60 years of investigation on water inrush coefficient: Challenges faced and development directions

Since the birth of the water inrush coefficient in 1964, in spite of it has undergone many improvements and changes in the past 60 years, its main body has always been the main method for predicting and evaluating the danger of bottom water inrush in my country, and has played an important role in ensuring the safety of pressure mining production and promoting the development of pressure mining theory. The inheritance and development of the water inrush coefficient method was reviewed, and the development history of the water inrush coefficient method was summarized. It was considered that the evolution of the water inrush coefficient method mainly revolved around the concept of “effective aquiclude thickness”. The inability to determine the critical water inrush coefficient limited the application of other versions of the water inrush coefficient method. The characteristics and differences of shallow and deep water hazards are explained from the five dimensions of water source, intensity, channel, time and water quality, and the limitations of the water inrush coefficient method under deep mining conditions are pointed out; the improved version is summarized, and the improvement direction of the water inrush coefficient method under deep conditions is pointed out: improvements are made around the lack of specificity, the influence of the thickness of the impermeable layer, and the single consideration factors. Analyzing the concepts of the subject and returning to the proposition of water inrush hazard assessment itself, the hazard assessment should answer two parts: the possibility of water inrush and the degree of harm caused by water inrush; sorting out the factors affecting the hazard of water inrush, and analyzing the defects of the water inrush coefficient method: it does not fully consider important influencing factors such as geological structure and water-richness of aquifers. Looking into the future, the development direction of the water inrush coefficient method is discussed, including forming a combined model with other theories and methods and selecting big data evaluation methods. With the advancement of information technology and the steady progress of the intelligent construction of coal mines, deep learning, machine learning and supporting methods will become the mainstream evaluation methods. In particular, big data evaluation methods under the constraints of physical mechanisms are the future research hotspots.