Evaluation of Water Inrush Hazard in Coal Seam Roof Based on the AHP-CRITIC Composite Weighted Method

Abstract

The more complex the hydrogeological conditions of a mine, the more likely the coal seam is to experience water inrush during the mining process, and the greater the degree of the water inrush hazard. The scientific and reasonable prediction of water inrush in mines with complex hydrogeological conditions is of great significance to the safe and efficient operation of coal mines. Taking the roof water inrush problem of the No. 3 lower coal seam in the Jisan Coal Mine as the research object, the factors affecting the roof water inrush of the coal seam were comprehensively considered from three aspects: the aquifer property, the mining fracture development and the geological structure. The evaluation index system was constructed by selecting 10 factors, including the aquifer depth and thickness, core recovery rate, brittle–plastic rock thickness ratio, number of water-resisting layers, development height of the water-conducting fracture zone, fault density, frequency density, scale index and variation coefficient of the coal seam floor dip angle. At the same time, based on the dual influence of subjective and objective weighting, the scientific and reasonable weight of each factor was ensured. The AHP-CRITIC composite weighting method was used to calculate the comprehensive weight of each factor. Finally, the roof water inrush risk prediction model was constructed. According to the prediction results, the study area was divided into a low-risk area, medium-risk area and high-risk area. Compared with the actual situation, the prediction results were basically consistent with the actual situation, and the prediction results can provide the basis for the prevention and control of water in a coal mine.

Risk Assessment of Water Inrush from Coal Seam Roof Based on the Combined Weighting of the Geographic Information System and Game Theory: A Case Study of Dananhu Coal Mine No. 7, China

“…The analytic hierarchy process (AHP) is a method of multi-criteria decision analysis that breaks down complex decision problems into multiple objectives or criteria and further divides them into hierarchical indicators. Experts use their experience to determine the importance between parts, resulting in a decision matrix which defines the weights of each factor [29,30].…”

Water-Filling Characteristics and Water Source of Weakly Rich Water and Weakly Conducting Water Aquifers in the Changxing Formation after Mining Damage

“…The limestone of the Changxing Formation is commonly exposed within the mining area and is replenished by atmospheric precipitation. Studies by Shi Xianzhi et al [5], Yao Guanghua et al [15], Wang Zaiyong et al [16], Long Tianwen et al [17], and Xiao Lele et al [18] have shown that under conditions of fracture development due to mining activities, the limestone of the Changxing Formation supplied the mining site through channels such as karst and fractures.…”

Bed Separation Formation Mechanism and Water Inrush Evaluation in Coal Seam Mining under a Karst Cave Landform

“…Choosing appropriate methods to determine the weights of various indicators for water inrush in the separated layers is an important way to improve the accuracy of evaluation results The analytic hierarchy process (AHP) and entropy weighting are common methods for determining subjective and objective weights [23,24]. In order to make the calculation of each indicator more reasonable and accurate, and to compensate for the shortcomings of a single weighting method, an improved weighted fusion method is proposed.…”

“…In relation to the safety evaluation of potential mine roof water damage, Wu [22] proposed the "three graphs and double prediction method" to analyze roof water accumulation and improve the accuracy of prediction results. In recent years, other scholars [23,24] have proposed different improvements to this method for various geological conditions, and have searched for suitable roof water inrush risk assessment methods. For example, Li [25] established an indicator system and evaluated the risk of water inrush based on GIS and a network analytic hierarchy process for the karst aquifer in the southwest mining region.…”