317.5 Minimum Seismic Design Performance Levels for Structural and Nonstructural Components
Following the notations of ASCE 41, the seismic requirements for design and assessment are based upon a prescribed Earthquake Hazard Level (BSE-1N, BSE-2N, BSE-1E, BSE-R or BSE-C), a specified structural performance level (S-1 through S-5) and a nonstructural performance level (N-A through NE). The minimum seismic performance criteria are given in Table 317.5 according to the Building Regulatory Authority and the Risk Category as determined in Chapter 16 of the California Building Code or by the regulatory authority. The building shall be evaluated in accordance with a Tier 3 Systematic Evaluation and Retrofit per ASCE 41 Chapter 6 for both the Level 1 and Level 2 performance levels, and the more restrictive requirements shall apply.
Exception: If the floor area of an addition is greater than the larger of 50 percent of the floor area of the original building or 1,000 square feet (93 m2), then the Table 317.5 entries for BSE-R (or BSE-1E) and BSE-C are replaced by BSE-1N and BSE-2N, respectively.
SEISMIC PERFORMANCE REQUIREMENTS BY BUILDING REGULATORY AUTHORITY AND RISK CATEGORY.
|Building Regulatory Authority||Risk Category||PERFORMANCE CRITERIA|
|Level 1||Level 2|
|State-Owned [BSC]||I, II, III||BSE-R, S-3, N-C||BSE-C, S-5, N-D|
|State-Owned [BSC]||IV||BSE-R, S-2, N-B||BSE-C, S-4, N-D|
|Division of the State Architect - [DSA-SS]||I||BSE-1N, S-3, N-B||BSE-2N, S-5, N-D|
|Division of the State Architect - [DSA-SS]||II, III||BSE-1N, S-2, N-B||BSE-2N, S-4, N-D|
|Division of the State Architect - [DSA-SS]||IV||BSE-1N, S-2, N-A||BSE-2N, S-4, N-D|
|Division of the State Architect - [DSA-SS/CC]||I, II||BSE-1E, S-3, N-C||BSE-2N, S-5, N-D|
|Division of the State Architect - [DSA-SS/CC]||III||BSE-1E, S-3, N-B||BSE-2N, S-5, N-D|
|Division of the State Architect - [DSA-SS/CC]||IV||BSE-1E, S-2, N-B||BSE-2N, S-4, N-D|
- ASCE 41 provides acceptance criteria (e.g., m, rotation) for Immediate Occupancy (S1), Life Safety (S3), and Collapse Prevention (S5), and specifies in Sections 18.104.22.168.1 and 22.214.171.124.1 the method to interpolate values for S-2 and S-4, respectively. For nonstructural components, N-A corresponds to the Operational level, N-B to the Position Retention, N-C to the Life Safety level, N-D to the Hazards Reduced, and N-E to the Not Considered. When evaluating for the Hazards Reduced Nonstructural Performance Level, the requirements need not be greater than what would be required by ASCE 7 nonstructural provisions for new construction.
- Buildings evaluated and retrofitted to meet the requirements for a new building, Chapter 16 of the California Building Code, in accordance with the exception in Section 319.1, are deemed to meet the seismic performance requirements of this section.