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 12.4.2 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 | = | Roof live load greater than 20 psf (0.96 kN/m2) and floor live load. |
Lr | = | Roof live load of 20 psf (0.96 kN/m2) or less. |
R | = | Rain load. |
S | = | Snow load. |
T | = | Self-straining load. |
Vasd | = | Nominal design wind speed (3-second gust), miles per hour (mph) (km/hr) where applicable. |
Vult | = | Ultimate design wind speeds (3-second gust), miles per hour (mph) (km/hr) determined from Figures 1609A, 1609B, or 1609C or ASCE 7. |
W | = | Load due to wind pressure. |
Wi | = | Wind-on-ice in accordance with Chapter 10 of ASCE 7. |
- Floor and roof live loads.
- Ground snow load, Pg.
- Ultimate design wind speed, Vult, (3-second gust), miles per hour (mph) (km/hr) and nominal design wind speed, Vasd, as determined in accordance with Section 1609.3.1 and wind exposure.
- Seismic design category and site class.
- Flood design data, if located in flood hazard areas established in Section 1612.3.
- Design load-bearing values of soils.
- Flat-roof snow load, Pf.
- Snow exposure factor, Ce.
- Snow load importance factor, Is.
- Thermal factor, Ct.
- Ultimate design wind speed, Vult, (3-second gust), miles per hour (km/hr) and nominal design wind speed, Vasd, as determined in accordance with Section 1609.3.1.
- Risk category.
- Wind exposure. Applicable wind direction if more than one wind exposure is utilized.
- Applicable internal pressure coefficient.
- Design wind pressures to be used for exterior component and cladding materials not specifically designed by the registered design professional responsible for the design of the structure, psf (kN/m2).
- 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.
- In flood hazard areas not subject to high-velocity wave action, the elevation of the proposed lowest floor, including the basement.
- In flood hazard areas not subject to high-velocity wave action, the elevation to which any nonresidential building will be dry flood proofed.
- In flood hazard areas subject to high-velocity wave action, the proposed elevation of the bottom of the lowest horizontal structural member of the lowest floor, including the basement.
Loads and forces for occupancies or uses not covered in this chapter shall be subject to the approval of the building official.
CONSTRUCTION | L | S or W f | D + Ld, 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 and interior partitions: | |||
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 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.
- Interior partitions not exceeding 6 feet in height and 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 1607.14.
- See Section 2403 for glass supports.
- For wood structural members having a moisture content of less than 16 percent at time of installation and used under dry conditions, the deflection resulting from L + 0.5D is permitted to be substituted for the deflection resulting from L + D.
- The above deflections do not ensure against ponding. Roofs that do not have sufficient slope or camber to assure adequate drainage shall be investigated for ponding. See Section 1611 for rain and ponding requirements and Section 1503.4 for roof drainage requirements.
- The wind load is permitted to be taken as 0.42 times the "component and cladding" loads for the purpose of determining deflection limits herein.
- For steel structural members, the dead load shall 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 l/120.
- For cantilever members, l shall be taken as twice the length of the cantilever.
Members that tend to accumulate residual deformations under repeated service loads shall have included in their analysis the added eccentricities 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 their effect on the action of the system is considered and provided for in the design. Except where diaphragms are flexible, or are permitted to be analyzed as flexible, 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 overturning effects caused by the lateral forces specified in this chapter. See Section 1609 for wind loads, Section 1610 for lateral soil loads and Section 1613 for earthquake loads.
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 1004.1.2 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 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.
- The reactions resulting from the dead load and live load specified in Table 1607.1, or the snow load specified in Section 1608, in accordance with Section 1605, acting on all portions of the deck.
- The reactions resulting from the dead load and live load specified in Table 1607.1, or the snow load specified in Section 1608, in accordance with Section 1605, acting on the cantilevered portion of the deck, and no live load or snow load on the remaining portion of the deck.
- The load combinations specified in Section 1605.2, 1605.3.1 or 1605.3.2;
- The load combinations specified in Chapters 18 through 23; and
- The seismic load effects including overstrength factor in accordance with Section 12.4.3 of ASCE 7 where required by Section 12.2.5.2, 12.3.3.3 or 12.10.2.1 of ASCE 7. With the simplified procedure of ASCE 7 Section 12.14, the seismic load effects including overstrength factor in accordance with Section 12.14.3.2 of ASCE 7 shall be used.
Applicable loads shall be considered, including both earthquake and wind, in accordance with the specified load combinations. Each load combination shall also be investigated with one or more of the variable loads set to zero.
Where the load combinations with overstrength factor in Section 12.4.3.2 of ASCE 7 apply, they shall be used as follows:
- The basic combinations for strength design with overstrength factor in lieu of Equations 16-5 and 16-7 in Section 1605.2.
- The basic combinations for allowable stress design with overstrength factor in lieu of Equations 16-12, 16-14 and 16-16 in Section 1605.3.1.
- The basic combinations for allowable stress design with overstrength factor in lieu of Equations 16-21 and 16-22 in Section 1605.3.2.
1.4(D +F) | (Equation 16-1) |
1.2(D + F) + 1.6(L + H) + 0.5(Lr or S or R) | (Equation 16-2) |
1.2(D + F) + 1.6(Lr or S or R) + 1.6H + (f1L or 0.5W) | (Equation 16-3) |
1.2(D + F) + 1.0W + f1L + 1.6H + 0.5(Lr or S or R) | (Equation 16-4) |
1.2(D + F) + 1.0E + f1L + 1.6H + f2S | (Equation 16-5) |
0.9D+ 1.0W+ 1.6H | (Equation 16-6) |
0.9(D + F) + 1.0E+ 1.6H | (Equation 16-7) |
where:
f1 | = | 1 for places of public assembly live loads in excess of 100 pounds per square foot (4.79 kN/m2), and parking garages; and 0.5 for other live loads. |
f2 | = | 0.7 for roof configurations (such as saw tooth) that do not shed snow off the structure, and 0.2 for other roof configurations. |
- Where other factored load combinations are specifically required by other provisions of this code, such combinations shall take precedence.
