刚性桩复合地基桩土应力比计算方法研究

Study of the Stress Ratio between Column and Soil in the Composite Ground Improved by the Rigid Columns

采用规范设计方法计算刚性桩复合地基的承载力和沉降量不能得到准确解。刚性桩复合地基桩土体系工作的核心是桩土荷载分配。以桩土变形协调为边界条件(此条件也是优化设计追求的目标),采用桩土分算和弹性理论建立了桩-土-褥垫层的计算模型,并推出了求解桩土应力比的迭代方程。在成都某项目中通过方程求得了桩土应力比,并将计算结果与实测数据进行了比对,结果表明模型与实际吻合较好。

The accurate bearing capacity and the settlement of the composite ground usually could not be obtained by using the current design code method.The critical aspect of the composite ground formed by the rigid column is the load distribution in the column-soil system.Based on the compatible deformation between the column and the soil,which is the objective of the design optimization,the analytical model of the column-soil-load transfer layer is established by using the elastic theory and the separate stress analysis between the column and the soil.The iteration process is used in order to obtain the stress ratio between the column and the soil.The analytical results are close to the measured results.