Control of deformation of operating subway station induced by adjacent deep excavation

It was shown by the monitored data that uneven deformation would be induced by deep excavation adjacent to one side of the operating subway station.According to the practice of deep excavation adjacent to a subway station in Shanghai,FLAC-3D was employed to establish a numerical model to simulate the deep excavation.The results were in good agreement with the field test data.Effects of relevant construction methods on the deformation of the subway station were analyzed and presented.It was demonstrated by the theoretical results that the application of underpinned piles,revolving-spraying piles and cement-mixed piles in excavation side and partitioning excavation were the effective measures to control the deformation of the operating subway station.The lateral deformation of underground retaining walls would decrease with the increase of depth of reinforcement,but the vertical deformation increased with the increase of depth of reinforcement due to the contact friction force between the retaining walls and the body of reinforcement.