引大济湟工程TBM挤压大变形卡机计算分析与综合防控  

Analysis and comprehensive prevention-control for TBM jamming induced by squeezing deformation of surrounding rock around water diversion tunnel from Datong river into Huangshui river

作　　者：黄兴[1] 刘泉声 彭星新[1] 雷广峰 魏莱[1] HUANG Xingl LIU Quan-sheng PENG Xing-xinl LEI Guang-feng WEI Lai(State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071 China Key Laboratory of Geotechnical and Structural Engineering Safety of Hubei Province, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]武汉大学土木建筑工程学院岩土与结构工程安全湖北省重点实验室,湖北武汉430072

出　　处：《岩土力学》2017年第10期2962-2972,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.41602326);国家重点基础研究发展计划(973)资助项目(No.2014CB046904;No.2015CB058102)~~

摘　　要：针对青海省引大通河济湟水河(引大济湟)工程频繁遭遇挤压大变形和卡机灾害难题,基于挤压大变形本构模型和全断面隧道掘进机(TBM)卡机事故预测分析理论,提出了挤压大变形和卡机计算方法,进行了引大济湟工程TBM掘进围岩挤压大变形与卡机计算,结果表明:(1)TBM穿越F5断层区段时,当扩挖间隙为10 cm时,开挖卸荷后护盾所受摩阻力将达到推进系统提供的最大推力,易发生卡机事故;(2)挤压变形、围岩-护盾接触面积和护盾所受摩阻力随停机时间不断增大,停机1 d内增大的速率越来越大,停机后7 d起,围岩流变速率和护盾所受摩阻力增加速率均减缓,直到停机后13 d时,围岩-护盾相互作用达到平衡,护盾所受摩阻力趋于稳定。同时为了防止和控制卡机事故,对该工程后续施工提出了最佳扩挖间隙和许可停机时间等卡机综合防控的3个对策:即扩挖间隙至少要增大到15 cm,此时停机初始时刻不发生卡机,许可停机时间为2 d;扩挖间隙增大到18 cm时,许可停机时间为4 d;扩挖间隙增大到20 cm时,就选取的围岩条件下,停机7 d内TBM基本不发生卡机,7 d后也很容易克服卡机。提出的卡机防控措施对引大济湟工程TBM安全高效掘进具有一定的指导意义,并得到工程实际控制对策的验证。This study aims to solve the problem of the frequent TBM jamming caused by the large squeezing deformation of surrounding rock around the water diversion tunnel from Datong river into Huangshui river in Qinghai province. Based on the constitutive model of squeezing deformation and the shield jamming prediction theory, we developed a procedure to calculate squeezing deformation and shield jamming. The main conclusions are drawn as follows. When TBM advances through F5 fault section and the overcut gap is 10 cm, the friction on the shield reaches the maximum thrust supplied by the propulsion system, which may result in shield jamming. As the growth of the downtime, the squeezing deformation, the contact area between surrounding rock and shield, and the friction on the shield increase with the stoppage. The growth rate is getting greater on the first day. However, the creep rate of surrounding rock and its friction growth rate decrease from the seventh day. The interaction between surrounding rock and shield reaches a balance until the thirteenth day, and the friction on the shield becomes stable. The above results are consistent with observed data in the field. Furthermore, to prevent and control shield jamming, we provide the following advice for optimal overcut and permissible downtime for further tunnelling. The over gap should be larger than 15 cm, under which the shield will not be jammed at the tunnelling unloading instant, and the permissive downtime is 2 days. When the overcut increases to 18 cm, the allowable stoppage is 4 days. While the over gap reaches 20 cm, shield jamming will not happen on the whole within 7 days under the surrounding rock condition, which also can be easily overcome. These control measures are substantially significant in the safety and efficiency of TBM tunnelling, which are also verified by the engineering practice.

关 键 词：引大济湟 隧道掘进机(TBM) 挤压大变形 卡机 防控 

分 类 号：TV52[水利工程—水利水电工程]