复合地层盾构引起地表沉降塌陷研究综述

REVIEW ON GROUND SUBSIDENCE CAUSED BY SHIELD TUNNELING IN COMPOSITE STRATUM

在复合地层盾构开挖掘进中,常常会遇到密闭舱内土砂粘结、涌水和涌沙等若干问题,从而导致地表沉降、地面塌陷等事故。国内外学者对复合地层地表沉降、支护力与土体位移关系以及地面塌陷机理进行了大量研究,将相关研究成果依据研究方法分类,从理论分析、模型试验和数值模拟对研究现状进行总结。建议对复合地层各覆土层沉降规律、支护力不足时的破坏形状,影响极限支护力因素的粘聚力、内摩擦角及地下水渗流进行深入研究,通过数值模拟分析各覆土层沉降曲线,利用模型试验研究复合地层地面塌陷机理,总结各覆土层沉降规律和地面塌陷模式,从而提出更加适用于复合地层的地表沉降计算公式和地面塌陷破坏模型。

Sand bonding,water gushing, and sand gushing in the enclosed cabin are often encountered during the excavation of composite stratum shield tunneling,resulting in surface subsidence and ground collapse. Scholars at home and abroad have studied on the surface settlement of composite stratum,the relationship between supporting force and soil displacement,and the mechanism of ground collapse. The relevant research results are classified according to research methods,and the research status is summarized from theoretical analysis,model test, and numerical simulation. It is recommended to conduct an in-depth study on the settlement law of each overlying layer in the composite stratum, the failure shape with the insufficient supporting force,the cohesion and the internal friction angle, and the groundwater seepage of the factors that affect the limit supporting force. Additionally,the settlement curve of each overlying layer is analyzed through numerical simulation. Model tests are used to study the ground collapse mechanism of composite stratum,and the settlement laws and ground collapse modes of each overburden layer are summarized,so as to propose a more suitable ground settlement calculation formula and ground collapse failure model for composite stratum.