端承桩水平振动响应能量变分分析方法  

Variation solution for horizontal dynamic response of an end-bearing pile

作　　者：张慧[1] 李小娟[1] 屈青山[1] 

机构地区：[1]黄淮学院建筑工程学院,河南驻马店463000

出　　处：《铁道科学与工程学报》2017年第4期730-738,共9页Journal of Railway Science and Engineering

摘　　要：考虑竖向荷载对桩基水平承载力的影响,采用能量法对地基土中端承桩的水平振动问题进行理论研究。根据分析动力学建立在水平动荷载作用下桩土系统的拉格朗日方程,通过复变函数和广义变分原理分别建立桩基和土体控制方程,采用分离变量法推导出土体位移表达式,结合桩土耦合振动条件和迭代程序得到桩基位移、内力和桩顶水平动力复阻抗解析表达式。通过算例分析,研究竖向荷载对桩顶动力复阻抗的影响以及桩周土剪切模量和桩长对桩身位移分布规律的影响。研究结果表明:动力复阻抗随竖向荷载增大而逐渐降低,桩身水平位移和转角随桩周土剪切模量增加而注浆降低;桩长达到有效桩长时,桩土系统有效耦合振动长度不发生变化。The lateral dynamic response of an axial loaded pile in soil was investigated by an energy approach in this paper. Lagrange Equations of the pile-soil system bearing horizontal dynamic load were established based on the analytic dynamics. Complex variable function and extended variational principle were utilized to deduce the governing equations of the pile and soil. Expressions of soil displacements were obtained according to method of separation of variables. Lateral displacements, internal forces and complex impedances of the pile under horizontal vibration were derived based on the continuous conditions between the pile and soil and iterative program. Numerical examples were carried out to investigate the influence of axial load on horizontal dynamic response and shear modulus of soil and pile length on the distribution law of pile displacement. The results show that： the dynamic complex impedances decrease with the increase of axial loads; horizontal displacement and rotation angle decrease, when shear modulus of the surrounding soil decreases; the length of the coupled vibration of the pile-soil system shows little variation, when the pile length reaches the critical value.

关 键 词：竖向荷载 水平振动 复阻抗 变分原理 

分 类 号：TU473.1[建筑科学—结构工程]