真空堆载联合预压复合地基径向固结理论研究

Study on Radial Consolidation Theory of Vacuum-surcharge Combined Preloading Composite Foundation

针对真空堆载联合预压复合地基径向固结问题,建立空间轴对称变形计算模型,采用位移法求出土体的变形和体积应变,给出真空堆载联合预压复合地基径向固结解。通过退化分析和与已有解的比较研究,验证了此解的正确性和合理性。基于此解,通过算例计算,绘制出各参数对复合地基固结速率影响的曲线图。研究表明:桩径比n和扰动区影响因子s越小,复合地基固结速率越快;扰动区土体径向渗透系数越大,复合地基固结速率越快;桩土弹性模量比越大,复合地基固结速率越快;长细比越小,复合地基固结速率越快;径向时间因子越大,复合地基径向固结度越高。

Aiming at the problem of the radial consolidation of the vacuum-surcharge preloading composite foundation,a spatial axisy mmetric deformation calculation model was established.The deformation and volume strain of the unit body were obtained by the displacement method.The radial consolidation solution of vacuum surcharge preloading composite foundation was given.The correctness and rationality of this solution were verified by degradation analysis and comparison with existing solutions.Based on this solution,a graph of the influence of various parameters on consolidation rate of the composite foundation was drawn through calculation of several examples.The results show that the smaller the pile diameter ratio and the influence factor of disturbance area,s,the faster the consolidation rate of composite foundation;the larger the radial permeability coefficient of soil in disturbed area,the faster the consolidation rate of composite foundation;the larger the pile-soil elastic modulus ratio,the faster the consolidation rate of composite foundation;the smaller the slenderness ratio,the faster the consolidation rate of the composite foundation;the larger the radial time factor,the higher the radial consolidation degree of the composite foundation.