Monitoring of surrounding rock deformation in tunnel excavation and back analysis of initial stress field

Early-warning issue of tunnel construction is important.During the construction process of Zhuzangdong Tunnel in Gucheng-Zhuxi Highway in Hubei Province,in view of the regression model of exponential function based on the in-situ monitoring data,the back analysis on stress field of rock mass in the tunnel project area was conducted by the method of displacement back analysis.Tunnel construction was simulated in accordance with the results of the above back analysis to determine the distribution characteristics of the stress field in the project area.The results of analysis coincides with the results of stress test of surrounding tunnels,which can provide the reference for the safe construction of the project,the layout of monitoring cross-section,stability evaluation of surrounding rock,and determination of secondary lining time.