变井阻条件下碎石桩复合地基固结解析解

Analytical Solution for Consolidation of Composite Ground with Stone Columns Considering the Time Dependent Well Resistance

针对实际工程中碎石桩复合地基固结的井阻问题,深入分析了碎石桩的井阻成因以及变井阻条件下的时间效应与空间效应.采用解析方法,建立了考虑井阻时间效应的复合地基固结方程.通过分析碎石桩渗透系数的变化规律构建了两种桩体渗透系数随时间变化的函数,并导出了特定变化模式下的碎石桩复合地基固结解析解.分析结果表明:井阻变化对于碎石桩复合地基固结速度影响显著,且该结果较现有的复合地基固结理论更接近工程实际;井阻因子初值越大,井阻时间效应的影响越严重;在相同条件下,增加桩体渗透性比提高桩体模量更有利于加速碎石桩复合地基固结.

Aiming at the well resistance during the consolidation process of composite ground with stone columns in practical engineering, the causes of well resistance and the time and space effect under variable well resistance condition were analyzed. The equations for the consolidation of composite ground considering time effect of well resistance were established by analytical method. Based on the variation of permeability coefficient of the stone column, two types of functions which describe the relationship between variation of permeability coefficient and time were built up and the general analytical solutions are derived under the specific variation modes for the consolidation problem of the composite foundation with stone columns. The results show that the variation of well resistance has a remarkable influence on the consolidation rate of composite ground with stone columns. Compared with the existing theories, the results of this paper are more reasonable. In addition, the larger the initial value of well resistance factor, the more significant the influence of the time effect of well resistance. In order to accelerate the consolidation of the composite ground, it is more efficient to improve the permeability rather than the modulus of stone columns under the same conditions.