【摘要】 对于紧邻地铁枢纽的深基坑工程,其开挖方式对基坑变形特性和施工安全控制有着显著影响。以上海某紧邻地铁隧道的深基坑工程为背景,其设计方案将该基坑工程划分为大、小基坑分别施工,重点研究大、小基坑的开挖方式对于围护结构及地铁隧道变形的影响。针对"先挖大基坑,后挖小基坑"的开挖方案,采用离心模型试验,研究开挖过程中地下连续墙和隧道结构的变形特性。试验结果表明,"先挖大基坑,后挖小基坑"的开挖方案可以有效地控制基坑变形,所得结论对于类似的紧邻地铁隧道深基坑工程设计与施工具有参考价值。更多还原

【Abstract】 For deep foundation pit nearby metro stations,the excavation scheme has significant influence on the deformation of foundation pit and construction safety.A deep foundation pit adjacent to metro tunnels in Shanghai is investigated as the research background.The foundation pit is divided into a big part and a small part in the design scheme.A feasible excavation scheme is proposed to excavate the big part firstly.This investigation is mainly performed to analyze the impacts of excavation sequences on the deformations of the retaining walls and tunnels.Centrifugal model tests are introduced to study the deformation behaviors of the retaining walls and tunnel structures.The analysis results show that excavating big part of the pit firstly is more reasonable to control the deformation of foundation pits.The conclusions have some instructions for designs and constructions of similar engineering.更多还原