Analytical solutions for laterally loaded step-tapered piles by state space method
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摘要: 为研究阶梯型变截面桩的水平承载特性,基于Timoshenko梁理论,建立了综合考虑桩基尺寸效应、剪切变形和桩基材料非线性效应的四弹簧模型及其状态方程,获得了非线性桩土相互作用下任意长细比的桩截面内力与变形解析解。通过与已有文献中现场试验结果对比分析,验证该方法的适用性和有效性,并讨论了变径位置、桩径比和弹性模量比对桩基受荷特性的影响。研究结果表明:①桩基水平承载力对三者的敏感性为:桩径比 > 变径位置 > 弹性模量比;②综合考虑桩承载能力和经济性,建议变径位置、桩径比和弹性模量比取0.6。Abstract: To analyze the response of laterally loaded step-tapered piles, a four-spring model is proposed based on the Timoshenko beam theory considering the effects of pile diameter, shear deformation and nonlinear pile material behavior. The analytical solutions for the internal forces and deformations with arbitrary slenderness ratio can be derived by the state space method considering the nonlinear pile–soil interaction. The solutions are validated through the available field test results in the literatures. Furthermore, the influences of pile parameters, such as the variation position of the diameter, diameter ratio and Young's modulus ratio, on the pile loading responses are proposed. The results show that: (1) The sensitivity of these parameters follows the descending order: pile diameter ratio > variation position of pile diameter > Young's modulus ratio. (2) After trade-off between the pile lateral bearing capacity and the cost, it is suggested that the optimal variation position of the diameter, the pile diameter ratio and Young's modulus ratio should be set as 0.6.
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Keywords:
- step-tapered pile /
- lateral load /
- pile-soil interaction /
- Timoshenko beam /
- four-spring model /
- state space method
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表 1 桩顶与桩端的约束边界条件
Table 1 Boundary conditions of pile head and end
桩顶/端 约束形式 边界条件 桩顶 自由 固支 桩端 自由 铰接 固支 -
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