Cutting blasting method suitable for excavation of high-plastic low-strength rock tunnel

Abstract

The invention discloses a cutting blasting method suitable for excavation of a high-plastic low-strength rock tunnel. The cutting blasting methodis improved from reducing the distance between cuttingholes and changing charging structures of the cutting holes, the distance between the cutting holes is reduced to ensure that the explosion stress wave energy generated by explosives is much higher than the energy required for plastic deformation of plastic rock mass during the explosion, and in addition, the design of auxiliary cutting holes provides support for effectively expanding cutting cavities; and the cutting method is to arrange nine main cutting holes, the center hole is charged, the remaining eight holes are empty holes, the auxiliary cutting holes are distributed in the upper direction, the lower direction, the left direction and the right direction of the nine holeslocated in the center andfour corners of a peripheral square, a small number of charged holes and a large numberof empty holes are combined forcutting blasting, the blasting efficiency is improved, the unit consumption of the explosives is reduced, and the blasting effect of the cutting holes is improved.

Description

technical field [0001] The invention relates to the field of tunnel excavation and blasting, in particular to a cutting and blasting method suitable for tunnel excavation of high-plasticity and low-strength rocks. Background technique [0002] For large-scale infrastructure and energy development projects such as water conservancy projects, tunnel projects, and mining projects, the primary construction process is the excavation of foundations and underground caverns. At present, tunnel excavation in water conservancy projects mainly adopts notch blasting. The function of notch blasting is to provide a free surface for the blasting of subsequent blastholes after the blasting of notch hole explosives throws rocks. Expansion provides compensation space. Therefore, whether the cutting is successful or not directly affects the blasting effect of the tunnel, and the depth of the cutting directly affects the cycle footage of the roadway excavation, which is the key to the success ...

AI Technical Summary

Problems solved by technology

[0018] The technical problem to be solved by the present invention is to provide a cutting blasting method suitable for tunnel excavation in high-plasticity and low-strength rocks, aiming at the failure of cutting or digging under the conditions of high-plasticity, low-strength or soft-hard rock formations by traditional cutting blasting methods. The disadvantages such as high cost of the slot, improve the blasting effect of the slot hole, improve the blasting efficiency, and reduce the unit consumption of explosives

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