Research Progress and Analysis of Grouting Treatment for Safe Mining of Coal in Thick Loose Layer

The thick unconsolidated layers are widely distributed in the eastern mining areas of China. Coal mining is facing severe safety and environmental hazards such as water and sand inrush and surface subsidence. Traditional passive prevention and control methods have the limitations of large waste of resources and low treatment efficiency. Grouting reinforcement and anti-seepage technology has become the core means to solve this problem by virtue of its advantages of actively transforming strata. This paper reviews the development of grouting treatment technology under thick loose layer, analyzes the applicable boundary of the four grouting theories, compares the engineering performance of the two material systems, and summarizes the multi-dimensional evaluation system of ' theory-test-simulation-measurement '. Aiming at the engineering problems such as the low matching degree between the current grouting theoretical model and the spatial variability of thick unconsolidated layers, and the lack of precise control of deep visualization, it is clearly pointed out that the future grouting management needs to focus on three directions : multi-field coupling refinement theory, green high-performance adaptive material research and development, and full-cycle intelligent control based on digital twins. The purpose of this paper is to provide scientific theoretical support and technical reference for coal safety, green and efficient mining under deep complex geological conditions in China.