超大直径盾构盾壳被砂浆固结包裹原因分析及处理措施  

Cause Analysis and Countermeasures for Super-Large-Diameter Shield Shell Consolidated and Wrapped by Mortar

作　　者：徐明远 邹小春 张晓 杨伟鸿 XU Mingyuan;ZOU Xiaochun;ZHANG Xiao;YANG Weihong(CCCC Tunnel Engineering Co.,Ltd.,Beijing 100102,China;Shenzhen University,Shenzhen 518060,Guangdong,China)

机构地区：[1]中交隧道工程局有限公司,北京100102 [2]深圳大学,广东深圳518060

出　　处：《隧道建设（中英文）》2023年第12期2133-2138,共6页Tunnel Construction

摘　　要：为解决超大直径盾构被砂浆固结包裹引起的地面隆起、管片上浮、管片错台等问题,对可能导致砂浆固结包裹的原因如停机时间过长、注浆量过大、水泥质量浓度过高和处于液化砂层等进行分析,并针对固结原因提出采用打桩机夹住拉森钢板桩振动盾体、疏松盾体外的砂浆结块及土体的方法清除盾体外包裹的固结砂浆。研究结果表明:1)砂浆包裹与地层土渗透系数大、同步注浆水泥质量浓度过高有一定的关系;2)盾构经常性停机会促使砂浆固结包裹;3)通过振动钢板桩的方式可以有效去除盾壳外包裹的砂浆,并可通过调整同步注浆施工工艺以避免再次出现此情况。Critical issues in shield tunneling,such as prolonged shield shutdowns,excessive grouting volume,high cement content,and the challenges posed by liquefied sandy layers,contribute to the consolidation and wrapping of the shield shell by the mortar,leading to ground uplift,segment floating,and dislocation.A novel mortar removal technology that uses a pile driver to clamp a Larsen steel sheet is proposed.This method vibrates the shield body and effectively loosens mortar caking and soil encrusting the shell.Key findings include the following:(1)The consolidation and wrapping of the shield shell by mortar are partly attributable to the high ground permeability coefficient and cement concentration in the synchronous grout.(2)Frequent shield shutdowns exacerbate mortar consolidation and wrapping.(3)The proposed measures are effective in removing mortar from the shell,and the occurrence of such phenomena can be minimized by enhancing synchronous grouting techniques.

关 键 词：超大直径盾构 砂浆固结包裹 钢板桩 

分 类 号：U45[建筑科学—桥梁与隧道工程]