多向荷载作用下层状地基刚性桩筏基础分析

提出一种多向荷载作用下层状地基中刚性桩筏基础的计算方法。基于剪切位移法，采用传递矩阵形式分析了竖向荷载下桩顶面-桩顶面相互作用；引入修正桩侧地基模量，采用有限差分法分析了水平荷载下桩顶面-桩顶面相互作用；基于层状弹性半空间理论，分析了多向荷载下桩顶面-土表面、土表面-桩顶面、土表面-土表面的相互作用关系。建立了桩土体系柔度矩阵，得到了多向荷载下层状地基中刚性桩筏基础的受力和变形的关系以及桩的内力和变形沿桩身分布规律。通过与有限元对比，验证了该方法的合理性和修正地基模量的优越性，并对多向荷载作用下的桩筏基础进行了计算分析，计算结果表明，水平力将会引起桩筏基础的倾斜。

Analysis of rigid piled raft foundations subjected to coupled loads in layered soils

A simplified analytical approach is proposed to study the behavior of piled raft foundation with rigid raft subjected to coupled loads in layered soils. Based on the shear displacement method, using the transfer matrix, the pile-pile interaction under vertical load is analyzed. Adopting the modified subgrade modulus, the pile head-pile head interaction under horizontal load is analyzed through the finite difference method. Based on solutions for stress and displacement in layered elastic half space, the interactions between pile head and soil surface, soil surface and pile head, soil surface and soil surface subjected to coupled loads are taken into account to determine the flexibility matrix of the pile group-soil system. Then the load-settlement relationship of rigid piled raft foundations subjected to coupled loads, load and settlement of the piles along the depth are obtained. Comparison between the finite element results and the calculated results is carried out; and the feasibility of the present method for analyzing piled raft foundation and the superiority of the modified subgrade modulus are proved. The piled raft foundation with rigid raft subjected to coupled loads is analyzed. The calculating results indicate that the horizontal load will cause the pile raft foundation oblique.