桩筏基础固结沉降实用计算方法

Practical Method for Piled Raft Consolidation Settlement Calculation

摘要:

针对饱和深厚黏土中的摩擦型桩筏基础，提出求解基础体系固结沉降的简化分析方法.采用桩土筏非线性共同作用模型和交替方向隐式差分算法求解二维平面应变区域内任意时刻不同位置的超孔隙水压力，计算桩端以下土层的平均固结度和基础体系的固结沉降.与有限元精确解的对比分析表明，提出的计算模型与简化假定基本合理.将该方法用于分析2个饱和黏土地基中的桩筏基础固结沉降，得到了与实测值比较接近的预测结果.

关键词:桩筏基础;固结;沉降计算;非线性;隐式差分算法

Abstract:

A practical method for calculating the consolidation settlement of frictional piled raft foundation in deep clay was presented. Nonlinear model considering pilesoilraft interaction and alternating direction implicit finite difference algorithm were adopted to solve excess pore water pressures at different positions in twodimensional plain strain domain, average consolidation degree of soil below pile tip and consolidation settlement of piled raft in any time. The results from comparison with the accurate solution of finite element method show that the proposed model and the simplified assumptions are basically reasonable. Finally the method was successfully applied to the consolidation settlement prediction of two pile raft cases in saturated clay.

Key words:piled raft; consolidation; settlement calculation; nonlinearity; implicit finite difference algorithm