论文部分内容阅读
对地震作用下饱和砂土的孔隙压力和残余变形,作者曾根据孔隙水封闭在骨架中的假定提出一个有限单元的计算方法.本文将考虑孔隙水压力的扩散和消散,对饱和砂土同时进行动力渗流和变形计算. 整个计算过程分为地震阶段和震后阶段,每个阶段再划分若干时段.在第一个阶段中,每个时段需要同时进行动力反应分析及静力计算,震后阶段只进行静力计算.动力计算采用非线性等价粘弹性体模式.动力剪切模量和阻尼系数按修正后的哈丁(Hardin)等人的经验公式计算,并考虑动压应力与动剪应力的共同作用.文中建议了一组计算动力作用下残余体积应变和残余剪切应变增量的经验公式.静力计算按皮奥(Biot)固结理论同样的办法处理,并用初应变法把应变增量化为结点力. 作为算例,文末给出了砂层水平振动的计算结果.
For the pore pressure and residual deformation of saturated sand under seismic action, the author has proposed a finite element calculation method based on the assumption that the pore water is enclosed in the skeleton. This article will consider the diffusion and dissipation of pore water pressure, and simultaneously perform the saturated sand. Dynamic seepage and deformation calculations. The entire calculation process is divided into earthquake stage and post-earthquake stage, and each stage is divided into several periods. In the first stage, dynamic response analysis and static calculation need to be performed at the same time in each stage. Only static calculations are used. The dynamic calculation uses a non-linear equivalent viscoelastic body model. The dynamic shear modulus and damping coefficient are calculated according to the modified Hardin et al. empirical formula, and dynamic pressure stress and dynamic shear are considered. The joint action of stress. This paper proposes a set of empirical formulas for calculating the residual volumetric strain and the residual shear strain increment under dynamic action. The static calculation is treated in the same way as the Biot consolidation theory, and the initial strain method is used. The strain is increased to the node force. As an example, the calculation result of the horizontal vibration of the sand is given at the end of the paper.