Integrating the hierarchy-variable-weight model with collaboration-competition theory for assessing coal-floor water-inrush risk

Coal-floor water-inrush accidents have become increasingly serious with the increase of mining depth, threatening mining safety in China. This study presents a mathematical assessment method for coal-floor water-inrush risk integrating the hierarchy-variable-weight model (HVWM) with collaboration-competition theory (CCT). Compared with the variable-weight model (VWM) which adjusts weights of main controlling factors only once, the HVWM can readjust the weights of the factors according to assessment needs. The CCT embodies the relationship among multiple controlling factors that influence coal-floor water-inrush. The HVWM-CCT model is applied to the eastern mining area of the Liuzhuang Coal Mine in South China. First, variable-weights of bottom-layer main controlling factors are calculated based on the VWM. Second, top-layer main controlling factors are constructed according to the CCT. Third, variable-weights of top-layer main controlling factors are calculated using the HVWM. Subsequently, the HVWM-CCT model is established to classify risk grades, and the No. 1 coal-floor water-inrush risk in the eastern mining area of the Liuzhuang Coal Mine is divided into five grades. Then, the VWM model is contrasted with the HVWM-CCT model, and a differences table is obtained between the two models. Finally, the verification of water-inrush points, revealed points, and observation results indicate that the HVWM-CCT model is more reasonable compared with the VWM model. The HVWM-CCT model has great potential for assessing the risk of coal-floor water-inrush.