桩承加筋垫层复合地基桩土应力比分析

Analysis of Pile-soil Stress Ratio of Pile-supported and Geogird-reinforced Composite Foundation

对带桩帽的桩承式复合地基水平加筋垫层进行受力变形分析,得出加筋体的挠曲变形量及筋材拉应力。在此基础上,视复合地基中竖向桩体和桩间土体为线弹性体,由静力平衡及变形协调条件,同时考虑筋材拉应力的作用,得到水平加筋垫层上下桩土应力比的计算方法。该方法能反映桩土间的差异沉降量、水平向加筋体抗力作用、桩间距、桩帽直径等因素对桩土应力比的影响。最后,采用该方法对某一现场试验结果进行分析,理论值与实测值吻合较好。水平加筋垫层的存在使复合地基桩土应力比增大,地基承载力提高,用文中方法计算桩承加筋垫层复合地基桩土应力比是可行的。

The load and deformation of the pile-capped horizontal reinforced cushion of the pile-supported and geogrid-reinforced composite foundation were discussed to obtain the deformation and the tension stress of the reinforced material.Treating the pile and the soil as linear elastic object,and considering the static equilibrium and the compatibility of deformation as well as the influence of the reinforced material,the calculation method of the pile-soil stress ratios in different depths of the reinforced material was deducted.This method takes the following influence factors into account： differential settlement between pile and soil,horizontal reinforced cushion,pile distance,diameter of the pile cap and so on.Finally,to validate the proposed method,a case study was illustrated,which shows that the calculated value is close to the observed value.The pile-soil stress ratio and the bearing capacity of the composite foundation will be higher after setting up the horizontal reinforced mattress.This method is feasible for calculating the pile-soil stress ratio of the pile-supported and geogird-reinforced composite foundation.