湿陷性黄土隧道重载条件下对隧道结构下部的影响分析  

Analysis of Influence of Collapsible Loess Tunnel on the Lower Part of the Tunnel Structure under Heavy Load Conditions

作　　者：王虎[1] WANG Hu(China Railway 18th Bureau Group No.1 Engineering Co.,Ltd.,Baoding 072750,Hebei,China)

机构地区：[1]中铁十八局集团第一工程有限公司,河北保定072750

出　　处：《路基工程》2023年第6期80-85,共6页Subgrade Engineering

摘　　要：为了解铁路隧道运营期间受重载列车动载的影响下,基底围岩和支护结构的动力响应规律,以蒙华铁路王家湾隧道为依托,基于其特有的湿陷性黄土地层,通过现场围岩取样,并对岩样进行室内试验确定模型地层参数,通过激励力函数模拟列车动载;采用有限元软件,建立隧道列车-轨道数值模型,研究在不同行车速度下基底围岩的加速度响应、竖向应力响应、竖向变形和支护结构的加速度响应、应力响应。结果发现:行车速度的改变对基底加速度、竖向应力和竖向变形的响应规律不会产生大的改变,但加速度峰值对于行车速度的敏感性更高;随着基底围岩深度的增加,两种加速度以及动应力的峰值都明显降低。在振动荷载下,基底围岩的响应结果显示:0~3 m为振动强影响区,3~5 m为振动弱影响区。支护结构下部结构应力要远大于拱部应力,故在实际工程中建议增强重载铁路隧道下部结构。边墙部位所受的影响时间相对更长,若边墙处存在缺陷问题,在围岩压力以及列车重载动载循环下会发生破坏。In order to understand at railway tunnel in operation the dynamic response laws of the basement surrounding rock and the supporting structure under impact of heavy train dynamic,Wangjiawan Tunnel of Menghua Railway was taken as an example to carry out the study in such manner that,based on its unique collapsible loess stratum,the surrounding rock was sampled on site and tested in laboratory to determine the formation parameters of model,then the dynamic load of train was simulated by the function of exciting force,by use of finite element software,the tunnel train-track numerical model was established to make the research under different running speed the acceleration response,vertical stress response,vertical deformation of the basement surrounding rock and the acceleration response,stress response of the supporting structure.The rusult shows out that:the change of running speed will not cause great changes on the response laws of base acceleration,vertical stress and vertical deformation,however the peak acceleration is of higher sensitivity against the running speed;as the depth of basement surrounding rock increases,the peak values of two kinds of acceleration and the dynamic stress decrease obviously;under vibrating load,the results of the basement surrounding rock responses show a strong vibration effect region at 0−3 m and a weak vibration effect region at 3−5 m;the stress in the substructure of support is far greater than that in the arch,thus in the actual project,it is recommended to strengthen the substructure of heavy-haul railway tunnel.The side wall has been affected for a relatively longer time and,if there exists any defect,it will be destroyed under the surrounding rock pressure and the cyclic heavy dynamic load of train.

关 键 词：重载铁路 湿陷性黄土 激励力函数 动力响应 运营安全 

分 类 号：U451.3[建筑科学—桥梁与隧道工程]