列车轴载作用下轨道-横观各向同性地基动力响应  

Dynamic response of a track coupled with a transversely isotropic ground due to train axle loads

作　　者：李义成 冯世进[1,2] LI Yi-cheng;FENG Shi-jin(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土力学》2021年第5期1313-1324,共12页Rock and Soil Mechanics

基　　金：国家杰出青年科学基金项目(No.41725012)。

摘　　要：为研究列车荷载引起的环境振动问题,建立了轨道-多层横观各向同性(TI)地基耦合解析模型。与已有轨道-单一介质地基耦合模型相比,该模型考虑了地基中单相和两相TI介质层的交替分布,以模拟不同含水条件的TI岩土层。基于该模型,首先利用Fourier变换和势函数方法,求解TI介质控制方程;然后对精确刚度矩阵法进行推广,推导包含不同介质的多层地基解析解;最后结合轨道控制方程,通过逆变换得到耦合系统动力响应,并研究了地下水以及横观各向同性对轨道和地基动力响应的影响。结果表明:TI两相层中地下水的存在对轨道系统荷载放大系数的影响在荷载频率低于200 Hz时明显;地表振动沿垂直轨道方向的衰减速度随水平和垂直弹性模量比值的增大而加快;最大竖向应力幅值出现在地表1 m范围内;位移及应力的临界速度随水平和垂直弹性模量比值的增大而增大。To study the environmental vibrations induced by train loads,an analytical model for a track coupled with a layered transversely isotropic(TI)ground is developed.The model can consider the alternate distribution of TI elastic and poroelastic layers in the ground to describe soils and rocks under different moisture conditions compared with existing models comprising only one type of medium.Based on the analytical model,the governing equations of TI media are solved firstly using Fourier transform and a potential function method.Then the exact stiffness matrix method is adapted to derive solutions to the layered ground with different media.Finally,the dynamic response of the coupled system is obtained by using the governing equations of the track and inverse integral transformation.The influences of groundwater existence and transverse isotropy on the vibration of track and ground are investigated.It is found that the influence of the groundwater existence in the TI poroelastic layer on the track force amplification factor is significant at load frequency lower than 200 Hz.The ground surface vibration attenuates faster with the distance from the track center for a larger ratio of the horizontal elastic modulus to the vertical one.The maximum vertical stress magnitude occurs within 1 m from the ground surface.The critical speed of the displacement and stress increases with the increasing ratio of the horizontal elastic modulus to the vertical one.

关 键 词：轨道 横观各向同性 解析模型 交替分布 精确刚度矩阵 动力响应 

分 类 号：TU435[建筑科学—岩土工程]