Report - PEER - University of California, Berkeley

(1) Experience of a damaging earthquake makes the engineers to set higher seismicperformance levels. The group who experienced 1995 Kobe earthquakerecognized the importance of strong involvement in determination of the seismicperformance levels including appropriate investment level, instead of only doingtheir best within a given boundary conditions.(2) The experience of Kobe earthquake affects the estimate of actual period of repair.The group who experienced Kobe earthquake estimated the actual repair periodlonger than the group who did not experience Kobe earthquake.(3) Based on the current technology, it is not possible to take account of thedifference of demands for accessible time between “within a week” and “within 3weeks” in design. We need a breakthrough technology which enables toincorporate realistic demands in design.(4) There exist large scatterings in the estimate of cost increase which is required toconstruct bridges which are free from any closure to traffic (damage-free bridges).How much cost can be validated for repair had large scattering in replies from theengineers. Realistic evaluation on the initial cost and repair cost is important toset clearer performance goals.(5) In the performance-based seismic design, the engineers expect to make designrational by setting the performance criteria depending on bridges. Littleexpectation was directed to use the most favorable analytical models and tools.(6) The engineers intend to use dynamic response analysis more extensively in theperformance-based seismic design. About a half engineers want to use dynamicresponse analysis for bridges to which pushover analysis is poor, whileapproximately a quarter engineers intend to use dynamic response analysisinstead of pushover analysis because the input data for dynamic response analysisare nearly the same with the input data for pushover analysis(7) The engineers pointed out that higher engineering background, knowledge andskill required for engineers is the largest barrier for the seismic performancebaseddesign. They also pointed out problems that design is controlled by only adesigner or a design group with high technological background, and risk andresponsibility increase in the performance-based seismic design.REFERENCESArakawa, T., and K. Kawashima. (1986). Dependence of construction cost of bridgeson the lateral force coefficient. Civil Engineering Journal. 28(2): 64-69.Japan Association for Earthquake Engineering. (2004). Current state and futureproblems of the performance-based seismic design of structures, ResearchCommittee on Performance-based Seismic Design.88