Key points of safety technology for the hottest ga

Key points of safety technology for gas tunnel

1) during tunnel construction, as long as there is gas in the tunnel, the construction shall be carried out according to the gas tunnel from l0rn before passing through the gas layer to l0rn after passing through the gas layer

2) there is gas outburst. 2. If the machine is not used for a long time after the experiment, in addition to explosion-proof equipment, there should also be anti outburst measures and corresponding equipment in the dangerous work area

3) establish a strict gas prediction system to dynamically monitor gas according to regulations

4) during excavation and support, in addition to considering the construction progress, rock stratum conditions, construction machinery, excavation section factors, it is also necessary to consider the impact of blasting operations on surrounding rock and blasting effects

(1) the positive bench method is adopted for the excavation of gas tunnel. The bench length depends on the geological and construction conditions. Generally, the long bench is better, which can form the upper roadway ventilation as soon as possible. The gas is lighter than air and accumulates on the top of the tunnel. Coal mine safety explosives and instantaneous power detonators must be used for tunnel excavation blasting. When millisecond electric detonators are used, the delay time of the last period shall not exceed 130ms

(2) adopt smooth blasting, strive to be round and smooth around the excavation, and try to avoid gas accumulation, especially at the top, such as pits, cavities and dead corners

(3) after excavation, spray anchor support shall be carried out in time to close the surrounding rock and block the rock gap to prevent gas from continuing to overflow

(4) adopt closed composite lining with inverted arch or thickened bottom. The thickness of initial support should not be less than 15cm, and the thickness of secondary lining should not be less than 40cm. Using air tight concrete to pour in place and strengthen tamping is not only conducive to construction safety, but also conducive to the safety of the tunnel. Generally, the pressure measurement error caused by sample bias and irregularity may take 10 to 20 years to complete and operate after completion

5) pay attention to ventilation in the tunnel. First, dilute and dilute gas; The second is to prevent gas from staying in corners and holes

6) the construction machinery and electrical equipment entering the tunnel should have explosion-proof or explosion-proof performance, and the appearance of the machines and tools should have obvious explosion-proof "each face has its own emotion and story inspection and approval mark. For ordinary common non explosion-proof electromechanical equipment, it is strictly prohibited to enter the gas tunnel for installation and use