Study On Effcting Factors Of Displacement And Control Measures Of Shield Tunnel Segment

The paper takes the shield tunnel construction of one interval in the Chengdu subway for engineering background. Aiming at the staggered platform caused by segment displacement in the current shield construction. Through the analysis of the data in the field statistics and the numerical simulation to study segment dislocation and force condition, as the same time, to analyze influencing factors to put forward relevant control measures. Main research results of the paper as follows:(1) According to the on-site monitoring data to analyze overall distribution law of segment dislocation along tunnel longitudinal and change law of segment dislocation when the distance between segment and tunnel face increases during shield driven. Result shows that segment dislocation increases at first then decreases, on the whole, and tends stable at last. As well, segment dislocation tends to stable with the distance between segment and tunnel face in the influence of buoyancy after segment out of shield tail.(2) According to the on-site monitoring data of segment dislocation and shield construction and after the processing the largely discrete monitoring data with mathematical method to analyze influence of each construction parameter to segment dislocation. Put forward the construction range of each construction parameter basis for analysis results.(3) Through the numerical simulation to analyze the influence of soil thickness, cylinder thrust force, grouting pressure and bolt pertightening to the segment dislocation. Result shows that as soil thickness and grouting pressure increasing, the segment dislocation is also increasing and the distribution pattern of grouting pressure has great influences on the distribution location of segment dislocation. While as the cylinder thrust force and bolt pertightening increasing, the segment dislocation is decreasing.(4) According to the research results of on-site monitoring data and numerical simulation to analyze influencing factors of segment dislocation and put forward control measures of segment dislocation with practical construction situation.