Comprehensive Prevention and Control Technology for Overlying Goaf Water Under Complex Conditions

Datong Mining Area has two coal-bearing formations that are Jurassic system and Permo-Carboniferous system, and the upper Jurassic coal seam was mined a long time ago and the resources are nearly exhausted. A large number of water is accumulated in low-lying goaf, which caused serious threat to the mining of the lower part of Permo-Carboniferous coal seam. According to the empirical formula of overburden rock damage theory, we calculate the working face mining height of "three zones". The height of the "three zones" was verified and modified by technical means of drilling peep and separation monitoring; combined with hydrogeololgy conditions of Tongxin Mine, we analyze and evaluate the risk of goaf water inrush. We propose and use the comprehensive detection and three-dimensional prevention technology to drain goaf water of 7.2 million m³, which ensures the safety of mine exploitation.