A Discrimination Method for Water Conservation Coal Mining Based on the Thickness of Equivalent Water Resisting Layer

Abstract

The invention discloses a water-retention coal-mining indentifying method based on the thickness of an equivalent water-resisting layer. The water-retention coal-mining indentifying method based on the thickness of the equivalent water-resisting layer comprises the specific steps that the thickness M of each rock stratum of overlying strata and the total thickness M of the overlying strata aredetermined; a permeability coefficient K of the each rock stratum after mining is tested; an equivalent permeability coefficient K<v> of the overlying strata is calculated; the water level depth H<0> and the recharge capacity V (recharge) of the of a water-bearing stratum are determined; the water head height deltaH of the water-bearing stratum after mining is determined; the thickness M of thecritical equivalent water-resisting layer capable of achieving water-retention coal-mining is calculated; and the thickness M (equivalence) of the critical equivalent water-resisting layer is compared with the total thickness M of the all strata from a coal seam roof to the water-resisting layer, and finally the feasibility of a coal seam to achieve water-retention coal-mining is identified. Based on the change of the hydraulic characteristic parameters such as the overall permeability, leakage, and the permeability coefficient of the overlying strata before and after mining, the direct indentifying method for the feasibility of water-retention coal-mining is provided from the water-resisting property of the rock strata, the a water-retention coal-mining indentifying method is more accurate, convenient and high in filed practical-application.

Description

technical field [0001] The invention relates to the technical field of coal mining, in particular to a water-retaining coal mining discrimination method based on the thickness of an equivalent water-resisting layer. Background technique [0002] In recent years, the impact and damage of coal mining on water resources and the ecological environment have attracted more and more attention at the national level. Improper mining activities can easily cause serious damage to the overlying rock and large-scale development of fissures, which in turn will cause serious ecological and environmental problems such as increased leakage of overlying rock, loss of shallow water resources, dry rivers, and land desertification. Especially with the westward shift of the national energy strategy, the northwestern regions of China, such as Xinjiang, Inner Mongolia, and Ningxia, have become the main production areas of national coal production in the future. On the one hand, the coal seams in t...

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Problems solved by technology

[0005] ① Existing research does not start from the perspective of the overall overlying rock (all strata from the water-resisting layer to the coal seam roof), pays more attention to the stability or water-repellent property of a certain rock stratum, and does not consider the water-repellent and water-blocking capabilities of other strata of the overlying rock;

[0006] ② It is mainly based on the height of the water-conducting fissure zone, the thickness of the effective protective layer, and the calculation of the deformation of the water-resisting layer. By analyzing the instability and damage of the overlying rock structure, the water-repelling property of the overlying rock is indirectly judged. The method of judging the feasibility of water-retaining coal mining is directly given from the perspective of hydraulic characteristics such as permeability coefficient

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