中文摘要：

在随机过程的正交展开式中,通过构造标准正交随机变量的随机函数形式,建立了非平稳地震动过程的概率模型。在此模型中,利用基本随机变量的离散代表点集,可以直接获取具有给定赋得概率的非平稳地震动过程的代表性样本集合。应用所生成的252条非平稳地震动代表性时程,并考虑地震动峰值加速度均值为0.2 g、0.4 g和0.5 g三种情况,分别对Koyna重力坝进行了地震动力有限元分析。同时,结合概率密度演化方法,给出了坝体结构薄弱部位处的地震反应概率信息和抗震可靠度。

英文摘要：

In the orthogonal expansion formula of stochastic processes,through constructing the form of random function of normalized orthogonal random variables,a new probabilistic model of non-stationary ground motion has been established. In this model,using the discrete representative point set of the basic random variable,the representative samples＇ set of the non-stationary ground motion process can be obtained directly,and each generated representative sample has an assigned probability. According to the peak ground acceleration in three cases of 0.2g,0.4g,0.5g,respectively,252 generated representative samples of non-stationary ground motion are applied to research the seismic dynamic response of the Koyna gravity dam.Further,combining with the probability density evolution method,the probabilistic information of seismic response at the weak parts and seismic reliability of the dam can be obtained,which provides an accurate approach to study stochastic seismic response and reliability analysis of the gravity dam.