基于现场实测的流砂偏压隧道围岩大变形特征分析  

Analysis of Large Deformation Characteristics of Surrounding Rock in Drift Sand Bias Pressure Tunnel Based on Field Measurements

作　　者：潘红伟 李军 王永刚 郑军 尉敏 满超群 白希铜 龙葳 PAN Hongwei;LI Jun;WANG Yonggang;ZHENG Jun;WEI Min;MAN Chaoqun;BAI Xitong;LONG Wei(China Railway Beijing Engineering Bureau Group First Engineering Co.,Ltd,Xi'an 710000,China;China Railway Beijing Engineering Bureau Group Co.,Ltd,Beijing 100000,China;Chang'an university,Xi'an 710064,China)

机构地区：[1]中铁北京工程局集团第一工程有限公司,西安710000 [2]中铁北京工程局集团有限公司,北京100000 [3]长安大学,西安710064

出　　处：《铁路工程技术与经济》2023年第6期20-24,34,共6页Railway Engineering Technology and Economy

摘　　要：本文以某样本隧道为背景,通过对典型断面开挖后的现场监测和三维数值模拟,探讨了流砂偏压段隧道围岩和支护体系的变形及受力特征。结果表明:受左上方处于潜塑状态的流砂层影响,隧道开挖后,隧道左侧支护结构所受围岩压力为形变压力;左侧应力释放导致竖向沉降呈现出明显的“左大右小”的非对称分布特点;竖向临时钢支撑对限制围岩变形无明显作用;采用“三角式”钢桁架封闭断面,并辅以小导管径向注浆,可有效控制隧道围岩变形;流砂层在开挖后形成了贯通的塑性区域,左侧锚杆没有很好发挥锚固效果,建议在后续施工中使用中空注浆锚索代替。研究成果可为类似上覆流砂段隧道工程的设计、施工及应急预案制定提供一定的参考。This article takes a sample tunnel as the background,and explores the deformation and stress characteristics of the surrounding rock and support system of the tunnel in the section of drift sand and eccentric pressure through on-site monitoring and three-dimensional numerical simulation after excavation of a typical section.The results show that due to the influence of the flow sand layer in the upper left plastic state,the surrounding rock pressure on the left support structure of the tunnel after excavation is deformation pressure;The release of stress on the left side leads to a significant asymmetric distribution of vertical settlement characterized by"large left and small right";Vertical temporary steel support has no significant effect on limiting the deformation of surrounding rock;The use of a"triangular"steel truss to close the section and the use of small conduits for radial grouting can effectively control the deformation of the tunnel surrounding rock;After excavation,the flowing sand layer formed a continuous plastic zone,and the left anchor rod did not perform well in anchoring.It is recommended to use hollow grouting anchor cables instead in subsequent construction.The research results can provide certain reference for the design,construction,and emergency plan formulation of tunnel projects similar to the overlying quicksand section.

关 键 词：铁路隧道 受力特征 现场试验 流砂地层 数值计算 偏压隧道 

分 类 号：U456.3[建筑科学—桥梁与隧道工程]