Construction method of outburst-prevention jet grouting surrounding pile for railway gas tunnel in coal measure stratum

Abstract

The invention discloses a construction method of outburst-prevention jet grouting surrounding pile of a railway gas tunnel in coal measure stratum. The construction method comprises the following construction steps of judging gas outburst through advanced geological forecast, determining an outburst-preventing drilling arrangement diagram, performing surrounding pile pre-drilling by using a geological drill, only performing jet grouting closed surrounding pile construction on a coal seam section by using a jet grouting machine, performing gas release hole construction in the surrounding pile, performing final verification before coal uncovering, implementing safety protection measures, normally excavating a tunnel and the like; and a closed enclosure pile is adopted for isolating a coal seam, the path that gas in an enclosure pile outer coal seam flows towards an enclosure pile inner coal seam is blocked, the disturbance range of construction in the enclosure pile on the enclosure pile outer coal seam is reduced, only geological drilling is carried out on an outburst coal seam in the enclosure pile for gas pressure discharge, and the outburst prevention range of the gas is greatly reduced. According to the construction method, compared with a traditional outburst prevention measure, the rapid outburst prevention construction method combining blocking and discharging is safer, more efficient, simple and easy to implement.

Description

technical field [0001] The invention relates to the technical field of tunnel construction, in particular to a construction method for outburst-preventing swirl spraying surrounding piles of railway gas tunnels in coal-measure strata. Background technique [0002] Southwest my country is rich in coal resources, and it is very common for tunnels to pass through coal seams in road and rail transportation construction. When the gas pressure in coal seams is too high and disturbed by construction, coal and gas outbursts will bring great danger to the tunnels, and safe and effective gas protection must be adopted. Anti-outburst measures are taken to ensure that the tunnel can pass through the coal seam smoothly and quickly. [0003] According to my country's latest 2019 "Technical Specifications for Railway Gas Tunnels (TB 10120-2019)", tunnels passing through outburst coal seams should be designed and constructed in strict accordance with the principle of "advanced comprehensive ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the above-mentioned problems in the prior art, the present invention provides a construction method of anti-outburst swirl spraying piles for railway gas tunnels in coal-measure strata, which realizes the pressure reduction of coal seam gas pressure by combining "blocking" and "rowing" of coal seams. The release of outburst prevention can quickly achieve the purpose of outburst prevention, and solve the problem that the existing traditional outburst prevention measures need to reduce the pressure of the entire coal seam and discharge it to a safe enough level before continuing construction, resulting in low efficiency of outburst prevention construction and long construction period of outburst prevention.

Images