Influence Analysis on a Subway Shield Tunnel Crossing below a High Speed Railway

摘要

This paper chooses the section between the stations of Majiapu Donglu and Yongdingmenwai Dajie on Beijing subway line 14 as the object. Numerical simulation is adopted to analyze the function of grouting reinforcement in control of deformation of the earth surface while a shield tunnel crosses below the Beijing-Tianjin intercity high speed railway. A 3D numerical model is made to simulate the construction process of a shield tunnel crossing below a high speed railway with a top speed of 350km/h, where the differential settlement between the two rails is required less than 5mm. The calculation result indicates that grouting reinforcement to the stratum of a certain extension of the crossing section can effectively control the settlement of the existing railway caused by shield tunneling so as to ensure safety operation of the railway. And the behindsegment grouting parameters and soil compartment pressure in the shield structure gained in the study can be instructional for further design and construction of tunnels.