Probability-based Seismic Performance Evaluation Of Structure Under Near-fault Ground Motion

Earthquake is a devastating natural disaster. The recent strong earthquakes resulted in great personal casualty and financial loss, so the evaluation of structural seismic performance begins to attract people's attention and becomes an important field of earthquake engineering. The recent earthquakes also shows that the the earthquake ground motion near fault is more devastating than ordinary earthquake ground motion and distinctly different from ordinary earthquake. Therefore, the seismic performance evluation of structures under near-fault ground motion becomes attention-getting in earthquake engineering.Based on the theory of probability-based seismic performance evaluation, Autor studied the seismic performance evluation of structures under near-fault ground motion. The selection of intensity measure of near-fault ground motion, probabilistic seismic hazard analysis of near-fault ground motion, the incremental dynamic analysis of structures subjected to near-fault ground motion and probabilistic seismic demand analysis of structues under near-fault ground motion were mainly discussed in this paper. The main points were as follows:(1) The elastic response spectral acceleration was regarded as the intensity measure of near-fault ground motion and the attenuation model of response spectral acceleration was studied. The prediction variable and the form of attenuation model were determined firstly, and the attenuation model was established by using stepwise regression and multiple linear regression method. The prediction model of standard deviation was also established by using linear regression. The attenuation model of elastic response spectral acceleration is the base of the attenuation model of inelastic response spectral displacement.(2) The efficency of inelastic response spectral displacement used as the intensity measure of pulse-type near-fault ground motion to predict seismic response of structure was studied, and the parameter determination of nonlinear oscillator were also studied. The applicability of inelastic response spectral displacement used as the intensity measure of near-fault ground motion in terms of probability-based seismic performance evaluation was studied.(3) The seismic hazard of site was studied by using inelastic response spectral displacement as the intensity measure of ground motion. The influences of pulse period and strength reduction factor on inelastic response spectral displacement were observed. And the attenuation model of inelastic response spectral displacement was studied. By using the attenuation model of elastic response spectral acceleration proposed by author, the attenuation model of inelastic response spectral displacement of near-fault ground motion was proposed and the method of seismic hazard analysis of near-fault site was also proposed.(4) The incremental dynamic analysis was performed by using inelastic response spectral displacement as the intensity measure of near-fault ground motion. The results of increatmental dynamic analysis of pulse-type near-fault ground motion and ordinary near-fault ground motion were compared, and the incremental dynamic analysis by using inelastic response spectral displacement was studied.(5) The process of evaluating seismic performance of structures under near-fault ground motion by using inelastic response spectral displacement was proposed, and several examples were performed.