285 / 2018-04-27 11:25:11

A novel conceptual model of fracture evolution patterns causing water leakage

morphological evolution; fracture arch; coal mining; water loss

矿山安全科学理论与应急救援 > 矿山安全科学理论

The dynamic evolution of mining-induced fractures in overlying strata caused by mining have a non-ignorable effect on engineering safety and water loss from an overlying aquifer. To clarify the evolutionary patterns of fractures due to first and periodic weighting induced by coal mining, W-shaped fracture arch models, were developed to explain and prevent water leakage during the mining process. With the hypothesis of the conceptual models of W-shaped fracture arch that considering the subsequent consolidation process from caving of the overlying strata or not, it showed the evolutionary process of the morphological tendency in fracture arches and characteristics in different directions. It was found that mining-induced fractures evolve in W-shaped mode and develop both upward and forward with the advance of the mining face. Based on these models, we were able to identify the best developed part of the overall fracture evolution, D1EF and E1F1GH, which are the key fracture paths for water to leak after the closure phase of fractures. Combined with a creative simulation experiment of similar material including two comparative mining models, which are normal mining model and the model of the prefabricated fracture arches, the dome-shaped morphological evolution of this conceptual model was well reflected in the range of 20~40 m away from the initial mining location. The presented models may provide an idea to help settle conflicts related to the dynamic evolution of mining-induced fractures and the loss of water resources during mining process.