Surface Subsidence Monitoring and Study on Deformation Laws in Shield Curve Tunnel Construction

Deformation laws of the Ф10.0 meter EPB shield curve construction are studied.The radius of curvatureR=350 m andR=354 m in one metro tunnel in Beijing Subway are selected as the monitoring objects.The geometrical leveling is taken as the monitoring method.It could be known through the analysis of subsidence deformation data that the main settlement deformation undergoes 5 stages:pre-settlement,settlement after shield tail prolapsed,grouting uplift,stable settlement,and postsettlement.The envelope graph of ultimate settlement presents an approximate partial normal distribution;the symmetric axis is partial to the inner side of the curve.