场地地震反应非线性分析的有效时域算法

An effective time-domain computational method for nonlinear seismic response analysis of soil deposit

运用笔者所建议的动态应力－应变关系及推广的加卸载准则考虑土料在循环或瞬时加载下的非线性滞回特性，将时域逐渐积分格式与不平衡荷载转移法相结合提出了动力非线性方程的增量－常刚度迭代算法；以水平成层场地一维剪梁模型为例建立了求解土体地震反应的非线性分析技术。针对某土层剖面，运用这种真非线性算法与以往等价线性化法进行了对比计算，讨论了两者之差别。

Dynamic constitutive relationship proposed by the authors, together with the extended Masing's rules,is employed to account for nonlinear hysteretic property of soil material under transient or cyclic loadings. Step-by-step time integration scheme and load transfer method are combined to develop an efficient incrementally-iterative calculating technique for dynamic nonlinear problem. Afterwards, a truly nonlinear analysis procedure is presented and numerically implemented for evaluating seismic response of horizontally-layered soil deposits. Based on numerical computations for a sample problem, a comparative study is performed between the solutions obtained respectively by the truly nonlinear analysis and by the commonly-used equivalent linearization approximation.