考虑饱和两相介质的土层地震反应分析

地下水位以下的饱和土层是两相介质,波在其中传播需要考虑水和土的相互作用。为了考虑饱和土层中水土耦合作用,将饱和两相介质的Biot波动理论引入土层地震反应,用来计算地下水位以下饱和土层的地震反应。在此基础上,采用有限差分法,结合人工透射边界,提出了一种考虑饱和两相介质的土层地震反应分析方法。利用该方法计算了响嘡台阵3^#测井的土层地震反应,并与等效线性化方法计算结果和实际强震记录进行了对比分析。结果表明:该方法和等效线性化方法均可以反映出和实测结果相似的加速度时程和反应谱数据,该方法的理论模型较单相介质方法更合理,计算得到的加速度时程和反应谱数据也更接近真实记录。

Seismic Response Analysis in Consideriation of Saturated Two-phase Medium

Saturated soil layer, located below underground water level, is a two-phase medium(fluid-saturated porous medium). We take into account the interaction between water and soil for wave propagation. In order to consider the coupled effect of soil and water in saturated soil, we introduce Biot’s theory of fluid-saturated porous media to seismic response of soil layer, calculating seismic response of the layer. On the basis of finite difference method and artificial transmitting boundary method, we put forward a method for seismic response analysis for soil layer of two-phase medium. Monitoring well No.3 of Xiangtang array is taken as an example. Furthermore, we use the new method to calculate soil seismic response at the array, and compare the results with results from equivalent linearization method, as well as actual records from intense earthquakes. Results show that both the new method and equivalent linearization method could reflect time-history curves and response spectrum data, which is similar to measured data; theoretical model of the new method is superior to single phase method, with less difference between calculated data and measured data.