关键词: 露天煤矿, 低渗透地层, 膜袋注浆法, 帷幕注浆

Abstract: In order to improve the grouting effect of waterproof curtain under complex low permeability geological conditions，based on the typical low permeability strata in a mining area，On the basis of summa⁃ rizing the construction principle and technical characteristics of membrane bag grouting method，the distri⁃ bution characteristics and permeability differences of different strata such as sand layer and soft rock in the mining area are fully considered.And the construction process flow including the key links such as hole com⁃ ponent structure，measuring hole making，grouting component lowering，membrane bag sealing and segment⁃ ed grouting is designed. The field membrane bag grouting test is carried out. The test results show that the membrane bag grouting construction method can flexibly set the size，number and position of the membrane bag，and can reasonably divide the grouting section according to the actual engineering requirements. It has the advantages of wide application range，material saving and environmental protection，high construction ef⁃ ficiency and low cost，which makes up for the shortcomings of traditional compaction grouting technology. The membrane bag grouting method is easy to appear layering phenomenon in the low permeability sand lay⁃ er and soft rock，and the applicability is poor.When grouting in the complex strata of the mining area，the method of low pressure slow injection and intermittent multiple grouting should be adopted，and the grouting flow should not be higher than 2 m³ /h.

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