高层建筑桩筏基础中筏板受力数值模拟研究

摘要

建立了粉煤灰地基上高层建筑-桩筏基础-地基共同作用的数值分析模型，通过模拟不同距径比和桩长的桩筏基础，研究了筏板的受力响应问题。数值模拟分析表明在上部结构荷载作用下筏板及桩体周围的位移量较大，离桩筏基础越远位移量越小，筏板的沉降呈盆状；桩距径比越大筏板沉降量越大，桩长越大筏板沉降量越小。由于桩体轴力的作用，筏板边缘桩体位置处的剪应力出现集中，且筏板负弯矩有极大值；筏板内弯矩随着上部结构荷载的增大而增大；桩距径比越大筏板内的弯矩越小，桩长越大筏板内的弯矩越大。%A numerical analysis model was established to study structure-foundation-flyash interaction. Response of raft was studied through different distance diameter ratio and pile length. Numerical simulation show that, displacements near raft and pile are large,and the settlement on raft has basin shape. The raft settlement increases with distance diameter ratio,while decreases with pile length. Owing to axial load acted on raft,mises stress concentrates on raft edge,and hogging moment has a maximal value. Moment on raft is closely related to the upstructure load. Moment on raft decreases with distance diameter ratio,while increases with pile length.