Section 3413A Modifications to ASCE 41
The text of ASCE 41 shall be modified as indicated in Sections 3413A.1.1 through 3413A.1.14.
Modify ASCE 41 Section 1.1 with the following:
Seismic evaluations shall be performed for performance objective specified in Section 3412A of this code (CBC) using procedure of this standard (ASCE 41) as follows:
- Structural components shall be evaluated in accordance with Tier 3 systematic evaluations procedure in Chapter 6.
- Nonstructural components shall be evaluated in accordance with Chapter 13.
Exception: For general acute care hospitals, seismic evaluation shall be permitted to be in accordance with Chapter 6 of the California Administrative Code (CAC) when required by provisions of that chapter.
Modify ASCE 41 Section 2.4 by the following:
Response spectra and acceleration time histories shall be constructed in accordance with Sections 1613A, 1616A, and 1803A.6.
Modify ASCE 41 Section 6.2 with the following:
Data Collection Requirements. The extent of data collection shall be at Comprehensive level for all structures, including structures upgraded to SPC-4D. A testing program for materials properties shall be approved by the enforcement agent prior to commencement of material testing work. Previously approved material test results shall be permitted to be used to satisfy part of the comprehensive data collection requirements.
Exception: Data collection at Usual level shall be permitted for structures with SPC-2 or lower target performance objective.
Tension testing of reinforcing bars shall be in accordance with ASTM A370 Annex A9. All test specimens shall be the full section of the bar as rolled (8-in. gage length) and shall not be reduced.
At test sample locations, structural members, slabs and walls shall be repaired to a state that is equivalent to their original condition.
For buildings built under an OSHPD permit based on the 1976 or later edition of the CBC, where materials properties are shown on design drawings and original materials test data are available, no materials testing shall be required when approved by the enforcement agent.
Modify ASCE 41 Section 22.214.171.124 with the following:
Nonlinear Static Procedure. If higher mode effects are significant and building is taller than 75 feet above the base, the Nonlinear Dynamic Procedure shall be used.
Modify ASCE 41 Section 7.5.1 with the following:
Acceptance Criteria — Drift Limitations. The interstory drift ratio shall not exceed the drift limits for Risk Category IV buildings in ASCE 7 Table 12.12-1 due to forces corresponding to BSE-1E or BSE-1N, as applicable.
Exception: Larger interstory drift ratios shall be permitted where justified by rational analysis that both structural and nonstructural elements can tolerate such drift and approved by the enforcement agent.
Modify ASCE 41 Section 126.96.36.199 by the following:
Material Properties. Expected material properties are not permitted to be determined by multiplying lower bound values by the assumed factors specified in Chapters 8 through 12 and shall be based exclusively on materials tests.
Modify ASCE 41 Section 8.4 with the following:
Foundation Strength and Stiffness. Foundation and soil strength shall be used to evaluate potential overturning, uplift and sliding for fixed base assumptions, and stiffness for flexible base assumptions, including deformations associated with those actions.
Replace ASCE 41 Section 188.8.131.52 as follows:
Prescriptive Expected Capacities. Not permitted by OSHPD.
Modify ASCE 41 Section 8.5 with the following:
The product of RRSbsa x RRSe, shall not be less than 0.7.
The combined effect of kinematic interaction and foundation damping shall meet the following:
- The site specific response spectrum modified for soil-structure interaction effects shall not be taken as less than 80 percent of the spectral acceleration as determined from a site-specific response spectrum in accordance with ASCE 7 Section 21.3, or
Modify ASCE 41 Section 8.6 with the following:
Seismic Earth Pressure. Where the grade difference from one side of the building to another exceeds one-half story height, the seismic increment of earth pressure shall be added to the gravity lateral earth pressure to evaluate the building overturning and sliding stability and the lateral force resisting system below grade in combination with the building seismic forces.
Modify ASCE 41 Section 10.7.1.1 with the following:
Monolithic Reinforced Concrete Shear Walls and Wall Segments. For nonlinear procedures, shear walls or wall segments with axial loads greater than 0.35 Po shall be included in the model as primary elements with appropriate strength and stiffness degrading properties assigned to those components subject to the approval of the enforcement agent. For linear procedures, the effects of deformation compatibility shall be investigated using moment-curvature section analyses and cyclic testing results of similar components to determine whether strengthening is necessary to maintain the gravity load carrying capacity of that component.
Horizontal wall segments or spandrels reinforced similar to vertical wall segments or piers shall be classified as wall segments, not shear wall coupling beams, in Tables 10-19 through 10-22.
Modify ASCE 41 Section 11.1 by the following:
Scope: Unreinforced Masonry walls (including unreinforced infill walls) and partitions are not permitted for General Acute Care (GAC) hospital buildings.
Modify ASCE 41 Section 14.1 by the following:
Scope: For buildings located in Seismic Design Category F, verification of the interstory lateral displacements, the strength adequacy of the seismic force resisting system and anchorage to the foundation shall be accomplished using the Nonlinear Dynamic Procedure.
Not permitted by OSHPD.