【摘要】 基于有限压缩层地基模型和Reissner板的边界积分方程,考虑柱荷载作用区域的形状和筏板的横向剪切变形效应,建立了有限压缩层地基上厚筏基础与地基相互作用分析的边界元方程和系统的数值方法。对于弹性半空间模型,其柔度方程可视为有限压缩层模型的特殊情况。把筏板作为自由边界条件处理,被剖分为一系列三角形或矩形网格,假设基底反力在网格内均匀分布,以便与现有的地基沉降计算模式相一致。计算表明,虽然基底反力在内部网格相接处不连续,但并不影响计算结果,反而消除了边界基底压力计算值过大的现象。将该方法与其他方法的计算结果进行比较,显示了该方法的有效性。计算结果表明,对于实际复杂的筏板基础,无需划分太多单元即可得到较高的计算精度。更多还原

【Abstract】 Based on the model of finite compressible strata and boundary element method of Reissner’s plate beading problem,the modified integral equations and a general numerical method on the interaction of raft foundations with the finite compressible strata are presented,in which the shape of columns loading and the effect of transverse shear deformation in the raft are considered.For elastic half-space model,the flexibility equations can be obtained by regarding as a special case of the finite compressible strata model.The raft is treated as thick plate with free edge boundary conditions,and is discretized by a series of triangular or rectangular domain cells or elements,the subgrade reaction is assumed as uniformly distribution in each cell,and thus is consistent with the computing settlement methods now.The numerical results show that the excessively high computing values of the subgrade reaction on the edges of raft are avoided by using the discontinuous bearing pressure distribution at cell conjunctions,which have little influence on the computing results.The presented numerical results,which use finite compressible strata model and elastic half-space model respectively,are compared with those previous researchers.It is shown that higher accurate results can be obtained even with a few numbers of boundary elements and internal cells for practical complex raft foundation.更多还原