近距双线盾构隧道开挖诱发地层变形演变规律及数值模拟.

The influence of the mutual disturbance of twin tunnels shield construction on the distribution characteristic and evolution rules of the stratum deformation are significant. On the basis of the case study of the twin parallel shield tunnels of subway, considering the critical distance and the interaction effects of twin shield construction. Adopting numerical simulation method to analyze the evolution rules of stratum deformation caused by twin shield construction and combining with the actual measurement date, and the prediction model of stratum deformation caused by twin shield tunnels construction was put forward consider the critical distance. The results show that the stratum vertical deformation curve is developed into an asymmetrically "W" shape from the "V" shape when the twin tunnels excavated successively. The range of settlement trough is increased from 6D to lOD, and the more obvious is the "W" shape settlement curve characteristic with the stratum depth increasing. The stratum horizontal deformation curve is the asymmetric distribution, and the soil deformation is greatly influenced by construction disturbance in the middle of twin tunnels. The shape of surface settlement curve successively transformed from deep "V" shape, shallow "V" shape, "U" shape, shallow "W" shape, deep "W" shape and then to two independent "V" shape with the critical distance of twin tunnels, and using Lcr = 2CKH can be considered as the criterion of critical distance for the twin parallel shield tunnels. The prediction model proposed in this paper can better reflect the influence rules of critical distance state and mutual disturbance on stratum deformation caused by twin tunnels shield construction. The research provides reference for similar subway tunnel shield construction deformation prediction and refinement control. [ABSTRACT FROM AUTHOR]