某浅埋偏压铁路隧道变形综合治理及监测研究  

Research on Deformation Control and Monitoring of Shallow Buried Unsymmetrical Railway Tunnel

作　　者：崔俊杰 王凯 雷星 杜文山 CUI Junjie;WANG Kai;LEI Xing;DU Wenshan(China Railway Engineering Design and Consulting Group Co.,Ltd.,Beijing 100055,China)

机构地区：[1]中铁工程设计咨询集团有限公司,北京100055

出　　处：《铁道标准设计》2022年第9期116-122,共7页Railway Standard Design

基　　金：中铁工程设计咨询集团有限公司科技开发计划重点课题(研2020-6)。

摘　　要：广西某铁路浅埋偏压隧道在施工和运营期间出现变形,体现为衬砌开裂、地表裂缝与边坡滑移等病害,影响行车安全。为明确变形原因并提出合理治理措施,同时探明综合加固措施对坡体和隧道的加固效果及其稳定性状态,通过地质勘察、现场监测试验与理论分析等技术手段,对该典型浅埋偏压山区铁路隧道进行变形特征、变形原因、综合治理措施及其现场监测试验等方面研究。结果表明:(1)加固前隧道内水沟电缆槽侧壁、仰拱、拱顶等出现裂缝,地表相继出现纵向开裂和弧形裂缝,地表变形较大;(2)隧道边坡变形主要由于隧道通过丘陵斜坡中下部,呈浅埋偏压,洞身所在地层为全风化层,坡脚开挖造成应力释放,稳定性差,持续降雨强度大,地表水下渗较严重;(3)提出卸载反压、注浆增强、锚索桩相结合的综合加固处理方案。加固后,地表横向位移呈幅值小于4.7 mm的小幅波动状态,锚索桩深部横向位移最大挠跨比为1.45‰,有效抵抗地层下滑力;隧道径向、竖向相对位移稳定在较小值,有效控制了隧道和边坡变形发展,增加其稳定性。During construction and operation,deformation occurs in a shallow-buried and biased tunnel on a railway in Guangxi,and affects driving safety due to lining cracking,surface cracks,slope slippage and other damages.In order to clarify the cause of deformation and put forward reasonable treatment measures,and,at the same time,to explore reinforcement effect of comprehensive reinforcement measures on the slope and tunnel and their stability,deformation characteristics,causes and treatment measures of the typical shallow buried and biased mountain railway tunnel are studied based on geological survey,on-site monitoring and theoretical analysis.The results show:(1)Before reinforcement,cracks appear at some locations on the sidewalls,surface and secondary lining of the water trench and cable trench in the tunnel,and longitudinal cracks and arc-shaped cracks emerge successively on the surface;(2)The deformation of the tunnel slope is due to tunnel passing through the middle and lower part of the hilly slope,which is shallow buried and biased.The layer where the tunnel body is located is a fully weathered layer of sandstone,which is weak,poor in stability,heavy in rainfall,and serious in surface water seepage;(3)A comprehensive reinforcement treatment plan combining unloading back pressure,grouting reinforcement and anchor-cable piles is proposed.After reinforcement,the lateral displacement of the ground surface shows a small fluctuation with an amplitude less than 4.7 mm.And the maximum torsion-span ratio in the deep part of the anchor-cable pile is 1.45‰,which effectively resists the sliding force of the ground.Also,The relative displacement of the tunnel in the radial and vertical directions is stable at a small value.This measure effectively controls the deformation and development of the tunnel and the slope and increases their stability.

关 键 词：铁路隧道 浅埋偏压隧道 变形特征 锚索桩 变形机理 综合整治措施 现场监测 

分 类 号：U459.1[建筑科学—桥梁与隧道工程] U457.2[交通运输工程—道路与铁道工程]