinets as noted in Table 13.5-1).
- Equipment shall be anchored if it is permanently attached to the building utility services such as electricity, gas or water. For the purposes of this requirement, “permanently attached” shall include all electrical connections except plugs for duplex receptacles.
- The enforcement agency shall be permitted to require temporary attachments for movable equipment which is usually stationed in one place and heavier than 400 pounds or has a center of mass located 4 feet (1.22 m) or more above the adjacent floor or roof level that directly support the component, when they are not in use for a period longer than 8 hours at a time.
- The component is positively attached to the structure;
- The component weighs 20 pounds (89 N) or less or, in the case of a distributed system, 5 lb/ft (73 N/m) or less.
Exception: The enforcement agency shall be permitted to require attachments for equipment with hazardous contents to be shown on construction documents irrespective of weight.
Replace ASCE 7, Sections 126.96.36.199, with the following:
188.8.131.52 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 not prohibited for use in building enclosures.
Modify ASCE 7 Section 13.4.5 by adding Section 184.108.40.206 as follows:
220.127.116.11 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 1616A.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.
Replace ASCE 7, Section 13.5.6 with the following:
13.5.6 Suspended ceilings. Suspended ceilings shall be in accordance with this section.
18.104.22.168 Seismic forces. The weight of the ceiling, Wp, shall include the ceiling grid; ceiling tiles or panels; light fixtures if attached to, clipped to, or laterally supported by the ceiling grid; and other components that are laterally supported by the ceiling. Wp shall be taken as not less than 4 psf (19 N/m2).
The seismic force, Fp, shall be transmitted through the ceiling attachments to the building structural elements or the ceiling-structure boundary.
22.214.171.124 Seismic design requirements. Suspended acoustical tile or lay-in panel ceilings shall be designed in accordance with ASTM E580, Section 5.2.8, and the requirements of Sections 126.96.36.199.1 and 188.8.131.52.2, or be designed in accordance with Section 13.2.1.(1), or be seismically qualified in accordance with Sections 13.2.5 or 13.2.6.
184.108.40.206.1 Industry standard construction for acoustical tile or lay-in panel ceilings. Acoustical tile or lay-in panel ceilings in Seismic Design Categories D, E, and F shall be designed and installed in accordance with ASTM C635, ASTM C636, and ASTM E580, Section 5 - Seismic Design Categories D, E, and F as modified by Section 220.127.116.11.2.
Exception to Section 18.104.22.168 shall not be used in accordance with ASTM E580 Section 5.5.
22.214.171.124.2 Modification to ASTM E580. Modify ASTM E580 by the following:
- Exitways. Lay-in ceiling assemblies in exit-ways of hospitals and essential services buildings 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” 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 126.96.36.199.
Modify ASCE 7, Tables 13.5-1 & 13.6-1 by the following:
- For components with Rp greater than 1.5, over-strength factor (Ω0) for design of anchorage to concrete and vibration isolators along with associated snubbers/connections shall be 2.0.
- For Exterior Nonstructural Wall Elements and Connections, overstrength factor (Ω0) shall be 1.0.
Modify ASCE 7, Section 188.8.131.52, Exceptions 1 and 2, as follows:
- Trapeze assemblies are used to support raceways and the total weight of the race-way supported by trapeze assemblies is less than 10 lb/ft (146 N/m), or
- The raceway is supported by hangers and each hanger in the raceway run is 12 in. (305 mm) or less in length from the race-way support point to the supporting structure. Where rod hangers are used with a diameter greater than 3/8 inch, they shall be equipped with swivels to prevent inelastic bending in the rod.
- Design for the seismic forces of Section 13.3 shall not be required for conduit, regardless of the value of Ip , where the conduit is up to 2.5 in. (64 mm) trade size.
Replace ASCE 7, Section 13.6.7, Exceptions 1 and 2, with the following:
The following exceptions pertain to ductwork not designed to carry toxic, highly toxic, or flammable gases or used for smoke control:
- Trapeze assemblies are used to support ductwork and the total weight of the ductwork supported by trapeze assemblies is less than 10 lb/ft (146 N/m); or
- The ductwork is supported by hangers and each hanger in the duct run is 12 in. (305 mm) or less in length from the duct support point to the supporting structure. Where rod hangers are used with a diameter greater than 3/8 inch, they shall be equipped with swivels to prevent inelastic bending in the rod.
- Design for the seismic forces of Section 13.3 shall not be required where provisions are made to avoid impact with larger ducts or mechanical components or to protect the ducts in the event of such impact; and HVAC ducts have a cross-sectional area of 6 ft2 (0.557 m2) or less, or weigh 10 lb/ft (146 N/m) or less.