- Where the effect of H resists the primary variable load effect, a load factor of 0.9 shall be included with H where H is permanent and H shall be set to zero for all other conditions.
D + F | (Equation 16-8) |
D + H + F + L | (Equation 16-9) |
D + H + F + (Lr or S or R) | (Equation 16-10) |
D + H + F+ 0.75(L) + 0.75(Lr or S or R) | (Equation 16-11) |
D + H + F + (0.6W or 0.7E) | (Equation 16-12) |
D + H + F + 0.75(0.6W) + 0.75L + 0.75(Lr or S or R) | (Equation 16-13) |
D + H + F + 0.75 (0.7 E) + 0.75 L + 0.75 S | (Equation 16-14) |
0.6D + 0.6W+H | (Equation 16-15) |
0.6(D + F) + 0.7E+H | (Equation 16-16) |
- Crane hook loads need not be combined with roof live load or with more than three-fourths of the snow load or one-half of the wind load.
- Flat roof snow loads of 30 psf (1.44 kN/m2) or less and roof live loads of 30 psf (1.44 kN/m2) or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 psf (1.44 kN/m2), 20 percent shall be combined with seismic loads.
- Where the effect of H resists the primary variable load effect, a load factor of 0.6 shall be included with H where H is permanent and H shall be set to zero for all other conditions.
- In Equation 16-15, the wind load, W, is permitted to be reduced in accordance with Exception 2 of Section 2.4.1 of ASCE 7.
- In Equation 16-16, 0.6 D is permitted to be increased to 0.9 D for the design of special reinforced masonry shear walls complying with Chapter 21.
D + L + (Lr or S or R) | (Equation 16-17) |
D + L + 0.6 ωW | (Equation 16-18) |
D + L + 0.6 ωW + S/2 | (Equation 16-19) |
D + L + S + 0.6 ωW/2 | (Equation 16-20) |
D + L + S + E/1.4 | (Equation 16-21) |
0.9D + E/1.4 | (Equation 16-22) |
- 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 psf (1.44 kN/m2) or less and roof live loads of 30 psf (1.44 kN/m2) or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 psf (1.44 kN/m2), 20 percent shall be combined with seismic loads.
OCCUPANCY OR USE | UNIFORM (psf) | CONCENTRATED (lbs.) |
---|---|---|
1. Apartments (see residential) | — | — |
2. Access floor systems | ||
Office use
|
50 | 2,000 |
Computer use
|
100 | 2,000 |
3. Armories and drill rooms | 150m | — |
4. Assembly areas | — | |
Fixed seats (fastened to floor)
|
60m | |
Follow spot, projections and control rooms
|
50 | |
Lobbies
|
100m | |
Movable seats
|
100m | |
Stage floors
|
150m | |
Platforms (assembly)
|
100m | |
Other assembly areas
|
100m | |
5. Balconies and decksh | Same as occupancy served | — |
6. Catwalks | 40 | 300 |
7. Cornices | 60 | — |
8. Corridors | — | |
First floor
|
100 | |
Other floors
|
Same as occupancy served except as indicated |
|
9. Dining rooms and restaurants | 100m | — |
10. Dwellings (see residential) | — | — |
11. Elevator machine 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. Garages (passenger vehicles only) | 40m | Note a |
Trucks and buses
|
See Section 1607.7 | |
15. Handrails, guards and grab bars | See Section 1607.8 | |
16. Helipads | See Section 1607.6 | |
17. Hospitals | ||
Corridors above first floor
|
80 | 1,000 |
Operating rooms, laboratories
|
60 | 1,000 |
Patient rooms
|
40 | 1,000 |
18. Hotels (see residential) | — | — |
19. Libraries | ||
Corridors above first floor
|
80 | 1,000 |
Reading rooms
|
60 | 1,000 |
Stack rooms
|
150b, m | 1,000 |
20. Manufacturing | ||
Heavy
|
250m | 3,000 |
Light
|
125m | 2,000 |
21. Marquees | 75 | — |
22. Office buildings | ||
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 |
23. Penal institutions | — | |
Cell blocks
|
40 | |
100 | ||
24. Recreational uses: | — | |
Bowling alleys, poolrooms and similar uses
|
75m | |
Dance halls and ballrooms
|
100m | |
Gymnasiums
|
100m | |
Reviewing stands, grandstands and bleachers
|
100c, m | |
Stadiums and arenas with fixed seats (fastened to floor)
|
60c, m | |
25. Residential | — | |
One- and two-family dwellings
|
||
Uninhabitable attics without storagei
|
10 | |
Uninhabitable attics with storagei, j, k
|
20 | |
Habitable attics and sleeping areask
|
30 | |
All other areas
|
40 | |
Hotels and multi-family dwellings
|
||
Private rooms and corridors serving them
|
40 | |
Public roomsm and corridors serving them
|
100 | |
26. Roofs | ||
All roof surfaces subject to maintenance workers
|
300 | |
Fabric construction supported by a skeleton structure
|
5 nonreducible |
|
All other construction
|
20 | |
Ordinary flat, pitched, and curved roofs (that are not occupiable)
|
20 | |
Primary roof members exposed to a work floor
|
||
2,000 | ||
All other primary roof members
|
300 | |
Occupiable roofs:
|
||
Roof gardens
|
100 | |
Assembly areas
|
100m | |
All other similar areas
|
Note 1 | Note 1 |
27. Schools | ||
Classrooms
|
40 | 1,000 |
Corridors above first floor
|
80 | 1,000 |
First-floor corridors
|
100 | 1,000 |
28. Scuttles, skylight ribs and accessible ceilings | — | 200 |
29. Sidewalks, vehicular driveways and yards, subject to trucking | 250d, m | 8,000e |
30. Stairs and exits | ||
One- and two-family dwellings
|
40 | 300f |
All other
|
100 | 300f |
31. Storage warehouses (shall be designed for heavier loads if required for anticipated storage) | — | |
Heavy
|
250m | |
Light
|
125m | |
32. Stores | ||
Retail
|
||
First floor
|
100 | 1,000 |
Upper floors
|
75 | 1,000 |
Wholesale, all floors
|
125m | 1,000 |
33. Vehicle barriers | See Section 1607.8.3 | |
34. Walkways and elevated platforms (other than exitways) | 60 | — |
35. Yards and terraces, pedestrians | 100m | — |
