中硬场地地震影响系数谱的概率保证

Probability Assurance of Seismic Influence Coefficient Spectra on Medium-Stiff Soil Site

我国抗震规范中采用的是地震影响系数谱,从概率上来研究规范反应谱具有重要意义.采集中硬场地上205条地震记录,研究了反应谱的概率分布模型,并运用K-S检验进行了验证.通过统计分析获得了对数正态分布,研究了规范反应谱的概率保证,发现规范反应谱在某些区段的概率保证仅有20%-30%.在加速度、速度和位移控制段获得不同概率保证的谱曲线,并对规范反应谱进行了调整,依据规范反应谱的形式运用最小二乘法对得出的谱曲线进行了拟合,拟合效果较好.

The research on probability density function of seismic influence coefficient of code for seismic design has great significance.Based on 205 earthquake records collected from the medium-stiff soil site,this paper derived the probability distribution model of response spectra,and it is verified by means of K-S test method.According to lognormal distribution,this paper studies the probability of response spectra of Chinese code which is only 20%~30% in some sections.High frequencies,medium frequencies and low frequencies of response spectra of Chinese code are adjusted and the response spectra curves having different probability in the three sections are given.According to the shape of response spectra of Chinese code,least square method is used to fit spectral curve.