1, the gas tunnel construction must be the corresponding construction organization design, making the gas control and safety measures.
2, to be excavated by positive step method, arch excavation once forming, timely shotcrete rock closed reduction gas overflow. The excavation must be reduced by blasting, rock surface bumpy caused the local gas accumulation.
3, drilling and blasting excavation must keep drilling, charging less, short footage, quickly spray anchor, strong support, frequently detection, using preact grouting bolt double liquid grouting reinforcement of fractured rock, rock jam, reduce or prevent gas spillover.
4, borehole charge: the coal electric drill drilling, hole depth less than 60 cm, can not charge blasting; hole depth 60-100 cm, lute is not less than half deep deep hole; hole is more than 1 meters, was not less than 50 cm; the hole depth greater than 2.5 meters, was not less than 1 metres.
5, the electric detonation initiation: firstly, using five section electric detonators, electric detonator to fully inserted into the cartridge, instantaneous detonator and detonator shall not be used in the same network; the initiation bus to use copper core insulation wire, don't replace it with bare wire and aluminum wire core, bus using single loop; the detonator in the opening 20 meters, when shooting the power; the same series network detonators must be of the same manufacturer, the same lot, the same brand; the duration of the last paragraph is not more than 130 millisecond detonator.
6, detonators and explosives: must be used to obtain the production license of the detonator for coal mine and coal mine special explosives. Explosives within the salt can reduce power, prevent sparks.
7, blasting Management: ⑴ before and after blasting detonator, explosive quantity to timely inventory, timely recovery of storage or returned, and good blasting records; must be the blast ventilation for more than 15 minutes, by the gun industry first check the shooting scene, there is no danger after other personnel before entering the site, for the stockpile pavement sprinkled (spray) after water, mucking machine then mucking out; the relevant provisions of the drilling, charging, lute and blasting must be consistent with the gas explosion, fire is strictly prohibited by blasting.
8, the wet processing: drilling and jet concrete work to do first after boiling water wind, dust with closed, avoid spark.
9, the arch connecting: all grille and steel arch connecting steel bars shall be by mechanical connections, welded connections.
10, two secondary lining concrete: ⑴ join airtight agent (such as type NF-B sealing agent), enhance the air tightness of lining concrete; the two lining concrete construction work should be inclined to vibration, not vertical vibration; the two lining concrete formwork should be beaten with wooden hammer, prevent sparks.
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