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为分析饱和地基动力反应，讨论了用ｕ－ｐ 格式有限元数值解法。将土视为两相体，考虑水的渗流与土骨架变形的相互影响。引入考虑饱和土两相性情况下的传输边界，用以模拟地基无限性。推导了加入传输边界后的有限元方程，讨论了相应总体方程的无条件稳定交叉求解方法。通过饱和有限厚土层表面受条形简谐荷载作用的算例，对比两种不同的人工边界（自由边界、传输边界），并结合算例讨论了渗透系数对位移和孔压的影响及有限厚土层截止频率的存在和产生机理等有关问题。分析表明当量纲１ 的传输边界距离大于４ 时， 计算精度将满足实用要求； 另外，渗透系数的重要影响也说明了在饱和地基动力计算中考虑渗流的必要性。
In order to analyze the dynamic response of saturated foundations, finite element numerical solutions using u-p format are discussed. Think of the soil as a two-phase body and consider the interaction between water seepage and soil skeleton deformation. The transmission boundary considering the two-phase condition of saturated soil was introduced to simulate the infinite property of the foundation. The finite element equations after adding the transmission boundary are deduced, and the unconditional stable cross-solving method for the corresponding global equation is discussed. An example of the saturated finite-thick soil surface subjected to the simple harmonic loading of strips was used to compare two different artificial boundaries (free boundary and transmission boundary), and the effect of the permeability coefficient on displacement and pore pressure was discussed with an example. The existence of the cut-off frequency of thick soil layers and the production mechanism and other related issues. The analysis shows that the computational accuracy will satisfy the practical requirements when the transmission boundary distance of the equivalent 1 is greater than 4; In addition, the important influence of the permeability coefficient also explains the necessity of considering the seepage in the dynamic calculation of the saturated foundation.