摘要
为有效探明盾构隧道坍塌机制,防止重大事故发生,提出了隧道结构坍塌破坏的定量分析方法。针对佛山2018年2月7日盾构工程施工坍塌事故,利用该方法确定了隧道结构坍塌范围,利用数值模拟手段揭示了地层掏空及隧道坍塌形成机制,通过与现场情况对比,验证了分析方法的有效性。结果表明:在高压富水地层,盾尾透水会掏空或松动隧道围岩,降低衬砌结构稳定性;隧道在结构破坏前先发生材料的局部破坏,最终当隧道两侧失去地层约束,承受上部全覆土压力时,发生变形、开裂、刚度降低,最终导致隧道结构坍塌。最后,针对富水地层等不良地质条件区域,从勘察设计、结构设计、施工技术、防堵水技术、避难逃生等方面提出了措施建议,为盾构隧道安全施工提供参考。
To effectively clarify the collapse mechanism of shield tunnel and prevent major accidents occurrence,a quantitative analysis method for the collapse of the tunnel structure is proposed.For the collapse accident of the shield tunnel in Foshan on February 7,2018,the method is used to find the scope of the tunnel structure collapse,and numerical simulation is carried out to discover the mechanisms of ground cavity formation and the tunnel collapse.The effectiveness of the analysis method was verified by comparison with the on-site situation.The results show that:In the high-pressure water-rich stratum,the leakage of shield tail will hollow out or loosen the surrounding ground of tunnel,reduce the stability of the tunnel lining,before the structure of the tunnel is destroyed,local material damage occurs first.Eventually,when the two sides of the tunnel are not constrained by the ground and bear the full earth pressure on the upper part,deformation,cracking,and stiffness reduction will occur,which will eventually cause the tunnel structure to collapse.Therefore,for water-rich strata or areas with poor geological conditions,this paper proposes suggestions from the survey and design,structural design,construction technology,waterproof technology,refuge and escape,and etc,It is expected to provide a reference for the safe construction of shield tunnel.
作者
农兴中
王剑宏
杨华
钟小春
何敬源
Nong Xingzhong;Wang Jianhong;Yang Hua;Zhong Xiaochun;He Jingyuan(Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou 510010,P.R.China;School of Qilu Transportation,Shandong University,Ji’nan 250002,P.R.China;College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2023年第S01期486-493,共8页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(52178390,51678217)
山东省自然科学基金(ZR2021ME165,ZR2020KE031)
关键词
盾构隧道
坍塌事故
数值模拟
地层掏空
结构破坏
shield tunnel
collapse accident
numerical simulation
stratum hollowed out
structural failure