- Floors in garages or portions of buildings used for the storage of motor vehicles shall be designed for the uniformly distributed live loads of Table 1607.1 or the following concentrated loads: (1) for garages restricted to passenger vehicles accommodating not more than nine passengers, 3,000 pounds acting on an area of 4.5 inches by 4.5 inches; (2) for mechanical parking structures without slab or deck that are used for storing passenger vehicles only, 2,250 pounds per wheel.
- The loading applies to stack room floors that support nonmobile, double-faced library book stacks, subject to the following limitations:
- Design in accordance with ICC 300.
- Other uniform loads in accordance with an approved method containing provisions for truck loadings shall also be considered where appropriate.
- The concentrated wheel load shall be applied on an area of 4.5 inches by 4.5 inches.
- The minimum concentrated load on stair treads shall be applied on an area of 2 inches by 2 inches. This load need not be assumed to act concurrently with the uniform load.
- Where snow loads occur that are in excess of the design conditions, the structure shall be designed to support the loads due to the increased loads caused by drift buildup or a greater snow design determined by the building official (see Section 1608).
- See Section 1604.8.3 for decks attached to exterior walls.
- Uninhabitable attics without storage are those where the maximum clear height between the joists and rafters is less than 42 inches, or where there are not two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches in height by 24 inches in width, or greater, within the plane of the trusses. This live load need not be assumed to act concurrently with any other live load requirements.
- Uninhabitable attics with storage are those where the maximum clear height between the joists and rafters is 42 inches or greater, or where there are two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches in height by 24 inches in width, or greater, within the plane of the trusses.
The live load 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 accessible from an opening not less than 20 inches in width by 30 inches in length that is located where the clear height in the attic is a minimum of 30 inches; and
- The slopes of the joists or truss bottom chords are no greater than two units vertical in 12 units horizontal.
- Attic spaces served by stairways other than the pull-down type shall be designed to support the minimum live load specified for habitable attics and sleeping rooms.
- Areas of occupiable roofs, other than roof gardens and assembly areas, shall be designed for appropriate loads as approved by the building official. Unoccupied landscaped areas of roofs shall be designed in accordance with Section 1607.12.3.1.
- Live load reduction is not permitted unless specific exceptions of Section 1607.10 apply.
- A uniform live load, L, as specified below. This load shall not be reduced.
- 40 psf (1.92 kN/m2) where the design basis helicopter has a maximum take-off weight of 3,000 pounds (13.35 kN) or less.
- 60 psf (2.87 kN/m2) where the design basis helicopter has a maximum take-off weight greater than 3,000 pounds (13.35 kN).
- 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.
- The actual operational loads, including outrigger reactions and contact areas of the vehicles as stipulated and approved by the building official; or
- The live loading specified in Section 1607.7.1.
- For one- and two-family dwellings, only the single concentrated load required by Section 1607.8.1.1 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).
(Equation 16-23) |
For SI: |
L | = | Reduced design live load per square foot (m2) of area supported by the member. |
Lo | = | Unreduced design live load per square foot (m2) of area supported by the member (see Table 1607.1). |
KLL | = | Live load element factor (see Table 1607.10.1). |
AT | = | Tributary area, in square feet (m2). |
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 |
All other members not identified above including:
|
1 |
- The live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent, but the live load shall not be less than L as calculated in Section 1607.10.1.
- 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.
- A reduction shall not be permitted where the live load exceeds 100 psf (4.79 kN/m2) except that the design live load for members supporting two or more floors is permitted to be reduced by a maximum of 20 percent.
Exception: 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.
- 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 a maximum of 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 16-24.
- For one-way slabs, the area, A, for use in Equation 16-24 shall not exceed the product of the slab span and a width normal to the span of 0.5 times the slab span.
R = 0.08(A — 150) | (Equation 16-24) |
For SI: R = 0.861(A — 13.94)
Such reduction shall not exceed the smallest of:- 40 percent for horizontal members;
- 60 percent for vertical members; or
- R as determined by the following equation.
R = 23.1(1+ D/Lo) | (Equation 16-25) |
where:
A | = | Area of floor supported by the member, square feet (m2). |
D | = | Dead load per square foot (m2) of area supported. |
Lo | = | Unreduced live load per square foot (m2) of area supported. |
R | = | Reduction in percent. |
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).
