目前完全耦合的动力分析方法在液化场地地震响应分析上应用较少,本文利用完全耦合的动力分析方法,模拟了0.15 g和0.5 g加速度输入下的自由液化场地振动台试验以及实际液化场地的地震动变化情况。利用修正的Pastor-Zienkiewicz Mark-III模型来模拟砂土在地震荷载作用下的液化特性,并详细叙述了该模型参数的选取过程。分析结果表明:该方法能够较好模拟液化场地地表加速度和孔压比时程的变化规律,模拟出的地表加速度反应谱在整个频域内与实测的地表加速度反应谱呈现相同的变化规律。同时,也说明了本文选用模型参数方法的合理性。
This paper simulates two shaking table tests performing for ground liquefaction with seismic input of 0.15 g and 0.5 g as well as the Wildlife site where liquefaction was triggered during the Superstition Hills Earthquake, 1987 using a fully coupled dynamic effective stress analysis. A modified generalized plasticity model is used to sim- ulate cyclic mobility and liquefaction behavior of saturated sands. The parameters of the generalized plasticity model are calibrated from laboratory tests and conventional field investigations. The numerical results show that the simu- lated ground acceleration and the history of pore water pressure ratio accord well with the measurements. In addi- tion, the calculated acceleration response spectra for the ground response correspond well with those of the measure- ments. Thus, the used fully coupled dynamic effective stress method is very effective in analyzing seismic response of liquefied site.