Constructing a water-blocking layer in the dump sites of an open-pit coal mine is of great significance to improve the water retention capacity of the reclamation area. The permeability law of the water-blocking layer is costly to be analyzed and researched by means of field tests. In this study, the soil-rock mixture samples similar to the water-blocking layer were prepared, and the rock block proportion (RBP) and hydraulic pressure were adopted as test variables to conduct a permeability test, which provided theoretical support for on-site construction. The results show that when the hydraulic pressure is less than the confining pressure, the permeability increases at a steady rate as the rock block proportion increases. When the hydraulic pressure is close to or equal to the confining pressure, penetrating cracks are easily formed between the soil-rock interfaces of the sample with a higher rock block proportion, resulting in a rapid increase in permeability. With the increase of hydraulic pressure, the migration of the internal fine particles in the sample with a rock block proportion of 40% or less leads to the partial cracks closure, which gradually reduces the permeability. The internal structure of the sample with a rock block proportion more than 40% experiences a process in which the permeability decreases with the crack closure to a significant increase due to the penetrating crack formation. In summary, the soil-rock mixture with about 30% rock block proportion is characterized by suitable permeability and stability, which guarantees the construction cost on-site at the same time. In addition, increasing the rolling times of the truck can increase the compaction of the water-blocking layer and reduce the permeability. The roughness and gradation of the rock blocks can improve the permeability and stability of the water-blocking layer.

中文翻译：

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露天煤矿排土场阻水层土石混合料渗透性研究

在露天煤矿的排土场中建造挡水层对于提高填海区的保水能力具有重要意义。阻水层的渗透率定律是昂贵的，需要通过现场测试来分析和研究。本研究制备了与阻水层相似的土石混合料样品，并以岩块比（RBP）和水压作为试验变量进行渗透性试验，为现场提供理论支持。施工。结果表明，当水压小于围压时，渗透率随岩块比例的增加而稳定增加。当液压接近或等于围压时，在岩石块比例较高的样品的土壤-岩石界面之间容易形成穿透性裂缝，导致渗透率快速增加。随着水压的升高，内部细颗粒在岩石块比例为40％以下的样品中的迁移导致部分裂缝闭合，从而逐渐降低了渗透率。岩石块比例大于40％的样品的内部结构经历了这样一个过程，在该过程中，渗透性随着裂缝的闭合而降低，由于渗透性裂缝的形成而显着增加。综上所述，土石混合比约为30％的土石混合体具有合适的渗透性和稳定性，保证了现场的施工成本。此外，增加卡车的滚动时间可以增加阻水层的压实并降低渗透性。岩石块的粗糙度和等级可以提高阻水层的渗透性和稳定性。