深圳地铁浅埋暗挖隧道地层变形分析

Analysis of Ground Deformation for Shallow Tunnel in Shenzhen City

地铁隧道施工扰动地层,必然造成相应的地层变形,并且在不同条件下变形量表现出较大的差异.通过对深圳地铁Ⅰ期工程3A标国老区间隧道砂质地层深部位移的现场实测和分析,得出了深圳富水软弱含砂地层中浅埋暗挖法施工地层运动的基本规律.该类地层具有变形量大的显著特点,并且地表沉陷具有突发性,地层损失率高达9.2％,远大于普通地层.结合地质及工程条件对地层大变形机理及其主要影响因素进行了分析.在此基础上提出了控制地层大变形的技术措施,在Ⅰ期工程的后期施工中得到充分利用且取得较好的指导施工效果.

Because constructing metro tunnel at shallow depth damages stratum, stratum stress is freed and corresponding deformation is generated. For deformation there is biggish difference due to difference of stratum conditions. By in-suit monitor and theory analysis about deep stratum displacement of Guomao-Laojie overlapping tunnel in metro Phase I of Shenzhen, basic movement characterstics of stratum above tunnel caused by constructing in weak watery stratum were obtain. The big surface settlements and outburst is notable characterstics of Shenzhen stratum, and stratum deformation is outburst. The loss ratio of overlying stratum arrives at 9. 2% , it is much larger than that of common stratum. Furthermore, stratum behavior and main influence factors were also analysised in allusion to geologic and engineering conditions. Subsequently, corresponding technologic measures of how to control large deformation in stratum were proposed and fully applied to the construction late in phase I project. Good effects were achieved in guiding tunnel construction.