Seismic Screening, Evaluation, Rehabilitation, and Design Provisions for Wood-Framed Structures

Seismic screening, evaluation, and rehabilitation design of two existing wood-framed structures are performed using FEMA 154, FEMA 356, ASCE/SEI 31, and the 1997 UBC. FEMA 154 screening demonstrates the importance of examining construction drawings. Plans revealed a structural deficiency, but screening alone indicated no further evaluation is needed. Demand-to-capacity ratios for shear walls and roof diaphragms are examined. 1997 UBC design provisions for new buildings are not necessarily conservative compared to FEMA 356 rehabilitation guidelines. Also, FEMA 356 and 1997 UBC design provisions are not necessarily conservative compared to existing building evaluation in ASCE/SEI 31. A likely cause of the unexpected results is the conservative linear static procedure and associated $m$ factors for wood in FEMA 356 and ASCE/SEI 31. Research is needed to better calibrate these factors and acceptance criteria to account for duration of shaking, number of cycles of nonlinear behavior, and redundancy.