Study On Statistical Methods For Selection Of Accerelation Records And Intensity Measures Of Earthquake Ground Motions

The new generation of"Performance-Based Earthquake Engineering (PBEE)"decision-making framework was developed by Pacific Earthquake Engineering Research (PEER) centre, in which uncertainty analysis of ground motion is a main mode. Record-to-record method is often adopted to depict the effect factors on ground motion. How to select reasonable records and intensity measures of ground motion is the core issue.This thesis proposes the concept of"maximum credible ground motion"obtained through incremental dynamic analysis (IDA), and offers the principles to choose the maximum credible ground motion. The ground motion identification procedure consists of: choosing a suitable suite of ground motions and an appropriate intensity measure; selecting a computational tool and modeling the structure accordingly; performing Incremental Dynamic Analysis on a non-linear model of the structure; interpreting these results into 50th (median) and 84th percentile performance bounds; and identifying the credible ground motions that are close to these defining probabilistic curves at ground motion intensities corresponding to the design basis earthquake and the maximum considered earthquake. Forty real ground motion records are selected as input records. Three test-examples of single-degree of freedom (SDOF) with short period, medium long period and long period are built up by NONLIN, and three multiple-degree of freedom (MDOF) corresponding to the SDOFs are generated on OpenSees. Then the maximum credible ground motions of three SDOFs and three MDOFs are obtained conditioned on the design basis intensity and the maximum considered intensity of numerical examples.Thirty six intensity measures (IMs) of ground motion are employed in this thesis, which are calculated utilizing MATLAB according to the forty ground motion records selected. Different statistical characteristics of IMs are analyzed, which include the correlation between IMs and structural damage measures (DMs), the efficiency of IMs, the practicality of IMs, the proficiency of IMs,the sufficiency of IMs and the robustness of IMs. Then the relative optimum IMs for different numerical examples of SDOFs and MDOFs are recommended.