The Discussion of Influential Factors on Tunnel Upheaval Deformation Induced by Deep Pit Excavations Above Metro Tunnels

Projects of deep excavation became more common nowadays in modern city development for underground spaces exploitation, and some of them were crossing over the existing metro tunnels. Safety of metros would be threatened in case that excavation processes were not controlled considerately and unexpected deformation of tunnels was induced accordingly. The upheaval behaviors of the tunnel were actually caused by the above soil unloading and stress redistribution within the soil body. Due to the complexity of problems, some of factors, such as excavation depth, excavation manner and tunnel shape were mainly discussed in the paper. Factors study was made based on monitoring data and three-dimensional Finite Element Method. It is helpful to better understand upheaval behavior of tunnels induced by upper excavation so as to avoid excessive tunnel deformation in similar engineering cases.