INFLUENCE OF EXCAVATION ON EXIST METRO SHIELD TUNNEL AND CONTROL MEASURES

The metro shield tunnel has strict deformation control requirements. As the development of subway network, the adjacent excavation has become an important hidden threat to subway tunnel safety. First, the paper introduces the commonly used constitutive models and their parameter obtaining method in numerical simulation of a deep excavation project. Then, the change law of the tunnel deformation and stress due to deep excavation in the side or above of a metro tunnel are studied, and tunnel deformation control measures for the excavation with the underlying tunnel or tunnel in flank are developed. Meanwhile the advanced methods of tunnel deformation and force monitoring are introduced. At the end, for the cracks and water-leakage caused by the oversize deformation of the shield tunnel segment, the relevant tunnel reinforcement methods and their effect are presented. The direction for further research is put forward.