摘要
膨胀土地基中,土的膨胀率和刚度沿深度变化明显:较深位置的膨胀土应力水平较高,一方面遇水的膨胀率较小,另一方面土的刚度较大。该文基于桩-土相互作用机理,利用荷载传递法推导了考虑膨胀土沿深度膨胀率减小、刚度增加的单桩理论求解方程,并得到了级数形式的解析解。理论解与现场和模型试验数据符合较好,尤其是轴力沿桩身发展的模式。之后该文在膨胀土层的平均膨胀率和平均模量不变的前提下,分析了不同膨胀位移分布模式和刚度分布模式对桩受力和变形的影响,发现若按传统的土沿深度膨胀率和刚度为常值计算,将过高地估计单桩的轴力和位移。利用此解析解还讨论了膨胀土中桩的临界压重。
In expansive soil stratum, soil swelling rate and stiffness varies obviously with depth. In deeper sites, the stress level of expansive soils is higher, which leads to greater stiffness and a smaller expansion rate. Based on the mechanism of pile-soil interaction, single pile analytical equations considering stiffness increase and expansion decrease along the depth of soil are derived by the load transfer method, and the solution is expressed in a Taylor series. Calculation results conform to the field and model test data, especially the mode of pile deformation, verifying the reliability of the solution. Under conditions of constant average expansion rate and average stiffness, the effects of displacement distribution mode and stiffness distribution mode to pile-soil load transfer are studied. Results show that the traditional assumption, of a constant swelling rate and stiffness distribution along the depth of soil, will significantly overestimate the pile axial force and displacement. The analytical solutions are used to discuss the critical pile head load also.
出处
《工程力学》
EI
CSCD
北大核心
2016年第12期86-93,共8页
Engineering Mechanics
基金
国家重点基础研究发展计划项目(2014CB047004)
关键词
膨胀土
单桩
荷载传递
位移
刚度
解析解
桩-土相互作用
expansive soil
single pile
load transfer
displacement
stiffness
analytical solution
pile-soil interaction