Replace ASCE 7, Section 184.108.40.206 with the following:
220.127.116.11 Exceptions. Design of piping systems and attachments for the seismic forces of Section 13.3 shall not be required where one of the following conditions apply:
- Trapeze assemblies are used to support piping whereby no single pipe exceeds the limits set forth in 3a. or b. below and the total weight of the piping supported by the trapeze assemblies is less than 10 lb/ft (146 N/m).
- The piping is supported by hangers and each hanger in the piping run is 12 in. (305 mm) or less in length from the top of the pipe to the supporting structure. Where pipes are supported on a trapeze, the trapeze shall be supported by hangers having a length of 12 in. (305 mm) or less. Where rod hangers are used with a diameter greater than 3/8 inch, they shall be equipped with swivels, eye nuts or other devices to prevent bending in the rod.
The exceptions above shall not apply to elevator piping.
Modify ASCE 7, Section 18.104.22.168, by adding Section 22.214.171.124.1 as follows:
126.96.36.199.1 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 188.8.131.52, the minimum seismic forces shall be 0.5g acting in any horizontal direction.
Replace ASCE 7, Section 184.108.40.206, as follows:
220.127.116.11 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 counter-weight frames for seismic forces shall be based on the following requirements:
- The seismic force shall be computed per the requirements of ASCE 7 Section 18.104.22.168. The minimum horizontal acceleration shall be 0.5g 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.
RAIL SIZE (weight per foot of length, pounds) WIDTH OF MACHINED SURFACE (inches) ALLOWABLE RAIL DEFLECTION (inches) 8 11/4 0.20 11 11/2 0.30 12 13/4 0.40 15 131/32 0.50 181/2 131/32 0.50 221/2 2 0.50 30 21/4 0.50
- 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.
Modify ASCE 7, Section 16.2.2, by adding the following:
Requirements of this section shall be deemed to be satisfied for new buildings, using acceptance criteria, in Section 22.214.171.124, by the nonlinear modeling parameters in ASCE 41.
Modify ASCE 7, Section 16.2.3, by adding the following:
Requirements of this section shall be deemed to be satisfied by using load combinations in Sections 126.96.36.199 and 188.8.131.52 with 25 percent of the required live loads.
Modify ASCE 7, Section 16.2.4, by the following:
- Each of the ground motions shall have their maximum component at the fundamental period aligned in one direction.
- Each of the ground motion’s maximum component shall be rotated orthogonal to the previous analysis direction.
- Where site is located more than 3.1 miles (5 km) from an active fault at least 10 ground motions shall be analyzed. The ground motions shall be applied such that one-half shall have their maximum component aligned in one direction and the other half aligned in the orthogonal direction. The average of the maximum response of all the analyses shall be used for design.
Replace ASCE 7 exception to Section 16.2.3 by the following:
Where this standard requires the consideration of the load combinations with overstrength factor of Section 184.108.40.206, average demand from MCE analysis obtained from suite of analysis in accordance with Section 16.2.4 shall be used with Immediate Occupancy (IO) acceptance criteria in Section 220.127.116.11.
Modify ASCE 7, Section 18.104.22.168, by the following:
Acceptance criteria for elements subjected to deformation beyond their linear range of response shall be based on ASCE 41 for Immediate Occupancy (IO) at Design Earthquake (DE) and Life Safety (LS) at Maximum Considered Earthquake (MCER).
Modify ASCE 7, Section 22.214.171.124, 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:
126.96.36.199 Linear procedures. Linear procedures shall not be used in Seismic Design Category E & F structures.
Modify ASCE 7, Section 17.6, by the following:
188.8.131.52 Minimum seismic force. For the response spectrum and linear response history procedures, Vb and Vs shall not be taken less than those calculated in accordance with Equations 17.5-7 and 17.5-8.
Modify ASCE 7, Section 18.3.1, by replacing the third paragraph with the following:
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) nor its nominal strength for the design earthquake (DE), the element is permitted to be modeled as linear. For this section, the MCER and DE 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 welded steel moment frames constructed under a permit issued prior to October 25, 1994 post-earthquake verification shall be in accordance with this section.
Verification: After every seismic event that generates ground motions specified in the California Administrative Code, Chapter 6, Section 184.108.40.206 or the damage indicators specified in the California Administrative Code, Chapter 6, Section 220.127.116.11 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 18.104.22.168.
- 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.
Where the detailed joint evaluation report is not submitted within the timeframes specified above, the building shall not be issued a building permit for any projects except for those for seismic compliance, maintenance and repair until the detailed joint evaluation work is complete.
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.