长水泥土桩-短碎石桩复合地基固结解析解

基于轴对称固结模型并采用等竖向应变假设,给出瞬时荷载下长水泥土桩-短碎石桩复合地基的固结方程,推导出单面排水条件下复合地基的固结解析解,包括桩间土和碎石桩的平均超静孔隙水压力解和复合地基的整体平均固结度解.将固结度解析解与有限元数值解进行对比,证明了解析解的合理性.最后,利用固结度解对影响复合地基固结速率的主要因素进行...

Analytical solution for consolidation of composite ground with long cement-soil columns and short stone columns

Combining the axisymmetric consolidation model and the equal vertical strain assumption, differential equations governing the consolidation of a composite ground with long cement-soil columns and short stone columns subjected to an instant load were presented. The corresponding analytical solutions were derived under single-drainage condition, including the solution of average excess pore water pressures in the interior of a stone column and subsoil around a cement-soil column, and the solution of overall average degree of consolidation of the composite ground. Then, the proposed analytical consolidation solution was verified via the comparison with the numerical solution by the finite element method. Finally, some main influencing factors were analyzed to investigate the consolidation behavior of the composite ground. The results show that the penetration ratio of the stone columns (ratio of stone column length to soil thickness) is a crucial factor affecting the consolidation rate of the composite ground, and the higher the penetration ratio, the faster the consolidation of the composite ground. It increases gradually with the increase of the permeability coefficient and area replacement ratio of the stone columns, as well as the area replacement ratio and constrained modulus of the cement-soil columns. For the situation of higher values of penetration ratios, the variation of the well resistance and the area replacement ratio of the stone columns has obvious influence on the consolidation rate. The change in the constrained modulus of the stone columns has a limited effect on the consolidation rate of the composite ground.