A probability integral method modified model for accurately characterizing subsidence at the boundary of a mining area.

The "West-East Coal Transmission" project is an important resource allocation project in China, aiming to alleviate the shortage of coal resources in China's economically developed eastern cities. Ensuring coal transportation railway safety is an important part for the smooth running of this project. However, China is a large coal mining country, and some railways inevitably pass through the coal mining influence areas, seriously threatening the structural health of the railways. The probability integral method (PIM) is an official prediction model for mining subsidence in China, while it is difficult to accurately predict the subsidence boundary of a mining area, and cannot scientifically and accurately evaluate the impact of coal mining on the deformation of coal transportation railways passing through the boundary, lacking effective guidance for railway protection. In response to this engineering issue, this paper analyzes the influence of PIM's parameters change on the prediction results, based on which, the probability integral method modified model (PIM-MM) is established, the decreasing step fruit flies optimization algorithm (DS-FOA) used for parameters inversion is also proposed, which realizes the accurate subsidence prediction for the boundary of a mining area. At the same time, with the help of ground observation technique (SBAS-InSAR), the surface subsidence data of the study area was obtained, and the influence factors of the surface subsidence were analyzed, realizing the efficient and real-time monitoring of railway deformation. It can effectively guide the coal mining with the goal of railway protection, and has important social significance and engineering application value for the coordinated development of both.