刚性基础下碎石桩复合地基临塑荷载的确定

为探讨碎石桩复合地基的承载力,从碎石桩的荷载传递和破坏性状出发,建立碎石桩复合地基的计算模型。基于半空间轴对称弹性理论及基本假定,考虑散体材料桩在荷载传递过程中的径向膨胀变形,根据桩土变形协调及桩土界面上径向应力平衡条件,得到桩土应力比的表达式。应用莫尔-库仑破坏准则,给出了碎石桩复合地基临塑荷载和临界荷载的计算公式。最后,与碎石桩复合地基极限承载力经典方法的计算结果进行对比,结果表明,计算所得的临界荷载十分接近。

THE CRITICAL EDGE LOAD OF COMPOSITE GROUND REINFORCED BY STONE COLUMNS UNDER RIGID FOUNDATION

In order to determine the capacity of composite foundation,the computational model for composite foundation reinforced by stone columns is founded according to load transfer characteristics and failure pattern.The expression of pile-soil stress ratio considering lateral bulging deformation is obtained according to spatial axisymmetric elastic theory and basic assumptions,which includes deformation compatibility and the equilibrium of radial stress on the interface between stone column and soil.The calculation method of the critical edge load and the critical load of composite foundations reinforced by stone columns is provided by the application of Mohr-Coulomb's failure criterion to soil between stone columns.The critical load is approximate to the results of the classical methods for ultimate capacity of composite foundation.