Regularity and Prediction of Segment Floating of Shallow Buried Large Diameter Shield Tunnel in Soft Soil Area:A Case Study on Shanghai Airport Contact Line
In order to explore segment uplifting pattern and influencing factors of large-diameter shield tunnel in soft soil area,based on the measured data of project of shallow buried large-diameter tunnel of Shanghai airport contact line,the influence of shield attitude change on segment uplifting was analyzed.The correlation between segment uplifting and tunnelling status was revealed.And a nonlinear prediction method for segment uplifting considering multiple factors was proposed.The process of segment uplifting can be di-vided into four stages:initial deviation and deformation before exiting the shield tail,rapid uplifting(5 rings from the shield tail),slow uplifting(5～15 rings from the shield tail)and settlement.Segment uplifting is greatly affected by shield attitude,segment attitude and overcutting.The uplifting of the segment is positively correlated with the average thrust,shield elevation and average propulsion speed,while negatively correlated with the gap difference between lower and upper shield tails.The nonlinear fitting method can pre-dict tunnel uplifting well taking multiple factors into consideration.The research can provide reference for prediction and control of up-lifting of shallow large-diameter shield tunnel.
万方数据
维普
