摘要
Abstract
The frequent occurrence of ground collapse disasters induced by shield tunneling in metro tunnels has become a prominent issue.In Shanghai,ground collapse caused by shield tunneling is primarily attributed to ground loss,which is closely related to construction control parameters such as advance speed,muck discharge volume,and support pressure.Minor cases may lead to ground settlement,while severe cases can trigger face instability,progressing from localized failure to overall collapse of the overlying soil.Two typical scenarios leading to ground loss are"blowout"at the screw conveyor outlet and"breakthrough"of slurry into the tail void.Lithology,geotechnical physical-mechanical parameters,and hydrogeological conditions constitute the dominant geological factors controlling metro tunnel stability.In Shanghai,silty strata under high water pressure pose higher construction risks compared to soft clay layers.Ground collapse is more likely to occur in scenarios involving shallow burial,large diameter,small curvature radius,or steep gradient tunneling.High-risk zones for ground collapse include shield launching/arrival sections,cross-passage areas,as well as locations adjacent to deep excavations or beneath rivers,pipelines,and existing lines,where stress conditions are complex.关键词
盾构隧道/地面塌陷/成因要素/地层损失/地质环境Key words
shield tunnel/ground collapse/factors of causes/ground loss/geological environment
