摘要
我国西部、西南部地区在建及建成的高速铁路隧道常发生仰拱隆起病害,严重威胁着隧道施工进度及运营安全。依托兴山东隧道典型的水平层状碳质页岩地层,开展仰拱基底隆起机理研究,对仰拱基底以下的围岩进行模型简化,应用构件试验定性分析、数值模拟定量计算的方法,揭示了不同层厚、层间黏聚力以及材料强度对层状岩体破坏模式的影响,分析导致水平层状围岩隧道底鼓的原因,并提出相应的底鼓控制处置技术。研究结果表明:(1)层厚的减小降低了层状复合岩体抵抗变形和破坏的能力,主要表现为弹性阶段的缩短和变形速率的加快;层间黏结强度的降低破坏了层状复合岩体的整体性,导致层状岩体加速进入单一岩层受力阶段,但对极限承载力劣化效应不明显;(2)岩体本身材料强度降低极大地降低了层状复合岩层的承载能力,使得破坏过程显著加快,影响程度和范围进一步加深,结合数值模拟结果进一步证明了岩体本身强度在层状岩体的变形和破坏当中占据主导位置;(3)列车振动的疲劳损伤、地下水聚集的弱化作用以及围岩的长期力学性能均将影响隧道仰拱的稳定性,变形控制效果排序为:加深仰拱>基底注浆>仰拱锚杆。
In the western and southwestern regions of China,under-construction and completed highspeed railway tunnels often suffer from elevated floor heave,which seriously threatens the construction progress and operational safety of the tunnels.This paper relies on the typical horizontally laminated carbonaceous shale stratum of the Xingshandong Tunnel to carry out a research on the mechanism of elevation of the base of the back arch.The model of the surrounding rock below the base of the elevated arch is simplified by applying the method of qualitative analysis by component testing and quantitative calculation by numerical simulation.The effects of different layer thicknesses,interlayer cohesion and material strength on the damage pattern of laminated rock masses are revealed,the causes of bottom bulging in horizontally laminated rock enclosures are analysed and corresponding bottom bulge control and disposal techniques are proposed.The results indicate:(1)The reduction in layer thickness reduces the ability of the laminated composite rock mass to resist deformation and damage,mainly manifested in the shortening of the elastic phase and the acceleration of the deformation rate;the reduction in the bond strength between layers destroys the integrity of the laminated composite rock mass,leading to the acceleration of the laminated rock mass into the single rock layer stress phase,but the effect on the deterioration of ultimate bearing capacity is not obvious;the reduction in the strength of the rock mass itself greatly reduces the load-bearing capacity of the laminated composite rock formation,causing the damage process to accelerate significantly and further deepening the extent and scope of the impact,which,combined with the numerical simulation results,further proves that the strength of the rock mass itself dominates the deformation and damage of the laminated rock mass.(3)The fatigue damage of train vibration,the weakening effect of groundwater aggregation and the long-term mechanical properties of the surrounding rock will all affect the stability of the elevation arch of the tunnel,and the order of deformation control effect is:deepening invert>base grouting>invert arch bolt.
作者
周俊超
ZHOU Junchao(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)
出处
《铁道标准设计》
北大核心
2024年第6期145-152,共8页
Railway Standard Design
基金
国家自然科学基金高铁联合基金项目(U2034205)。
关键词
高速铁路
铁路隧道
水平层状围岩
仰拱底鼓
构件试验
数值模拟
变形机理
high-speed railway
railway tunnels
horizontally laminated surround rock
floor heave
component test
numerical simulation
deformation mechanism
作者简介
周俊超(1985-),高级工程师,2012年毕业于西南交通大学桥梁与隧道工程专业,工学硕士,主要从事隧道研究、设计工作,E-mail:168328122@qq.com。
