【摘要】 深圳富水软弱地层地铁隧道开挖中出现的工作面失稳及由此引起的地表塌陷是地铁安全施工中极其重要的方面,对施工安全、进度都有较大影响,同时也对整个工程造成巨大的经济损失。通过对深圳地铁Ⅰ期工程土建施工中全线部分暗挖标段出现的工作面失稳、地表塌陷工程实践和现场监测结果分析,特别着重对连续2次出现地表塌陷的3A标暗挖隧道研究,从隧道上覆地层物理力学性质参数、地层变形监测分析及施工工艺原因3方面阐述了地表塌陷的原因。明确提出剪切破坏线和失水空洞区的概念,确定出引发地表塌陷的主导因素为施工工艺原因。建议针对该类地层条件,应做好超前地质预报,适当调整预加固参数,加强隧道结构和地表的动态变形监测,施工技术人员做到准确了解施工现场动态,及时调整施工工艺参数,以保证隧道的安全施工。分析结果对深圳地铁Ⅱ期工程施工及类似地层条件地下工程施工提供科学预测、预防地表塌陷的方法和技术措施,达到地铁隧道施工中经济效益与安全施工的统一。更多还原

【Abstract】 Face failure and ground subsidence caused by metro tunnel excavaton in weak watery stratum of Shenzhen play an important role in metro construction because they influence the safety and time of construction and also lead to large loss of the whole project.By face failure and ground subsidence investigation and in-suit monitoring analysis in some Lots of Shenzhen metro Phase Ⅰ line,especially of Lot 3A in which two large ground landlides have occurred in construction,the reasons of ground subsidence are expatiated respectively from three aspects,including the characters of the physical mechanical parameters of stratum above tunnel,the monitoring analysis of stratum deformation and contruction technics causation.The conceptions of shear failure line and desiccation hole zone have been put forward definitely,then the construction technics causation have been confirmed to be the predominant factor which cause the failure of ground.Finally,suggestions have been put forward to such stratum condition,such as putting geologic forecast in practice,adjusting pre-reinforcement parameter properly,strengthening dynamic deformation monitoring of tunnel structure and ground,knowing in-suit construction development,adjusting constructiontechnics to assure the construction safety and so on.Analysis result give some methods and technical measures of how to predict and prevent the failure of ground in scientific way to Shenzhen metro Phase Ⅱ and analogous underground engineering,and ensure the econmical benefit and construction safety of metro tunnel construction together.更多还原