城市地铁穿越岩溶地段盾构掘进技术  

Shield tunneling technology for urban subway crossing karst section

作　　者：吴发展 刘道炎 Wu Fazhan;Liu Daoyan(The Erchu Co.,Ltd.,of China Railway Tunnel Group,Sanhe 065201,China)

机构地区：[1]中铁隧道集团二处有限公司,三河065201

出　　处：《青海交通科技》2022年第4期152-158,共7页Qinghai Transportation Science and Technology

摘　　要：岩溶专项勘察报告揭示岩溶发育区溶洞形状复杂且不规则,为确保盾构机通过岩溶区的施工安全及盾构隧道以后的安全运营,研究岩溶发育区轨道交通工程隧道建造技术具有较重要的理论价值和工程意义。岩溶探测方法采用孔间层析成像(CT)和高密度电阻率法,勘察钻探揭示本场地溶洞情况;建立隧道三维有限元模型模拟盾构地铁掘进施工过程,研究不同埋深处溶洞对隧道稳定性的影响;施工前对溶洞做注浆加固预处理,盾构掘进中重点监测排泥量,同时加强同步注浆工作。岩溶注浆加固效果显著,盾构隧道施工中未出现塌陷、坍塌等情况。研究结果表明:(1)随着埋深的增加,隧道在竖直方向的沉降位移逐渐变大,施工初期应该密切监测隧道的变形量。(2)对岩溶区实施合理的加固处理措施,满足盾构掘进安全及隧道结构稳定。(3)盾构机选型充分研究分析地质、水文和周围环境情况,考虑掘进地层有黏土和风化岩,选用土压平衡盾构机进行施工。(4)盾构顺利通过岩溶区,盾构姿态控制良好,根据监测数据显示,地表沉降控制到位,地表最大沉降量满足规范及设计要求。(5)根据隧道三维有限元模型数值分析结果,结合盾构施工实际控制值比较,隧道拱顶沉降变化受埋深影响较大,预加固后的岩溶对隧道本身基本无影响。The karst special investigation report reveals that the karst caves in the karst development area are complex and irregular in shape.In order to ensure the construction safety of the shield machine passing through the karst area and the safe operation of the shield tunnel in the future,it is of great theoretical value and engineering significance to study the tunnel construction technology of rail transit projects in the karst development area.The inter hole tomography(CT)and high-density resistivity method are used for Karst Detection,and the survey drilling reveals the karst cave situation of the site;Establish a three-dimensional finite elementmodel of the tunnel to simulate the tunneling process of shieldmetro,and study the influence of karst caves at different buried depths on the stability of the tunnel;Before construction,the karst cave shall be pre treated with grouting reinforcement.During shield tunneling,the mud discharge shall bemonitored and the synchronous grouting shall be strengthened.The reinforcement effect of karst grouting is remarkable,and there is no collapse and collapse during shield tunnel construction.The following conclusions are drawn:(1)with the increase of buried depth,the settlement displacement of the tunnel in the vertical direction gradually increases,and the deformation of the tunnel should be closely monitored at the beginning of construction.(2)Reasonable reinforcemen tmeasures shall be taken in the karst area tomeet the safety of shield tunneling and the stability of tunnel structure.(3)The selection of shield machine shall fully study and analyze the geology,hydrology and surrounding environment.Considering that there are clay and weathered rock in the tunneling stratum,the earth pressure balance shield machine shall be selected for construction.(4)The shield passed through the karst area smoothly,and the attitude of the shield was well controlled.According to the monitoring data,the surface settlement was controlled in place,and themaximum surface settlementmet the specific

关 键 词：轨道交通 地铁 岩溶 隧道 盾构 

分 类 号：U231.3[交通运输工程—道路与铁道工程] U455.43[建筑科学—桥梁与隧道工程]