Grain Size Distribution Effect on the Hydraulic Properties of Disintegrated Coal Mixtures

摘要: In order to better understand groundwater influx and protection in coal mining extraction works, an in-house water flow apparatus coupled with industrial rock testing system, known as MTS 815.02, were used study the effects of grain size mixtures on compaction properties disintegrated, or non-cemented, samples. From Reynolds number evaluation samples different mixtures, relationship between velocity pore pressure gradient differences, it was found that seepage through are non-Darcy type. The porosity specimens be highly affected by compaction, variations also influenced samples’ distribution. It sample decreases increasing decreasing sizes. Grain crushing during observed main cause appearance fine grains, washing away grains consequently contributing factor for weight loss due seepage. tests progression permeability k β increases φ. k-φ β-φ plots show sizes disintegrated getting smaller, there more fluctuations values their corresponding β. value smallest considerably lower than largest grains. Non-Darcy behavior could reduce hydraulic conductivity. porosity, breakage related levels, well arrangement At high decreased strongly, resulting a significant decrease at its full compression state; has slightest effect uniform samples, therefore, indicating treated aquicluding (water-resisting) stratum.