Monitoring and Analysis of Structural Deformation During Subway Station Construction Interval under Soft Soil-bedrock Conditions

There are insufficient researches on the structural deformation monitoring and evaluation of subway stations during construction intervals under the condition of soft soil-bedrock. The fiber Bragg grating sensing technology was applied in the structural deformation monitoring research during the construction interval of the station. Taking a subway station in Shenzhen as a research case, the optical fiber sensor was installed on the main structure of the station, and the deformation information of the structure during the construction interval was obtained automatically and remotely. The results show that the main structure of the soft soil-bedrock foundation has a certain degree of deformation during the construction interval. During the monitoring period, the maximum strain of the station floor is 62 μɛ, and the maximum deformation of the wall column structure of the second underground floor of the station is 249 μɛ. Wall-column structures located near the soft soil-bedrock interface are affected by both shear and compressive stresses. Therefore, the flexural and shear strength design of the base plate and the bottom wall column should be respectively considered in the subsequent station construction of the soft soil-bedrock foundation.