Mechanisms on Mine Water Loss Based on a Theory of Mining-Fractures Development Pattern

摘要

Longwall mining could inevitably induce the generation of fractures in the overlying strata, the dynamic development of which is believed to be one of the most primary factors controlling groundwater leakage. A hypothesis, triangle fracture arch theory, was proposed for the evolution law of mining-induced fractures, considering two cases of ignoring compaction of gob with successive weightings or not. A connection between the evolution of mining-induced fractures, triangle fracture arch and groundwater leakage was developed. In conjunction with practical experience the first two double-stage arches happening in first weighting and periodic weighting for the first time would be seemed as the key parts of the whole fracture development by means of this theory, which led the widening of some fracture pathways for water to flow. Insight into the development of mining-induced fractures can help us know when, where, and how the mining-induced fractures develop and determine key fracture pathways controlling groundwater leakage paths during longwall mining, providing important theoretical basis for safe mining.