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    It is extremely difficult to dig a roadway in an aquifer or a fracture zone. The water in the roadway not only deteriorates the working conditions, but also affects the blasting and other operations. At this time, it is necessary to first control the water, to clarify the hydrogeological conditions, to adopt various drainage and drainage measures, and to use waterproof explosives and non-electric detonation systems to ensure safe construction. When the aquifer has good stability, the lithology is moderately hard, and the water content is large (>15t/h), it is necessary to drill holes and discharge water, or to open the water discharge road at a lower position near the roadway to drain the water. When it is below ~10t/h, it can be drilled normally.
    B working face pre-grouting construction method
    When the water-bearing rock mass is extremely broken or gravel layer and the water content is more than 10t/h, semi-fluid or drift sand can be formed. At this time, it can not be constructed by the common method, and it is extremely effective to use the working surface to pre-slurry and stop the water.
    The 560 main plane of Shirenyu tungsten mine was drilled to 125m to encounter a 1.5m wide extremely fractured fault zone with water inrush and muddy sand and breccia. In order to prevent landslide, the working surface is pre-grouted (the slurry is a mixture of wood ammonium and cement), and the excavation starts three days after grouting, and the fault has been consolidated and stopped. The short-section excavation method with shallow holes and less charge is used to safely pass the water-bearing fault-breaking belt in only 6 working classes.
    Grouting equipment layout, parameter selection and calculation, materials, etc.
Roadway construction in aquifer and flowing sand layer
    A drilling water release construction method