桩端下有软弱下卧层的群桩沉降分析

Analysis on Settlement of Pile-group With Soft Underlying Stratum

群桩沉降由桩身压缩和桩端沉降组成。本文采用桩身线弹性的假定计算单桩桩身压缩,用单桩的桩身压缩近似代替群桩桩身压缩,并用承台下的平均附加应力乘以桩端荷载传递系数后作为桩端的附加应力,推出了桩端下有软弱下卧层的群桩沉降计算方法,同时与其他计算方法和工程实测值进行了比较。

The settlement of pile-group consists of the compression deformation of pile shaft and the settlement of pile tip. In this paper, the compressive deformation of single pile shaft is calculated by adopting hypothesis of linear-elasticity, and the compressive deformation of pile-group shaft is approximate to the compressive deformation of single pile shaft. Moreover, the additional stress of pile tip is obtained by multiplying the average stress under pile cap or raft and the coefficient of transfer load. All these researches deduce the means of calculation of pile-group settlement with soft underlying straturr, In the end, the present method is compared with another method and practical project test results.