陡坡地段桩板结构路基动荷载作用响应分析

Dynamic Loading Response Analysis of Pile-plank Structure in Steep Slope Subgrade

为了研究陡坡路基桩板结构动荷载作用的响应规律,利用ABAQUS有限元分析软件进行数值模拟,对杭黄客专某桥隧间陡坡短路基道砟与填料的动应力传递、加速度、动应力时程对比及板结构应力分布等进行研究。数值模拟结果表明:道砟层表面的最大加速度幅值约为1.8 m/s^2,较填料的最大幅值(约1.3 m/s^2)高出约27.7%;填料处的最大动应力(37 kPa)远小于道砟上的最大动应力(74kPa),约为道砟层最大应力的一半;板上最大正应力约为70 kPa;最大负向应力约为181.5 kPa。研究表明:道砟层对于动加速度的衰减作用和动应力的消散作用较为明显;板上应力最大位置位于桩顶处,最大正应力的位置为左排与中排桩桩顶处,最大负向应力的位置为右排桩桩顶处。

In order to study the dynamic loading response laws of pile-plank structure in steep slope subgrade,the ABAQUS finite element analysis software is used to study the dynamic stress transfer between ballast and filling,the acceleration,the time-histories comparison of dynamic stress and the stress distribution of pileplank structure of steep slope short subgrade between the bridge and tunnel of Hangzhou-Huangshan Highspeed Railway.The numerical simulation results show,the maximum acceleration amplitude of ballast surface is about 1.8 m/s^2,which is about 27.7%higher than that of packing(about 1.3 m/s^2);the maximum dynamic stress on the filling(37 kPa)is far less than that on the ballast(74 kPa),and is about half of the maximum stress of ballast;the maximum normal stress on the plank is about 70 kPa,while the maximum negative stress is about 181.5 kPa.The research shows,the attenuation effect of ballast on dynamic acceleration and the dissipation effect on dynamic stress are obvious;the maximum stress on the plank is at the top of the pile,the position of maximum normal stress is at the top of left row and middle row of piles,and the position of the maximum negative stress is at the top of the right row of piles.