深埋高地应力重载铁路隧道基底动力响应分析

Dynamic Response Analysis of the Deep-buried and Heavy-haul Railway Tunnel Base with High Ground Stress

研究目的:在重载列车长期振动作用下,隧道基底结构极易出现开裂、破损等现象,深埋隧道基底结构这类病害更为显著,甚至可能导致基底整体的隆起破坏,严重影响列车运营安全.为揭示重载列车振动作用下深埋铁路隧道基底的动力响应特征,通过数值模拟的方法建立重载深埋铁路隧道动力分析模型,探明在该环境下隧道基底结构的受力及病害特征,进一步结合工程实际提出病害处理措施及效果.研究结论:(1)深埋隧道基底结构承受远大于浅埋隧道主应力量值,在重载列车循环荷载作用下更易出现开裂、破损、隆起等病害;(2)在重载列车荷载作用下,隧道基底结构的动位移和动应力随着铺底厚度和仰拱厚度的增加而逐渐减小;(3)相较于铺底厚度,仰拱厚度的增加更有利于重载铁路隧道支护结构在循环荷载作用下竖向位移和应力的控制,更不容易出现疲劳开裂等问题;(4)本研究成果可应用于高地应力重载铁路隧道的设计及病害处理领域.

Research purposes:Under the long-term vibration of heavy-duty trains,the tunnel base structure is prone to cracking and damage.Such diseases are more serious in the base structure of deep-buried tunnels,and may even lead to the uplift and damage of the whole base,which seriously affects the safety of train operation.In order to reveal the dynamic response characteritics of the deep-buried railway tunnel base under the vibration of the heavy-duty train,a dynamic analysis model of the heavy-duty deep-buried railway tunnel was established by means of numerical simulation,and the stress and disease characteristics of the tunnel base structure in this environment were verified.Further combined with the actual project,the disease treatment measures and effects were proposed.Research conclusions:(1)The base structure of the deep-buried tunnel bears much more than the prineipal stress value of the shallow-buried tunnel,and it is more likely to suffer from cracks,damage,uplift and other diseases under the cyclic load of the heavy-duty train.(2)Under the action of the heavy-duty train load,the dynamic displacement and dynamic stress of the tunnel base structure gradually decrease with the increase of the thickness of the bottom and the thickness of the invert.(3)Compared with the thickness of the bottom,the increase of the thickness of the invert is more conducive to the control of vertical displacement and stress of the support structure of heavy-haul railway tunnels under the action of cyclic loads,which are less prone to problems such as fatigue cracking.(4)The research results can be applied to the field of the design and disease treatment in deep-buried and heavy-haul railway tunnel.