A Subsection Micro-differential Cutting Blasting Method in Deep Hole Multiple Wedge Straight Hole in Rock Roadway

Abstract

A method of segmented micro-differential cutting blasting in multi-wedge straight holes in deep holes in rock roadways, that is, the segmental micro-differential blasting technology between multi-wedge straight deep hole cutting holes is used to realize step-by-step expansion of the cavity and step-by-step deepening of the cavity, The deep-hole columnar charge segmental differential blasting technology is used to solve the phenomenon of bulging at the bottom of the cavity. This deep-hole cutting blasting method can realize a large cavity and a 3.0m deep cavity, and the rate of cutting large pieces of gangue is small. , The effect of shortening the throwing distance of gangue to 25-30m. According to the detonator of the first squint + six-direction energy-concentrating straight eye section I, the second squint first section + the center straight eye hole II detonator, the second squint second section + the center straight eye bottom charging section + the third squint section III detonator Sequentially detonate to form the final cut cavity, and then use the fourth section detonator to detonate the auxiliary eye, avalanche eye, and bottom eye, and use the fifth section detonator to detonate the peripheral eye to complete the full-section blasting; it can provide a large cavity, expand the free surface, and improve the blasting efficiency. efficiency.

Description

technical field [0001] The invention belongs to the technical field of rock roadway blasting, and in particular relates to a method for segmental differential cutting blasting in deep holes with multiple wedges and straight holes in rock roadways. Background technique [0002] In the excavation of various rock roadways (tunnels), the drill and blast method still occupies the main position in the excavation due to its own advantages. In the coal mine rock roadway excavation in my country, according to the depth of the blast hole, it can be divided into: shallow hole blasting (blasting hole depth <1.8m); medium and deep hole blasting (blasting hole depth 1.8m~2.5m); deep hole blasting Light explosion (blasting hole depth 2.5m~5.0m); ultra-deep hole light explosion (blasting hole depth above 5.0m). When drilling and blasting excavation, most of the drilling rigs in domestic coal mines use 2.6-meter drills, and most coal mine rock roadways generally have a footage of about 2....

AI Technical Summary

Problems solved by technology

[0003] At present, in all kinds of engineering blasting, although deep hole cutting blasting methods such as oblique holes, straight holes, double wedges, and multi-wedges have been explored in the deep hole cutting blasting technology, the single free vertical deep hole blasting such as cutting blasting For hole blasting, due to the clamping effect of the rock at the bottom of the hole, especially the deeper the blasthole, the stronger the clamping effect, there will often be a large number of residual holes after blasting, resulting in obvious bulging in the middle, resulting in digging. It is difficult for the groove depth to exceed 2.6m, which reduces the blasting effect and blasting single-cycle footage, and affects the cutting effect

In addition, when carrying out deep hole blasting, especially when the rock is relatively hard, in order to improve the cutting effect, the holes are usually arranged very densely and the amount of charge is large, resulting in a large amount of charge in one blast and serious damage to the surrounding rock. The blasting shock wave is large, and the gangue throwing distance is long, etc.

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