Lr = Lo R1R2 | (Equation 16-26) |
where: 12 ≤ Lr≤ 20
For SI: Lr = Lo R1R2
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:
R1 = 1 for At ≤ 200 square feet (18.58 m2) | (Equation 16-27) |
R1 = 1.2 - 0.001Atfor 200 square feet < At< 600 square feet |
(Equation 16-28) |
For SI: 1.2 - 0.011At for 18.58 square meters < At< 55.74 square meters
R1 = 0.6 for At ≥ 600 square feet (55.74 m2) | (Equation 16-29) |
At | = | Tributary area (span length multiplied by effective width) in square feet (m2) supported by the member, and |
R2= 1 for F ≤ 4 | (Equation 16-30) |
R2= 1.2 - 0.05 F for 4 < F < 12 | (Equation 16-31) |
R2= 0.6 for F ≥ 12 | (Equation 16-32) |
F | = | For a sloped roof, the number of inches of rise per foot (for SI: F = 0.12 × slope, with slope expressed as a percentage), or for an arch or dome, the rise-to-span ratio multiplied by 32. |
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 |
- A horizontal distributed load of 5 psf (0.24 kN/m2) 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.
LOCATION | POUNDS PER SQUARE FOOT |
---|---|
Adak | 30 |
Anchorage | 50 |
Angoon | 70 |
Barrow | 25 |
Barter Island | 35 |
Bethel | 40 |
Big Delta | 50 |
Cold Bay | 25 |
Cordova | 100 |
Fairbanks | 60 |
Fort Yukon | 60 |
Galena | 60 |
Gulkana | 70 |
Homer | 40 |
Juneau | 60 |
Kenai | 70 |
Kodiak | 30 |
Kotzebue | 60 |
McGrath | 70 |
Nenana | 80 |
Nome | 70 |
Palmer | 50 |
Petersburg | 150 |
St. Paul Islands | 40 |
Seward | 50 |
Shemya | 25 |
Sitka | 50 |
Talkeetna | 120 |
Unalakleet | 50 |
Valdez | 160 |
Whittier | 300 |
Wrangell | 60 |
Yakutat | 150 |
GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)
ULTIMATE DESIGN WIND SPEEDS, VULT, FOR RISK CATEGORY II BUILDINGS AND OTHER STRUCTURES
ULTIMATE DESIGN WIND SPEEDS, VULT, FOR RISK CATEGORY III AND IV BUILDINGS AND OTHER STRUCTURES
ULTIMATE DESIGN WIND SPEEDS, VULT, FOR RISK CATEGORY I BUILDINGS AND OTHER STRUCTURES
- Subject to the limitations of Section 1609.1.1.1, the provisions of ICC 600 shall be permitted for applicable Group R-2 and R-3 buildings.
- Subject to the limitations of Section 1609.1.1.1, residential structures using the provisions of AF&PA WFCM.
- Subject to the limitations of Section 1609.1.1.1, residential structures using the provisions of AISI S230.
- Designs using NAAMM FP 1001.
- Designs using TIA-222 for antenna-supporting structures and antennas, provided 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 Chapter 31 of ASCE 7.
- 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; and
- 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 1 mile (1.61 km), whichever is greater.
- Glazed openings located within 30 feet (9144 mm) of grade shall meet the requirements of the large missile test of ASTM E 1996.
- Glazed openings located more than 30 feet (9144 mm) above grade shall meet the provisions of the small missile test of ASTM E 1996.
- 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 one- and two-story buildings classified as 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 1609.1.2 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 1609.3.1 does not exceed 140 mph (63 m/s).
- Glazing in Risk Category I buildings as defined in Section 1604.5, 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.
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 |
- 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 a minimum of 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 a minimum of 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.
6.2.2 Unless otherwise specified, select the wind zone based on the strength design wind speed, Vult, as follows:
6.2.2.1 Wind Zone 1—130 mph ≤ ultimate design wind speed, Vult< 140 mph.
6.2.2.2 Wind Zone 2—140 mph ≤ ultimate design wind speed, Vult< 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 (58 m/s) ≤ ultimate design wind speed, Vult ≤ 160 mph (63 m/s), or 140 mph (54 m/s) ≤ ultimate design wind speed, Vult ≤ 160 mph (63 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— ultimate design wind speed, Vult >160 mph (63 m/s).
In nonhurricane-prone regions, when the ultimate design wind speed, Vult, is estimated from regional climatic data, the ultimate design wind speed, Vult, shall be determined in accordance with Section 26.5.3 of ASCE 7.
(Equation 16-33) |
Vasd | = | nominal design wind speed applicable to methods specified in Exceptions 1 through 5 of Section 1609.1.1. |
Vult | = | ultimate design wind speeds determined from Figures 1609A, 1609B or 1609C. |
Vult | 100 | 110 | 120 | 130 | 140 | 150 | 160 | 170 | 180 | 190 | 200 |
Vasd | 78 | 85 | 93 | 101 | 108 | 116 | 124 | 132 | 139 | 147 | 155 |
- Linear interpolation is permitted.
- Vasd = nominal design wind speed applicable to methods specified in Exceptions 1 through 5 of Section 1609.1.1.
- Vult = ultimate design wind speeds determined from Figures 1609A, 1609B, or 1609C.
Urban and suburban areas, wooded areas or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger.
Open terrain with scattered obstructions having heights generally less than 30 feet (9144 mm). This category includes flat open country, and grasslands.
Flat, unobstructed areas and water surfaces. This category includes smooth mud flats, salt flats and unbroken ice.
