Segmented unloading method for underground chamber static explosion excavation in rock explosion area

Abstract

The invention discloses a segmented unloading method for underground chamber static explosion excavation in a rock explosion area. The segmented unloading method for the underground chamber static explosion excavation in the rock explosion area comprises the steps that a dense conical cuthole, a horizontal empty hole, a horizontal auxiliary hole and a horizontal periphery hole with different depths are drilled at the front of the tunnel surface to be used as a first stress relief process, and high ground stress is transferred to the interior of rock mass with different depths; then a static rock cracking agent with cyclic penetration is poured into the conical cuthole, the horizontal auxiliary hole and the horizontal periphery step by step, the excavation rock mass is pushed forward expansion pressure more than 30-80 MPa generated by hydration reaction depend on rock cracking agent itself, local stress near the tunnel surface is relieved step by step under the action, the rock mass tobe crushed is subjected to safe static crushing under the condition of no vibration, no noise, no slungshot and no hazards in the excavation process, and a rock explosion control idea of short footage, multi cycle, weak explosion, less disturbance, control of smooth explosion effect and the like at present is meet. The energy accumulation level of stress redistribution caused by rock mass excavation is removed or reduced, and the surrounding rock strength is weakened and the surrounding rock is not damaged excessively.

Description

technical field [0001] The invention relates to the field of geotechnical engineering, in particular to a partial unloading method for static blast excavation of an underground chamber in a rockburst area. Background technique [0002] In the process of excavating underground works in hard and complete high-in-situ stress areas, due to the stress redistribution of surrounding rocks, the elastic strain energy accumulated inside the rock mass is suddenly released, causing rock slices to fly to the chamber at an extremely fast speed. Later, the phenomenon accompanied by a loud sound is called a rockburst. [0003] The rockburst problem caused by excavation in the hard and intact rock mass in the high ground stress area will be a major challenge for the development of underground engineering in my country in the 21st century. During the excavation process of underground engineering, rockburst is the most intense reaction among various instability phenomena of surrounding rock, ...

AI Technical Summary

Problems solved by technology

[0012] At present, many scholars recommend using partial excavation to reduce the occurrence of rockbursts. However, the field practice shows that increasing the number of excavations is not entirely beneficial. Multiple blasting excavations will result in one more chance of encountering rockbursts. Secondary power blasting excavation may even induce shear failure rockburst

[0013] Reinforcement of the surrounding rock only passively resists the adverse consequences of rockbursts. It is difficult to eliminate the adverse consequences of rockbursts that are more than strong by simply strengthening the support stiffness.

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