【作者】 任涛；

【导师】 凌道盛；

【作者基本信息】 浙江大学 ， 岩土工程， 2012， 硕士

【摘要】 由于具有良好的水平承载性能,斜桩以及有斜桩的群桩基础被广泛应用于桥梁、码头、大型输电以及斜坡上建筑等工程中。目前,针对斜桩承载性能的研究主要集中在试验方面,理论上的分析研究相对较少。本文根据斜桩桩侧土体受力特征,假设桩侧浅层土体达到极限破坏时在桩侧被动破坏区形成一个三维楔形体。基于极限平衡理论导出了不同倾角斜桩桩侧极限土抗力,考虑了斜桩倾角、桩土界面摩擦作用等因素对桩侧极限土抗力的影响,数值对比分析了斜桩和直桩桩侧极限土抗力的差异。基于三维楔形体模型,提出了斜桩初始地基反力模量的确定方法,修正了砂土地基中直桩Reese的p-y曲线,提出了砂土斜桩地基中p-y曲线确定方法。在此基础上,基于虚功原理,导出了梁单元、非线性地基土弹簧单元的有限元列式,给出了有限元迭代求解方法。编制了相应分析程序,通过简单算例验证了非线性土弹簧单元的合理性和有效性。最后,采用本文程序对一离心机模型试验进行了模拟分析,结果表明计算结果和试验结果吻合得很好。更多还原

【Abstract】 With a good level of horizontal bearing capacity, battered piles and pile groups contains batter piles are widely used in bridges, piers, large-scale transmission lines, buildings on the slope and other projects. Meanwhile. The research about bearing capacity of battered piles are mainly in the laboratory test, the theoretical analysis are rarely reported.According to the mechanical characteristics of soil which is in the side of battered piles, the three-dimensional wedge model is proposed when the shallow soil of pile side is in the limit state in the pile side of the passive region in this paper. Based on the theory of limit equilibrium and considering many factors on the ultimate soil resistance of pile side, the ultimate soil resistance of battered pile at different angle in shallow strata is deduced, subsequently, numerical analysis shows the difference between the ultimate soil resistance of battered piles and the ultimate soil resistance of plumb pile. Based on the three-dimensional wedge model, the method for determining initial subgrade modulus of battered piles is proposed and the p-y curve for plumb pile in sands proposed by Reese is modified in this paper, then p-y curve method for analyzing the bearing characteristic of horizontal loaded single battered pile in sands is obtained. On the basis of above-mentioned work, using the virtual work principle, the finite element formulations of beam element and nonlinear foundation soil-spring elements are deduced, then the finite element iterative method is given. The corresponding analytical procedures is programmed, then the effectiveness and rationality of the nonlinear soil spring elements is verified through a simple example. At last, numerical analysis of centrifuge model test shows that the results match with the model experiment results.更多还原