Asphalt shingles installed over a roof deck complying with Section 1609.5.1 shall comply with the wind-resistance requirements of Section 1507.2.7.1.
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 1711.2. |
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 27.3.2 of ASCE 7. |
- 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 which 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 at least two-thirds of the tile's area free of mortar or adhesive contact.
- The building or other structure is less than or equal to 75 feet (22 860 mm) in height with a height-to-least-width ratio of 4 or less, or the building or other structure has a fundamental frequency greater than or equal to 1 hertz.
- The building or other structure is not sensitive to dynamic effects.
- The building or other structure is not located on a site for which channeling effects or buffeting in the wake of upwind obstructions warrant special consideration.
- The building shall meet the requirements of a simple diaphragm building as defined in ASCE 7 Section 26.2, where wind loads are only transmitted to the main windforce-resisting system (MWFRS) at the diaphragms.
- For open buildings, multispan gable roofs, stepped roofs, sawtooth roofs, domed roofs, roofs with slopes greater than 45 degrees (0.79 rad), solid free-standing walls and solid signs, and rooftop equipment, apply ASCE 7 provisions.
Cnet | = | Net-pressure coefficient based on Kd [(G) (Cp) - (GCpi)], in accordance with Table 1609.6.2. |
G | = | Gust effect factor for rigid structures in accordance with ASCE 7 Section 26.9.1. |
Kd | = | Wind directionality factor in accordance with ASCE 7 Table 26-6. |
Pnet | = | Design wind pressure to be used in determination of wind loads on buildings or other structures or their components and cladding, in psf (kN/m2). |
STRUCTURE OR PART THEREOF |
DESCRIPTION | Cnet FACTOR | ||||
---|---|---|---|---|---|---|
1. Main windforce- resisting frames and systems |
Walls: |
Enclosed
|
Partially enclosed
|
|||
+ Internal
pressure |
- Internal
pressure |
+ Internal
pressure |
- Internal
pressure |
|||
Windward wall |
0.43
|
0.73
|
0.11
|
1.05
|
||
Leeward wall |
-0.51
|
-0.21
|
-0.83
|
0.11
|
||
Sidewall |
-0.66
|
-0.35
|
-0.97
|
-0.04
|
||
Parapet wall | Windward |
1.28
|
1.28
|
|||
Leeward |
-0.85
|
-0.85
|
||||
Roofs: |
Enclosed
|
Partially enclosed
|
||||
Wind perpendicular to ridge |
+ Internal
pressure |
- Internal
pressure |
+ Internal
pressure |
- Internal
pressure |
||
Leeward roof or flat roof |
-0.66
|
-0.35
|
-0.97
|
-0.04
|
||
Windward roof slopes: | ||||||
Slope < 2:12 (10°) |
Condition 1
|
-1.09
|
-0.79
|
-1.41
|
-0.47
|
|
Condition 2
|
-0.28
|
0.02
|
-0.60
|
0.34
|
||
Slope = 4:12 (18°) |
Condition 1
|
-0.73
|
-0.42
|
-1.04
|
-0.11
|
|
Condition 2
|
-0.05
|
0.25
|
-0.37
|
0.57
|
||
Slope = 5:12 (23°) |
Condition 1
|
-0.58
|
-0.28
|
-0.90
|
0.04
|
|
Condition 2
|
0.03
|
0.34
|
-0.29
|
0.65
|
||
Slope = 6:12 (27°) |
Condition 1
|
-0.47
|
-0.16
|
-0.78
|
0.15
|
|
Condition 2
|
0.06
|
0.37
|
-0.25
|
0.68
|
||
Slope = 7:12 (30°) |
Condition 1
|
-0.37
|
-0.06
|
-0.68
|
0.25
|
|
Condition 2
|
0.07
|
0.37
|
-0.25
|
0.69
|
||
Slope = 9:12 (37°) |
Condition 1
|
-0.27
|
0.04
|
-0.58
|
0.35
|
|
Condition 2
|
0.14
|
0.44
|
-0.18
|
0.76
|
||
Slope = 12:12 (45°) |
0.14
|
0.44
|
-0.18
|
0.76
|
||
Wind parallel to ridge and flat roofs |
-1.09
|
-0.79
|
-1.41
|
-0.47
|
||
Nonbuilding Structures: Chimneys, Tanks and Similar Structures: | ||||||
h/D
|
||||||
1
|
7
|
25
|
||||
Square (Wind normal to face) |
0.99
|
1.07
|
1.53
|
|||
Square (Wind on diagonal) |
0.77
|
0.84
|
1.15
|
|||
Hexagonal or Octagonal |
0.81
|
0.97
|
1.13
|
|||
Round |
0.65
|
0.81
|
0.97
|
|||
Open signs and lattice frameworks |
Ratio of solid to gross area
|
|||||
< 0.1
|
0.1 to 0.29
|
0.3 to 0.7
|
||||
Flat |
1.45
|
1.30
|
1.16
|
|||
Round |
0.87
|
0.94
|
1.08
|
|||
2. Components and cladding not in areas of discontinuity— roofs and overhangs |
Roof elements and slopes |
Enclosed
|
Partially enclosed
|
|||
Gable of hipped configurations (Zone 1) |
|
|
||||
Flat < Slope < 6:12 (27°) See ASCE 7 Figure 30.4-2B Zone 1 |
|
|
||||
Positive |
10 square feet or less
|
0.58
|
0.89
|
|||
100 square feet or more
|
0.41
|
0.72
|
||||
Negative |
10 square feet or less
|
-1.00
|
-1.32
|
|||
100 square feet or more
|
-0.92
|
-1.23
|
||||
Overhang: Flat < Slope < 6:12 (27°) See ASCE 7 Figure 30.4-2A Zone 1 | ||||||
Negative |
10 square feet or less
|
-1.45
|
||||
100 square feet or more
|
-1.36
|
|||||
500 square feet or more
|
