Method for enhancing slotting blasting efficiency of roadway (tunnel) tunneling

Abstract

The invention relates to a method for enhancing the slotting blasting efficiency of roadway (tunnel) tunneling. The method comprises the steps that four empty holes perpendicular to a working face andwith the diameters being 78 mm are dilled in the lower middle part of a roadway (tunnel) tunneling working face, a first explosive charging hole with the diameter being 50 mm is formed in the centerof a connecting line of the empty holes and serves as a first section hole for detonating, and four evenly-distributed second explosive charging holes with the diameters being 50 mm are drilled in a circumference with the radius being 40 cm by taking the center of the connecting line of the empty holes as a circle center and serve as a second section for detonating. According to the technical scheme, an inverse detonating mode is adopted, the first explosive charging hole in the middle and the surrounding second explosive charging holes adopt the mode of hole-bottom detonating, detonating primers are all arranged at the bottom of blast holes, and energy gathering cavities of both detonators and explosive cartridges face towards the outside of the holes, so that the propagation direction ofexplosive detonating waves and the direction of throwing rock are consistent; and on the one hand, complete crushing of the rock can be ensured, on the other hand, it can be ensured that the more crushed rock can be thrown out of the hole through explosive blasting energy, so that the slotting blasting efficiency is effectively improved.

Description

technical field [0001] The invention relates to a method for enhancing the efficiency of cutting blasting in tunnel (tunnel) excavation, and belongs to the technical field of tunnel (tunnel) excavation methods. Background technique [0002] In the existing technology, the excavation section of the quasi-tunnel in the iron mine is about 23.16 square meters. The excavation method is straight hole cutting blasting. The hole utilization rate is within 83%, and 17% of the blast holes are not fully utilized. The blasting effect of the cut holes directly affects the entire excavation single cycle and excavation efficiency, and plays a decisive role in the consumption of excavation costs. The quality of the blasting effect mainly depends on whether the material within the cutting range is completely thrown out according to the expected depth requirement to create a better free surface of the cavity. Contents of the invention [0003] The present invention is aimed at the technica...

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Problems solved by technology

[0002] In the existing technology, the excavation section of the quasi-tunnel in the iron mine is about 23.16 square meters. The excavation method is straight hole cutting blasting. The hole utilization rate is within 83%, and 17% of the blast holes are not fully utilized. The blasting effect of the cut holes directly affects the entire excavation single cycle and excavation efficiency, and plays a decisive role in the consumption of excavation costs. The blasting effect is good or bad, mainly depends on whether the cutting range is completely thrown out according to the expected depth requirements, creating a better free surface of the cavity

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