Article 7. Technical Amendments to Structural Standards
19.28.080 Various Technical Amendments to Structural Standards.
1613.8 ASCE 7, Section 12.8.7. ASCE 7, Section 12.8.7, Equation 12.8-16 shall be:
1704.4 Concrete Construction. The special inspections and verifications for concrete construction shall be as required by this section and TABLE 1704.4.
Exceptions: Special inspections shall not be required for:
1. Isolated spread concrete footings of buildings three stories or less above grade plane that are fully supported on earth or rock, where the structural design of the footing is based on a specified compressive strength, f’c, no greater than 2,500 pound per square inch (psi) (17.2 Mpa).
1908.1.8 ACI 318, section 22.10 Plain concrete in structures assigned to seismic design category C, D, E or F.
22.10.1- Structures assigned to Seismic Design Category C, D, E or F shall not have elements of structural plain concrete, except as follows:
(a) Isolated footings of plain concrete supporting pedestals or columns are permitted, provided the projection of the footing beyond the face of the supported member does not exceed the footing thickness.
Exception:
In detached one and two-family dwelling three stories or less in height, the projection of the footing beyond the face of the supported member is permitted to exceed the footing thickness.
(b) Plain concrete footing supporting walls are permitted, provided the footings have at least two continuous longitudinal reinforcing bars. Bars shall not be smaller than No. 4 and shall have a total area of not less than 0.002 times the gross cross-sectional area of the footing. A minimum of one bar shall be provided at the top and bottom of the footing. Continuity of reinforcement shall be provided at corners and intersections.
Exception:
In detached one and two-family dwellings three stories or less in height and constructed with stud bearing walls, plain concrete footings with at least two continuous longitudinal reinforcing bars not smaller than No. 4 are permitted to have a total area of less than 0.002 times the gross cross-sectional area of the footing.
|
CONDITION |
SHEATHING TYPEb |
SDS < 0.50 |
0.50 ≤ SDS < 0.75 |
0.75 ≤ SDS ≤ 1.00 |
SDS > 1.00 |
|---|---|---|---|---|---|
|
One Story |
S-W |
5 feet 4 inches |
8 feet 0 inches |
9 feet 4 inches |
12 feet 0 inches |
a. Minimum length of panel bracing of one face of the wall for S-W sheathing h/w ratio shall not exceed 2:1. For S-W panel bracing of the same material on two faces of the wall, the minimum length is permitted to be one-half the tabulated value but the h/w ratio shall not exceed 2:1 and design for uplift is required.
b. S-W = wood structural panels and diagonal wood sheathing.
(Ord. 7158-NS § 1 (part), 2010)