-0.94
|
|||||
6:12 (27°) < Slope < 12:12 (45°) See ASCE 7 Figure 30.4-2C Zone 1 | ||||||
Positive |
10 square feet or less
|
0.92
|
1.23
|
|||
100 square feet or more
|
0.83
|
1.15
|
||||
Negative |
10 square feet or less
|
-1.00
|
-1.32
|
|||
100 square feet or more
|
-0.83
|
-1.15
|
||||
Monosloped configurations (Zone 1) |
Enclosed
|
Partially enclosed
|
||||
Flat < Slope < 7:12 (30°) See ASCE 7 Figure 30.4-5B Zone 1 | ||||||
Positive |
10 square feet or less
|
0.49
|
0.81
|
|||
100 square feet or more
|
0.41
|
0.72
|
||||
Negative |
10 square feet or less
|
-1.26
|
-1.57
|
|||
100 square feet or more
|
-1.09
|
-1.40
|
||||
Tall flat-topped roofs h > 60 feet |
Enclosed
|
Partially enclosed
|
||||
Flat < Slope < 2:12 (10°) (Zone 1) See ASCE 7 Figure 30.8-1 Zone 1 | ||||||
Negative |
10 square feet or less
|
-1.34
|
-1.66
|
|||
500 square feet or more
|
-0.92
|
-1.23
|
||||
3. Components and cladding in areas of discontinuities— roofs and overhangs |
Gable or hipped configurations at ridges, eaves and rakes (Zone 2) | |||||
Flat < Slope < 6:12 (27°) See ASCE 7 Figure 30.4-2B Zone 2 | ||||||
Positive |
10 square feet or less
|
0.58
|
0.89
|
|||
100 square feet or more
|
0.41
|
0.72
|
||||
Negative |
10 square feet or less
|
-1.68
|
-2.00
|
|||
100 square feet or more
|
-1.17
|
-1.49
|
||||
Overhang for Slope Flat < Slope < 6:12 (27°) See ASCE 7 Figure 30.4-2B Zone 2 | ||||||
Negative |
10 square feet or less
|
-1.87
|
||||
100 square feet or more
|
-1.87
|
|||||
6:12 (27°) < Slope < 12:12 (45°) Figure 30.4-2C |
Enclosed
|
Partially enclosed
|
||||
Positive |
10 square feet or less
|
0.92
|
1.23
|
|||
100 square feet or more
|
0.83
|
1.15
|
||||
Negative |
10 square feet or less
|
-1.17
|
-1.49
|
|||
100 square feet or more
|
-1.00
|
-1.32
|
||||
Overhang for 6:12 (27°) < Slope < 12:12 (45°) See ASCE 7 Figure 30.4-2C Zone 2 | ||||||
Negative |
10 square feet or less
|
-1.70
|
||||
500 square feet or more
|
-1.53
|
|||||
Monosloped configurations at ridges, eaves and rakes (Zone 2) | ||||||
Flat < Slope < 7:12 (30°) See ASCE 7 Figure 30.4-5B Zone 2 | ||||||
Positive |
10 square feet or less
|
0.49
|
0.81
|
|||
100 square feet or more
|
0.41
|
0.72
|
||||
Negative |
10 square feet or less
|
-1.51
|
-1.83
|
|||
100 square feet or more
|
-1.43
|
-1.74
|
||||
Tall flat topped roofs h > 60 feet |
Enclosed
|
Partially enclosed
|
||||
Flat < Slope < 2:12 (10°) (Zone 2) See ASCE 7 Figure 30.8-1 Zone 2 | ||||||
Negative |
10 square feet or less
|
-2.11
|
-2.42
|
|||
500 square feet or more
|
-1.51
|
-1.83
|
||||
Gable or hipped configurations at corners (Zone 3) See ASCE 7 Figure 30.4-2B Zone 3 | ||||||
Flat < Slope < 6:12 (27°) |
Enclosed
|
Partially enclosed
|
||||
Positive |
10 square feet or less
|
0.58
|
0.89
|
|||
100 square feet or more
|
0.41
|
0.72
|
||||
Negative |
10 square feet or less
|
-2.53
|
-2.85
|
|||
100 square feet or more
|
-1.85
|
-2.17
|
||||
Overhang for Slope Flat < Slope < 6:12 (27°) See ASCE 7 Figure 30.4-2B Zone 3 | ||||||
Negative |
10 square feet or less
|
-3.15
|
||||
100 square feet or more
|
-2.13
|
|||||
6:12 (27°) < 12:12 (45°) See ASCE 7 Figure 30.4-2C Zone 3 | ||||||
Positive |
10 square feet or less
|
0.92
|
1.23
|
|||
100 square feet or more
|
0.83
|
1.15
|
||||
Negative |
10 square feet or less
|
-1.17
|
-1.49
|
|||
100 square feet or more
|
-1.00
|
-1.32
|
||||
Overhang for 6:12 (27°) < Slope < 12:12 (45°) |
Enclosed
|
Partially enclosed
|
||||
Negative |
10 square feet or less
|
-1.70
|
||||
100 square feet or more
|
-1.53
|
|||||
Monosloped Configurations at corners (Zone 3) See ASCE 7 Figure 30.4-5B Zone 3 | ||||||
Flat < Slope < 7:12 (30°) | ||||||
Positive |
10 square feet or less
|
0.49
|
0.81
|
|||
100 square feet or more
|
0.41
|
0.72
|
||||
Negative |
10 square feet or less
|
-2.62
|
-2.93
|
|||
100 square feet or more
|
-1.85
|
-2.17
|
||||
Tall flat topped roofs h > 60 feet |
Enclosed
|
Partially enclosed
|
||||
Flat < Slope < 2:12 (10°) (Zone 3) See ASCE 7 Figure 30.8-1 Zone 3 | ||||||
Negative |
10 square feet or less
|
-2.87
|
-3.19
|
|||
500 square feet or more
|
-2.11
|
-2.42
|
||||
4. Components and cladding not in areas of discontinuity— walls andparapets |
Wall Elements: h ≤ 60 feet (Zone 4) ASCE 7 Figure 30.4-1 |
Enclosed
|
Partially enclosed
|
|||
Positive |
10 square feet or less
|
1.00
|
1.32
|
|||
500 square feet or more
|
0.75
|
1.06
|
||||
Negative |
10 square feet or less
|
-1.09
|
-1.40
|
|||
500 square feet or more
|
-0.83
|
-1.15
|
||||
Wall Elements: h > 60 feet (Zone 4) ASCE 7 Figure 30.6-1 | ||||||
