Monitoring and warning system for ground subsidence of gypsum mine based on fiber sensing

In recent years, the mined-out area resulting in more than 20 goaf collapse disasters in the north Pizhou, Jiangsu Province. The traditional monitoring method of surface soil deformation is difficult to meet the requirement of advance prediction of surface subsidence. In order to solve the lack of monitoring and early warning mechanism of mined-out subsidence in gypsum mining area, a monitoring and early warning system based on fiber sensing technology was developed in this area. According to the results of preliminary investigation, analysis and numerical simulation, the ground collapse mechanism of gypsum mine is deduced, dynamic monitoring of groundwater level, displacement of deep rock and soil mass and microseismic monitoring of bottom aquifer above loose layer were monitored by optical fiber sensor, in the course of monitoring, the alarm will be triggered when the fluctuation of water level and the displacement of rock and soil suddenly exceed the normal fluctuation value or when a strong vibration signal is received, and the effective early warning will be carried out in the early stage of the ground collapse, and can provide adequate lead time for disaster prevention and mitigation efforts. Through the implementation of monitoring and early-warning work, the validity of these monitoring and early-warning means has been verified, which can provide data basis and scientific basis for the monitoring, prediction and prevention of ground subsidence in mining areas, it can also provide reference for prevention, control, monitoring and early warning of ground collapse geological disaster in gypsum mine and other similar conditions.