Mine gallery driving cut blasting method

Abstract

The invention relates to a mine gallery driving cut blasting method which includes the steps that a center blasting hole perpendicular to a working plane is drilled in the center of the gallery driving working plane, five to eight evenly-distributed peripheral holes are drilled in the circumference with the center blasting hole of the working plane as the circle center and the radius ranging from 9 cm to 12 cm, the depth of the center blasting hole is 20 cm-40 cm larger than the depths of the surrounding peripheral holes, the depths of the surrounding peripheral holes are equal, the center blasting hole and the surrounding peripheral holes are parallel to each other, the center blasting hole serves as a powder filling hole, the surrounding peripheral holes are hollow holes, hole openings are packed with stemming after the center blasting hole is filled with an explosive reel and a blasting cap connected with an explosion conducting pipe, when explosives in the center blasting hole are detonated, the hollow peripheral holes serve as free surfaces and compensation space, and the aim of breaking and throwing rock in a cutting frame is achieved; due to the fact that the depth of the center blasting hole is 20 cm-40 cm larger than the depths of the surrounding peripheral holes, the rock throwing force is strengthened, the rock is completely thrown out, and the cutting effect is improved and guaranteed.

Description

Technical field [0001] The invention relates to a mine roadway or tunnel excavation technology, in particular to a mine roadway excavation and blasting method. Background technique [0002] Most of the underground metal mines in my country are small and medium-sized mines. Most of the tunnels excavated are of small section. The tunneling method is shallow cut blasting. Because of the small section, the rock clamp is large, the blast hole diameter is small, and the one-time blast hole The depth is limited, and the blast hole utilization rate is generally within 85%, and 15% of the blast holes are not used, which affects the tunneling effect and efficiency. In the case of restricted aperture and cross-section, the quality of the blasting effect and the utilization rate of blast holes depend on the quality of the cutting effect; the failure of the cutting blasting will lead to failure of the blasting in the tunneling, which will affect the entire tunneling Circulation and excavation...

AI Technical Summary

Problems solved by technology

When cutting and blasting, firstly, due to the effect of rock clamping, the space is small, and the broken rocks after blasting cannot be completely thrown out of the cutting frame, and sometimes crowding occurs, which affects the blasting effect; There are a lot of charges in the gun hole, and the cost is high, but the cutting effect is poor, resulting in a relatively low utilization rate of the blast hole, and the cutting depth is limited, which affects the tunneling efficiency

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