Positive |
20 square feet or less
|
0.92
|
1.23
|
|||
500 square feet or more
|
0.66
|
0.98
|
||||
Negative |
20 square feet or less
|
-0.92
|
-1.23
|
|||
500 square feet or more
|
-0.75
|
-1.06
|
||||
Parapet Walls | ||||||
Positive |
2.87
|
3.19
|
||||
Negative |
-1.68
|
-2.00
|
||||
5. Components and cladding in areas of discontinuity—walls and parapets |
Wall elements: h ≤ 60 feet (Zone 5) Figure 30.4-1 |
Enclosed
|
Partially enclosed
|
|||
Positive |
10 square feet or less
|
1.00
|
1.32
|
|||
500 square feet or more
|
0.75
|
1.06
|
||||
Negative |
10 square feet or less
|
-1.34
|
-1.66
|
|||
500 square feet or more
|
-0.83
|
-1.15
|
||||
Wall elements: h > 60 feet (Zone 4) ASCE 7 Figure 30.6-1 | ||||||
Positive |
20 square feet or less
|
0.92
|
1.23
|
|||
500 square feet or more
|
0.66
|
0.98
|
||||
Negative |
20 square feet or less
|
-1.68
|
-2.00
|
|||
500 square feet or more
|
-1.00
|
-1.32
|
||||
Parapet walls | ||||||
Positive |
3.64
|
3.95
|
||||
Negative |
-2.45
|
-2.76
|
- Linear interpolation between values in the table is permitted.
- Some Cnet values have been grouped together. Less conservative results may be obtained by applying ASCE 7 provisions.
Pnet= 0.00256V2KzCnetKzt | (Equation 16-35) |
- For the windward side of a structure, Kzt and Kz shall be based on height z.
- For leeward and sidewalls, and for windward and leeward roofs, Kzt and Kz shall be based on mean roof height h.
- The pressure coefficient, Cnet, for walls and roofs shall be determined from Table 1609.6.2.
- Where Cnet has more than one value, the more severe wind load condition shall be used for design.
- Calculated pressures at local discontinuities acting over specific edge strips or corner boundary areas.
- Include "field" (Zone 1, 2 or 4, as applicable) pressures applied to areas beyond the boundaries of the areas of discontinuity.
- Where applicable, the calculated pressures at discontinuities (Zone 2 or 3) shall be combined with design pressures that apply specifically on rakes or eave overhangs.
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 |
- 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 D 2487.
R = 5.2(ds + dh) | (Equation 16-36) |
For SI: R = 0.0098(ds + dh)
where:
dh | = | Additional depth of water on the undeflected roof above the inlet of secondary drainage system at its design flow (i.e., 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 (i.e., the static head), in inches (mm). |
R | = | Rain load on the undeflected roof, in psf (kN/m2). When 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. |
100-YEAR, 1-HOUR RAINFALL (INCHES) WESTERN UNITED STATES
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES
100-YEAR, 1-HOUR RAINFALL (INCHES) EASTERN UNITED STATES
100-YEAR, 1-HOUR RAINFALL (INCHES) ALASKA
100-YEAR, 1-HOUR RAINFALL (INCHES) HAWAII
VELOCITY WAVE ACTION.
- Obtain and reasonably utilize any design flood elevation and floodway data available from a federal, state or other source; or
- Determine the design flood elevation and/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.
- For construction in flood hazard areas not subject to high-velocity wave action:
- The elevation of the lowest floor, including the basement, as required by the lowest floor elevation inspection in Section 110.3.3.
- 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 2.6.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.6.2.2 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.
- For construction in flood hazard areas subject to high-velocity wave action:
- The elevation of the bottom of the lowest horizontal structural member as required by the lowest floor elevation inspection in Section 110.3.3.
- 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.
- Detached one- and two-family dwellings, assigned to Seismic Design Category A, B or C, or located where the mapped short-period spectral response acceleration, SS, is less than 0.4 g.
- The seismic force-resisting system of wood-frame buildings that conform to the provisions of Section 2308 are not required to be analyzed as specified in this section.
- Agricultural storage structures intended only for incidental human occupancy.
- Structures that require special consideration of their response characteristics and environment that are not addressed by this code or ASCE 7 and for which other regulations provide seismic criteria, such as vehicular bridges, electrical transmission towers, hydraulic structures, buried utility lines and their appurtenances and nuclear reactors.
RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) GROUND MOTION RESPONSE ACCELERATIONS
FOR THE CONTERMINOUS UNITED STATES OF 0.2-SECOND SPECTRAL RESPONSE ACCELERATION
(5% OF CRITICAL DAMPING), SITE CLASS B
RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) GROUND MOTION RESPONSE ACCELERATIONS
FOR THE CONTERMINOUS UNITED STATES OF 1-SECOND SPECTRAL RESPONSE ACCELERATION
(5% OF CRITICAL DAMPING), SITE CLASS B
(continued)
RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) GROUND MOTION RESPONSE ACCELERATIONS
FOR THE CONTERMINOUS UNITED STATES OF 1-SECOND SPECTRAL RESPONSE ACCELERATION
(5% OF CRITICAL DAMPING), SITE CLASS B
RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) GROUND MOTION RESPONSE ACCELERATIONS
FOR HAWAII OF 0.2- AND 1-SECOND SPECTRAL RESPONSE ACCELERATION
(5% OF CRITICAL DAMPING), SITE CLASS B
RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) GROUND MOTION RESPONSE ACCELERATIONS
FOR ALASKA OF 0.2-SECOND SPECTRAL RESPONSE ACCELERATION
(5% OF CRITICAL DAMPING), SITE CLASS B
RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) GROUND MOTION RESPONSE ACCELERATIONS
FOR ALASKA OF 1.0-SECOND SPECTRAL RESPONSE ACCELERATION
(5% OF CRITICAL DAMPING), SITE CLASS B
RISK-TARGETED MAXIMUM CONSIDERED EARTHQUAKE (MCER) GROUND MOTION RESPONSE ACCELERATIONS
FOR PUERTO RICO AND THE UNITED STATES VIRGIN ISLANDS OF 0.2- AND 1-SECOND SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B
SMS = FaSs | (Equation 16-37) |
SM1= FvS1 | (Equation 16-38) |
Fa | = | Site coefficient defined in Table 1613.3.3(1). |
Fv | = | Site coefficient defined in Table 1613.3.3(2). |
SS | = | The mapped spectral accelerations for short periods as determined in Section 1613.3.1. |
S1 | = | The mapped spectral accelerations for a 1-second period as determined in Section 1613.3.1. |
SITE CLASS | MAPPED SPECTRAL RESPONSE ACCELERATION AT SHORT PERIOD | ||||
Ss ≤ 0.25 | Ss = 0.50 | Ss = 0.75 | Ss = 1.00 | Ss ≥ 1.25 | |
A | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
B | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
C | 1.2 | 1.2 | 1.1 | 1.0 | 1.0 |
D | 1.6 | 1.4 | 1.2 | 1.1 | 1.0 |
E | 2.5 | 1.7 | 1.2 | 0.9 | 0.9 |
F | 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 11.4.7 of ASCE 7.
SITE CLASS | MAPPED SPECTRAL RESPONSE ACCELERATION AT 1-SECOND PERIOD | ||||
S1 ≤ 0.1 | S1 = 0.2 | S1 = 0.3 | S1 = 0.4 | S1 ≥ 0.5 | |
A | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
B | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
C | 1.7 | 1.6 | 1.5 | 1.4 | 1.3 |
D | 2.4 | 2.0 | 1.8 | 1.6 | 1.5 |
E | 3.5 | 3.2 | 2.8 | 2.4 | 2.4 |
F | 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 11.4.7 of ASCE 7.
(Equation 16-39) |
(Equation 16-40) |
SMS | = | The maximum considered earthquake spectral response accelerations for short period as determined in Section 1613.3.3. |
SM1 | = | The maximum considered earthquake spectral response accelerations for 1-second period as determined in Section 1613.3.3. |
VALUE OF SDS | RISK CATEGORY | ||
I or II | III | IV | |
SDS < 0.167g | A | A | A |
0.167g ≤ SDS < 0.33g | B | B | C |
0.33g ≤ SDS < 0.50g | C | C | D |
0.50g ≤ SDS | D | D | D |
VALUE OF SD1 | RISK CATEGORY | ||
I or II | III | IV | |
SD1 < 0.067g | A | A | A |
0.067g ≤ SD1 < 0.133g | B | B | C |
0.133g ≤ SD1 < 0.20g | C | C | D |
0.20g ≤ SD1 | D | D | D |
- In each of the two orthogonal directions, the approximate fundamental period of the structure, Ta, in each of the two orthogonal directions determined in accordance with Section 12.8.2.1 of ASCE 7, is less than 0.8 Ts determined in accordance with Section 11.4.5 of ASCE 7.
- In each of the two orthogonal directions, the fundamental period of the structure used to calculate the story drift is less than Ts.
- Equation 12.8-2 of ASCE 7 is used to determine the seismic response coefficient, Cs.
- The diaphragms are rigid as defined in Section 12.3.1 of ASCE 7 or, for diaphragms that are flexible, the distances between vertical elements of the seismic force-resisting system do not exceed 40 feet (12 192 mm).
- The value of RI as defined in Chapter 17 is taken as 1.
- For OMFs and OCBFs, design is in accordance with AISC 341.
LONGITUDINAL, PERIMETER, TRANSVERSE AND VERTICAL TIES
TT = w LS ≤ αTS | (Equation 16-41) |
where:
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. |
Tp= 200w ≤βT | (Equation 16-42) |
For SI: Tp= 90.7w ≤βT
where:
w | = | As defined in Section 1615.4.2.1. |
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. |