柔性基础下不排水桩复合地基固结分析

考虑柔性基础下不排水桩复合地基中桩–土非等应变特性，推导出变荷载下不排水桩复合地基桩间土平均超静孔隙水压力的控制微分方程和求解条件。通过函数变换，基于变荷载下天然地基一维固结理论建立了相应的固结解析解，包括复合地基和桩间土中的平均超静孔隙水压力解答和复合地基整体平均固结度解答。利用有限元模拟方法验证了固结解析解的合理性，并与现有的固结度解析解进行了比较。结果表明，固结度解析解与数值模拟的结果较为吻合，计算精度高于现有的固结计算模型。采用基于等应变假设的固结计算模型分析路堤下不排水桩复合地基的固结速率，计算结果偏大。

Consolidation analysis of composite ground with undrained columns under flexible foundation

Considering the non-equal strain between the column and the surrounding soil within the composite ground with undrained columns under flexible foundation, the governing differential equation of the average excess pore water pressure in the soil around columns and the corresponding solution conditions under time-dependent load were derived. Based on the one-dimensional consolidation theory of natural soil foundation under time-dependent load, the corresponding analytical solutions were developed by the function transformation method. The average excess pore water pressures in the composite ground and the surrounding soil, and the overall average consolidation degree of the composite ground were included in the analytical solutions. The proposed solution was compared with the existing analytical solutions in the literatures and the numerical result obtained from the finite element method (FEM) to validate its accuracy. The results show that the proposed solution and FEM results have a good match, and the accuracy of proposed solution is higher than those of the existing consolidation models. The consolidation rate of the composite ground with undrained columns under embankment is overestimated by the analytical consolidation solutions based on the equal vertical strain assumption.