Abstract:
In order to explore the surface movement deformation characteristics of coal seam mining, this paper takes the 132201 working face as the background of the project, and conducts the on-site measurement of the surface movement deformation data by setting up a continuous monitoring system of GNSS.The study set up reference points at the edge of the mining area, and regularly carried out level surveys and GNSS elevation corrections, while three level reference points were buried in the stable area on the periphery of the mining area to ensure that no subsidence would occur as the starting point of level surveys.A GNSS reference station was also set up outside the expected subsidence range to automatically monitor the surface subsidence and deformation in real time during the mining period.The station design adopts an efficient linear layout, with a total of four GNSS monitoring points(GP1 to GP4) to capture the deformation dynamics of the roof overburden during the working face mining process.The monitoring results show that the surface movement process has gone through three stages of initiation, activity to decline, and each stage has distinctive characteristics, reflecting the initial, accelerated and stable process of the surface response, respectively.As the working face advances, the movement of the overlying rock strata has spread to the surface, the subsidence basin is expanding and the degree of surface subsidence is intensifying.Analyses show that the complexity of surface movement and deformation stems from the combined effect of multiple factors, including mining width, advance rate, coal seam thickness, mining depth and the nature of the surface overburden.These factors are intertwined with each other and jointly determine the spatiotemporal distribution and intensity changes of surface subsidence.Based on the detailed subsidence, displacement and deformation data, this study not only reveals the current state of surface deformation in the study area, but also provides a strategic framework for scientific prediction and control of surface movement and deformation in similar mining areas through trend prediction.