富水硬岩地层盾构管片上浮机理及控制对策  

Floating Mechanism and Control Countermeasures of Shield Segment in Water-rich Hard Rock Formation

作　　者：艾国平 陈刚 刘维正[2] 戴晓亚 李英伟 AI Guoping;CHEN Gang;LIU Weizheng;DAI Xiaoya;LI Yingwei(CCCC Highway Engineering Co.,Ltd.,Beijing 100024,China;School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中交一公局集团有限公司,北京100024 [2]中南大学土木工程学院,长沙410075

出　　处：《现代交通技术》2021年第4期71-76,共6页Modern Transportation Technology

基　　金：湖南省住房和城乡建设厅科学技术计划项目(KY201943)。

摘　　要：管片上浮引发的错台、开裂是盾构隧道施工过程中的典型问题。针对长沙地铁6号线朝芙区间管片上浮严重的地段,分析了富水硬岩地层中管片上浮的机理,并采用数值模拟的方法探究了浆液凝固时间、浆液早期弹性模量及地下水位对管片上浮的影响,结合施工过程提出控制管片上浮的对策。研究结果表明:浆液的凝固时间对管片上浮影响最大,通过调整浆液的配比,让浆液在4~6 h内凝固可有效控制管片上浮;浆液的早期弹性模量对于管片上浮也有很大影响,可根据实际情况选择性质较好的浆液,其中双液浆可在30 s内速凝形成很高的弹性模量,可应用于上浮严重地段,抑制管片上浮;较低的地下水压力对抑制管片上浮较有利,在盾尾每10环施作止水环箍可有效形成止水隔离带,降低地下水的影响;控制同步注浆过程保证同步注浆的质量,其中注浆压力控制在设定范围内且不能超过设定值,将理论注浆量进行调整且增加管片上部注浆比例;控制盾构的掘进姿态从而减小管片受力不均引起的上浮,同时控制盾构掘进速度能够保证盾尾空隙被同步注浆浆液有效填充。Dislocation and cracking caused by the floating of segments are typical problems in the construction of shield tun-nels.Aiming at the severely floating segment of the Chaofu section of Changsha Metro Line 6,the mechanism of segment float-ing in the water-rich hard rock formation is analyzed,and numerical simulation methods are used to explore the effects of slurry solidification time,slurry elastic modulus and groundwater level on segment floating,and finally puts forward the countermeas-ures to control the floating of the slices combined with the construction process.The research results showed that:the solidifi-cation time of the slurry has the greatest impact on the floating of the segment,and by adjusting the ratio of the slurry,the slur-ry can be solidified within 4~6 hours to effectively control the floating of the segment;The early elastic modulus of the slurry also has a great impact on the floating of the tube pieces.The slurry with better properties can be selected according to the ac-tual situation.Among them,the double slurry can be quickly set within 30 s to form a very high elastic modulus,which can be applied to suppress the floating of the tube pieces in serious areas of floating;Lower groundwater pressure is more beneficial for suppressing the floating of the pipe segments.The installation of water-stop hoop every 10 rings at the tail of the shield can ef-fectively form a water-stop isolation zone to reduce the impact of groundwater;Control the synchronous grouting process to en-sure the quality of synchronous grouting.The grouting pressure is controlled within the set range and cannot exceed the set val-ue.The theoretical grouting volume is adjusted and the grouting ratio on the upper part of the segment is increased;The tunne-ling attitude of the shield is controlled to reduce the uplift caused by the uneven force of the segment,and the tunneling speed of the shield is controlled to ensure that the shield tail gap is effectively filled by the synchronous grouting slurry.

关 键 词：盾构隧道 管片上浮 数值模拟 影响因素 施工对策 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]