车辆载荷作用下桩后黏性土主动土压力分析  

Analysis of active earth pressure of cohesive soil behind piles under highway vehicle load

作　　者：李涛[1] 张添琦 吴雨停 王文博[1] LI Tao;ZHANG Tianqi;WU Yuting;WANG Wenbo(School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《辽宁工程技术大学学报（自然科学版）》2024年第1期20-29,共10页Journal of Liaoning Technical University (Natural Science)

基　　金：国家自然科学基金项目(42172319,51508556);中央高校基本科研业务费专项资金项目(2020YJSLJ14)。

摘　　要：针对现有设计规范进行桩后主动土压力计算时未考虑车辆载荷的动力效应对支护结构影响的问题,在平面滑裂面假定的基础上,结合拟动力学分析方法,考虑车辆动载荷作用下桩后土体受惯性力的影响,推导出车辆载荷作用下主动土压力的计算式,将主动土压力分为动土压力分量和静土压力分量。分析土体容重、桩-土外摩擦角对主动土压力的影响,以及水平振动加速度系数、内摩擦角、行车速度、车桩间距对动土压力的影响,对比分析不同黏聚力情况下的主动土压力分布规律。研究结果表明:桩后动土压力呈非线性分布;在车辆载荷作用下,一个振动周期内桩后主动土压力随滑动面倾角的增大和时间的持续先增大后减小;动土压力幅值随车桩间距的增大而减小,振动周期随车速的增大而增大。In view of the problem that the dynamic effect of vehicle load on the supporting structure is not taken into account when calculating the active soil pressure behind the pile in the existing design code,a formula for calculating the active soil pressure under the vehicle load is derived based on the assumption of plane sliding surface,combined with the pseudo-dynamic analysis method and considering the effect of the inertial force on the soil mass behind the pile under the vehicle dynamic load.The resultant force of active earth pressure is divided into a dynamic earth pressure component and a static earth pressure component.The influence of soil weight and external friction angle of pile-soil on the resultant force of active earth pressure is analyzed,and the influence of horizontal vibration acceleration coefficient,internal friction angle,driving speed and distance between piles on dynamic earth pressure is analyzed,and compared with the active earth pressure distribution law under different cohesive force.The research results show that the dynamic earth pressure behind piles is non-linear distribution;during a period of vibration,the resultant force of the active soil pressure behind the pile increases first and then decreases with the increase of the dip angle of the sliding surface and the duration of time;the dynamic pressure amplitude decreases with the increase of pile spacing,and the vibration period increases with the increase of vehicle speed.

关 键 词：车辆载荷 支护桩 黏性土 非线性分布 拟动力法 

分 类 号：TU432[建筑科学—岩土工程]