水平荷载单桩计算的非线性地基反力法研究  

Solutions for laterally loaded single pile by nonlinear subgrade reaction method

作　　者：张磊[1] 龚晓南[1] 俞建霖[1] 

机构地区：[1]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058

出　　处：《岩土工程学报》2011年第2期309-314,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50708093)

摘　　要：为提高桩身变形较大时水平荷载单桩设计计算水平,基于地基反力法提出了考虑极限土反力和地基反力系数一般形式的桩身的变形和内力的计算方法。对于土为塑性和弹性状态对应的桩段分别求得到了桩身响应的解析解和半解析解,并用Fortran语言编制了计算程序。计算结果分析表明:桩的位移和弯矩均随荷载的增加而大幅度增大;桩顶的约束条件对位移和弯矩沿桩身的分布影响很大;当桩长超过临界值时,继续增加桩长对桩的响应影响极小,且临界桩长基本不受荷载和桩顶约束条件的影响;桩的最大位移和最大弯矩随桩周土的物理力学性质的改善而明显减小;最大位移随桩的抗弯刚度的增加而减小,而最大弯矩受抗弯刚度的影响很小;计算值与现场试验的实测值吻合较好,本文解是可靠的。In order to improve the design and calculation of laterally loaded single pile when the pile deflection is comparatively great,the calculation method of the deflection and internal force of the pile is proposed based on the sugrade reaction method,in which the limiting resistance of soil and the common expression of the coefficient of subgrade reaction are considered.Analytical and semi-analytical solutions for the pile shaft in the plastic and elastic zones of soil are presented,respectively,and then the relevant computer program is developed using the Fortran language.The computed results indicate that the displacement and the bending moment increase significantly when the loads increase.The pile head condition plays an important role in the distributions of the displacement and the bending moment along the pile shaft.When the pile length exceeds the critical value,which is almost not influenced by loads and the pile head condition,pile responses nearly do not change when the pile length increases.The maximum lateral displacement and bending moment can be effectively decreased by improving the mechanical properties of the soil surrounding the pile.The maximum lateral displacement decreases when the pile stiffness increases,while the maximum bending moment is hardly influenced by the pile stiffness.The computed values are in good agreement with the measured values from a field experiment,which means that the suggested solutions are reliable.

关 键 词：桩土相互作用 水平荷载 地基反力法 极限反力 半解析解 

分 类 号：TU473[建筑科学—结构工程]