富水地层盾构下穿施工引起的管线变形分析

ANALYSIS OF PIPELINE DEFORMATION CAUSED BY SHIELD TUNNELING IN WATER-RICH STRATUM

隧道开挖导致的地层的沉降变形会通过外荷载的形式作用于邻近地下管线,使其受力性状发生变化,管线弯曲变形达到一定程度时,刚性管线可能出现裂缝甚至发生断裂。针对这一工程问题,文中以杭州地铁8号线浙江工商大学站-桥头堡站为工程背景,通过控制变量法,分析了盾构下穿埋深为1~6m的Q235钢管、铸铁管、C30混凝土管以及PVC管等多种工况下的管线引起的管线沉降变形规律,并根据分析结果对现有的通过地表沉降曲线最大斜率直接估算管线沉降变形情况及其安全性这一方法对各类管线的适用性进行了评价。然后,通过统计分析,提出了上述四种不同材质管线的管线最大沉降斜率与地表最大沉降斜率比值r随埋深h变化的线性拟合关系式,可以为通过观测地表最大沉降斜率估算地下管线最大沉降斜率提供参考。

The settlement deformation of the stratum caused by tunnel excavation will act on the adjacent underground pipeline in the form of external load,causing its stress behavior to change.When the pipeline bending deformation reaches a certain level,the rigid pipeline may crack or even break.Aiming at this engineering problem,this paper uses the Zhejiang Gongshang University Station-Qiaotoubao Station of Hangzhou Metro Line 8 as the engineering background.Through the controlled variable method,it analyzes the shield tunneling through Q235 steel pipes,cast iron pipes and C30 concrete with a buried depth of 1~6m.Pipeline settlement deformation law caused by pipelines under various working conditions such as pipes and PVC pipes,and based on the analysis results,directly estimate the pipeline settlement deformation and its safety through the maximum slope of the existing surface settlement curve.The applicability was evaluated.Then,through statistical analysis,the linear fitting relationship between the maximum subsidence slope of the pipelines of the four different material pipelines and the maximum surface subsidence slope ratio r with the buried depth h is proposed,which can be used to estimate the maximum subsidence slope of the underground pipeline by observing the maximum surface subsidence slope.The settlement slope provides a reference.