An active prevention and control method for rockburst in gas tunnels under high ground stress

Abstract

The invention discloses an active prevention and control method for rockbursts in gas tunnels under high ground stress, belonging to the technical field of rockburst prevention in gas tunnels. The method utilizes the advanced geological prediction of the tunnel to determine the location and range of the rockburst section of the surrounding rock of the tunnel and the coal-excavation section. . For the rockburst section, advanced center holes, directional holes and wedge-shaped grooves are arranged to perform multi-hole slotted directional hydraulic fracturing operations and hydraulic fracturing operations; for the coal-exposing section, advanced fracturing holes, directional holes and wedge-shaped grooves are arranged, Carry out multi-hole slotted directional hydraulic fracturing operations and hydraulic fracturing operations, and then conduct gas drainage and outburst mitigation assessment. The invention ensures the safety of staff and equipment, maintains the stability of the surrounding rock, achieves the purpose of preventing rockburst and gas dynamic disasters, and maximizes the construction efficiency of the gas tunnel. The invention solves the problems of rockburst and gas dynamic disasters in high stress areas of gas tunnels caused by excavation activities under high ground stress conditions, and has obvious effects and wide practicability.

Description

technical field [0001] The invention relates to the technical field of prevention and control of rockbursts in gas tunnels, in particular to an active prevention method for rockbursts in gas tunnels under high ground stress. Background technique [0002] With the implementation of my country's western development strategy and the overall speed-up in the southwest region, the construction of the western or western traffic infrastructure marked by expressways is in full swing. The terrain in Southwest China is relatively undulating, with plateaus, mountains, hills and basins as the main landforms. The topography and landforms not only increase the cost of expressway construction in Southwest China, but also cause many road sections to pass through mountains. Southwest China, on the one hand, is located in the mountains and valleys, with extremely deep buried depth and extremely high ground stress level; on the other hand, coal resources are abundant and widely distributed, and...

AI Technical Summary

Problems solved by technology

Southwest China, on the one hand, is located in the mountains and valleys, with extremely deep buried depth and extremely high ground stress level; on the other hand, coal resources are abundant and widely distributed, and many expressway tunnels pass through the coal seam vertically or basically perpendicularly to the coal seam. Due to the complex geological structure of coal-measure strata, the existence of high ground stress and high gas pressure, and the frequent disturbances affected by excavation, the dynamic response characteristics are more complicated. explosion disasters, causing serious economic losses and adverse social effects

[0003] Due to the current lack of research on gas tunnels, the highway infrastructure team lacks understanding of rockbursts in gas tunnels, and the research on rockburst disasters in gas tunnels mainly focuses on risk assessment, construction safety management, and monitoring of surrounding rock deformation. The scientific, reasonable and safe prevention and control measures for rockburst in gas tunnels under high ground stress are far behind the development of on-site production practice

[0004] In order to solve this problem, the existing measures mostly adopt methods such as passive strengthening of support to ensure the stability of the roadway surrounding rock with a hard roof, or relieve the high stress state of the tunnel through active drilling and blasting and water injection weakening. The protection method cannot fundamentally solve the occurrence of rockburst dynamic disasters, and is only suitable for weak to medium rockburst situations; while the active forced blasting caving technology has potential safety hazards for gas tunnels, and is likely to cause gas dynamic disasters; Rockburst mainly occurs in high-strength and low-permeability rocks with good integrity. Water injection softening cannot effectively inject water into the rock mass, and it is often used as an auxiliary means of drilling and blasting

The existing gas tunnel engineering practice shows that conventional rockburst prevention and control methods are difficult to achieve the expected results

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