静力压桩临界深度和最小厚度探讨

根据土塑性力学基本原理 ,用空穴球形扩张理论推得了沉桩时沉桩阻力沿深度变化的理论计算方法 ,对有软弱下卧层的桩基持力层、桩尖离下卧层顶面应留的最小厚度 ,无软弱下卧层的桩基持力层、桩尖进入持力层的临界深度 ,以及最小厚度或临界深度在不同土层或土层组合时的差别等三个问题进行了讨论。计算结果与工程实测结果对比 ,二者比较接近。还就现行规范中桩基进入持力层深度或离软弱下卧层距离大小的规定进行了讨论。

Study on the critical depth and minimal thickness of static piling

Based on the theory of soil plastic mechanics,a method to calculate the variation of soil resistance with depth during pile installation has been presented,three problems about minimal thickness from pile toe to the top of soft substratum,critical depth of pile toe penetrating into the bearing stratum and variation of minimal thickness or critical depth for different soil stratum have been discussed.The calculated results are in good agreement with the site measurements.Minimal thickness and critical depth determined by current pile code are compared with the presented results.