单桩轴向荷载沉降曲线广义剪切位移解析算法

Analytical Solution for Axial Loading-settlement Curve of Piles Using Extensive Shear Displacement Method

用线性弹性和塑性线性强化模型模拟桩周土的剪应力与剪应变非线性关系,将弹性阶段的剪切位移法推广到塑性阶段,得到了广义剪切位移理论,建立了桩土间耦合力学模型;利用此理论,分别对桩周土处于弹性、半塑性和全塑性3个不同阶段进行分析,推导出了不同边界条件下桩的荷载 沉降曲线的解析表达式以及统一解析式,对实际桩基进行了计算。研究结果表明:该方法能模拟工程中的复杂情况,从而能够解决复杂桩周边界条件下的桩基承载力与沉降问题,计算结果与实测结果最大误差为7.8%,平均误差为 6%;由于考虑了桩土之间的连续性,利用该单桩承载力 沉降解析表达式能够求解桩土共同作用地基桩的承载力与沉降位移。

Nonlinear relationship between shear stress and shear strain was simulated by a linear elastic-plastic linear intensified model, in which the surrounding soil was divided into three different status in whole loading periods, i.e., linear-elasticity, partial-plasticity and complete-plasticity. Based on detailed analysis, the analytical expressions for different boundary conditions as well as an unified expression for axial load-settlement of pile were derived. The results show that the proposed method is very simple and effective, it can deal with the pile settlement under complex surrounding conditions. The method is of high precision, with the maximum error being within 7.8%, the average error being 6% only. Since the continuity between pile and soil is also considered in the theoretical derivation, the obtained analytical formula can be widely used to solve practical engineering problems.