摘要
深圳地铁双模盾构在开挖岩质地层时,发生了多起卡机事故。为研究双模盾构卡机原因,并提出相应的预防处置措施,开展现场调研,统计了卡机位置的地质特征、盾构掘进参数和刀具磨损情况。结果表明:(1)双模盾构卡机与掘进模式及断面埋深有关,卡机主要发生在采用土压模式掘进的硬岩地层中,卡机断面均位于中等和大埋深位置;(2)卡机发生前,掘进参数出现异常变化,总顶推力显著提升,刀盘扭矩随之降低,盾构掘进速率缓慢下降,在卡机前短时间内剧烈减小直至为0;(3)边滚刀偏磨引起的扩挖间隙减小是造成卡机的主要原因,边滚刀在阻力矩作用下停止转动,其承受的滚动摩擦转变为滑动摩擦,刀具磨损速率上升产生偏磨,开挖直径随之减小;(4)垫高边滚刀能增大扩挖尺寸,对卡机进行预防,当卡机发生后,应依次采取减小盾壳摩阻力、提升顶推力和增大扩挖间隙的方法使盾构脱困。
Many jamming accidents happened in shield tunneling with dual-mode shield machine in Shenzhen metro line project.In order to analyze the cause and propose corresponding treatment methods,field investigations are conducted to identify the geological properties of jamming sections,collect operational parameters of the shield machine and find out the characteristics of worn cutters.The results indicate that:(1)the dual-mode shield jamming is related with the excavation mode and buried depth.Jamming accidents mainly occur in hard rock strata excavated under EPB mode.The jamming sections are all buried in medium or deep depth(2)The operational parameters tend to change abnormally before jamming happens.With significant increase of the total thrust force,the torque of cutter head gradually declines.The speed of the shield machine generally decreases at a low rate,and rapidly dropd to zero shortly before the accident occurs.(3)The crucial cause for dual-mode jamming is the reduction of the overcut clearance caused by the partial wear of edge disc-cutters.The edge disc-cutters gets stuck due to the excessive resistance torques.The friction born by edge disc-cutters changes from rolling friction to sliding friction,leading to the increase of wearing rate and resulting in partial wear of the cutters,and the excavation diameter decreases accordingly.(4)The edge disc-cutters should be padded to expand the overcut clearance to prevent jamming accidents.After jamming occurs,the friction of the shield shell should be reduced successively,total thrust force increased and overcut clearance expanded to release the shield machine.
作者
宋天田
马杲宇
姚超凡
王士民
康潇月
SONG Tiantian;MA Gaoyu;YAO Chaofan;WANG Shimin;KANG Xiaoyue(Shenzhen Metro Group Co.,Ltd.,Shenzhen 518026,China;Key Laboratory of Transportation Tunnel Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《铁道标准设计》
北大核心
2023年第6期131-139,共9页
Railway Standard Design
基金
住房和城乡建设部科学技术计划项目(2020-K-140)
国家自然科学基金重大项目(51991394)。
关键词
地铁
盾构隧道
岩质地层
双模盾构卡机
滚刀力学特性
扩挖间隙
metro
shield tunnel
rock strata
dual-mode shield jamming
mechanical properties of disc-cutters
overcut clearance
作者简介
宋天田(1978-),男,正高级工程师,2008年毕业于同济大学道路与铁道工程专业,工学博士,主要从事城市轨道交通工程研究工作,E-mail:stt5@163.com。
