Seismic Loss Assessment Of Frame Structures Based On Empirical Data

Performance-based seismic design(PBSD)is an effectively approach to reduce the social and economic losses caused by earthquakes,and it is one of the main fields of future earthquake engineering.In the design process,the results of the performance indicators need to be evaluated through the performance evaluation to link the design plan with the performance objectives.Based on the method introduced by FEMA P-58,the following research contents are completed on an RC frame structure designed following the current Chinese seismic design codes:1.The design parameters that affect the seismic performance of RC frame joints are summarized.The major design specifications are compared between the US and Chinese seismic design codes.The quantification analysis shows that the RC joints designed following US codes exhibit a larger deformability.According to the fragility analysis procedure,the seismic performance category and the select criteria have been established,based on which 15 research papers were selected and 48 valid experimental data were obtained.The fragility probability model is calibrated by the parameter estimation method,and the fitness has been tested.The results show that the lognormal distribution can be used to simulate the fragility function of RC frame joints.2.The fragility of infill walls was studied by using the method similar as that of the RC frame joint.15 research articles were reviewed and 30 valid experimental were obtained by use of the selection criteria of infill walls.The major design parameters are identified and the fragility model was developed also by using of the lognormal distribution.3.A three story RC frame structure was used as an example which was newly built before the Ludian earthquake but seriously damaged during the shake.A finite element model was constructed by PERFORM-3D considering the infill walls.Plastic time history analyses traced the process from the initial damage to the overall collapse observed after the earthquake.It is found from both field reconnaissance and the analysis results that the residual deformation of the structure was obviously increased when the infill wall is taken into account.3 far field ground motions,3 near field pulse-like ground motions,3 near field non pulse ground motions,and the Ludian records were selected as the inputs.The structural demand parameters under different intensity earthquakes are obtained by IDA analysis,and their probabilistic model was established.4.Based on the performance evaluation method of FEMA P-58,the performance model of the target structure is established(including cost of structure,cost and quantity of components),and a structural economic loss calculation program has been built.The seismic economic loss of the structure is evaluated using both the intensity based method and the time based evaluation method.