Research about Effect of Defects of Filled Layer in Inverted Arch on the Deep-Buried and Heavy-Haul Railway Tunnel Structures and Its Reinforcement Measures

The existence of the defects of filled layer in inverted arch leads to a more complicated stress state of the deep-buried and heavy-haul railway tunnel structures, which can easily cause the structural cracking and directly affect the safety of the tunnel structures. Based on deep-buried and heavy-haul railway Wuyanhe Tunnel in South Central Shanxi, the numerical simulation is used to analyze the effect of the defects of filled layer in inverted arch on the lining structure and the effect of anchor pile in inverted arch for this filling defect. The results show that: (1) The main stress of the filling layer is mainly controlled by the dynamic load of the train and the ground load has small impact on the filling layer. But when the second lining failure occurs, the filling layer begins to bear the ground load and may be destroyed. (2) The structural damage of the filling layer is not controlled by the dynamic displacement but the tensile break. (3) It is feasible to adopt the method of anchor pile reinforcement to reduce the stress level of the second lining and filling layer. The research results have some reference value for the design and disposal defect of deep-buried and heavy-haul railway tunnel in the future.