Multi-factor Contribution to the Height of Water-conducting Fracture Zone and Mine Zoning for Water Protection in Yushen Coalfield

Abstract

Predicting the Water-conducting fracture zone height (WFZH) and determining the mining zones that require water conservation operations are critical for the mine sustainability. In this paper, mathematical statistics, multiple regression and spatial analysis methods were employed to analyze the mechanisms of longwall parameters contributing to WFZH and construct a nonlinear correlation of WFZH versus mining height, depth of cover, and retreat rate. Based on the WFZH equation and aquifer depressurization threshold, Yushen Coalfield is zoned into different conditions: Under the case 1, the water resources safe exploitation (WRSE) area in the mining area is 4.24×109 m2, accounting for 82%, and Non-WRSE area is 920 835 911.3 m2, accounting for 18%; Under the case 2, the WRSE area in the mining area is 3.87×109 m2, accounting for 77%, and Non-WRSE area is 1.14×109 m2, accounting for 23%; Under the case 3, the WRSE area in the mining area is 3.78×109 m2, accounting for 73%, and Non-WRSE area is 1.38×109 m2, accounting for 27%. The water protection level is further detailed by comparing the three conditions, further suggesting the mine that needs higher focus. The results help provide macro decision-making basis for mine planning and longwall design, enriching the theory and technology for water conservation mining.

Keywords

• yushen coalfield
• multi-factor contribution
• height of fracturing
• mine zoning
• water conservation mining