Temporal and Spatial Characteristics Analysis of Deformation Along Foshan Subway Using Time Series InSAR

As a city with rapid economic development and urbanization in China's Pearl River Delta region, Foshan has been affected by land subsidence disasters for a long time due to its fragile geological and hydrological conditions. At the same time, the subway in the region is an important tool to alleviate the traffic pressure of the city. The ground subsidence caused by its construction and operation affects the safety of people's lives and property. However, there are not many systematic studies on this aspect in Foshan, and there is insufficient understanding of the settlement law along the subway. This paper uses fixed-point data to monitor the deformation information of Foshan from June 2015 to September 2018. The results show that the surface deformation of Foshan is sporadic, and there is no large-scale settlement funnel. The deformation rate is between 5 mm/a and -20 mm/a, and the settlement rate of local area is over -30 mm/a.Land subsidence is mainly related to unstable geological structures, groundwater extraction and local area construction. Based on the obtained deformation results, this paper also studies the deformation along the subway in Foshan city, and analyzes the settlement of the collapse section of Foshan subway in 2018, and expounds the cause of the difference in the space along the subway. In the time, the model parameters are inversed in the deformation along the subway. This paper provides a reference for the local government to carry out the survey of surface deformation and the early warning of subsidence disasters. And it provides a theoretical basis for the safety monitoring of the normal operation and maintenance of the subway.