Small-hole reinforced fracturing grain and single-surface hoop slit grain combined cutting undermine method

Abstract

The invention discloses a small-hole reinforced fracturing grain and single-surface hoop slit grain combined cutting undermine method, which comprises the following steps of: 1) drilling; 2) charging:enabling central cutting undermine holes to use a decked charge structure and the small-hole reinforced fracturing grain, filling a second-decked small-hole reinforced fracturing grain into the bottom of each central cutting undermine hole, then, immediately filling tap-hole clay of which the length is 400-500 mm, then, filling a first-decked small-hole reinforced fracturing grain, finally, blocking by the tap-hole clay, filling a second-stage single-surface hoop slit grain into wedge-shaped cutting undermine holes, blocking by the tap-hole clay, filling third-decked common explosive in auxiliary holes, blocking by the tap-hole clay, filling four-decked common explosive in caving holes, blocking by the tap-hole clay, filling five-decked common explosive in surrounding holes, and blockingby the tap-hole clay; and 3) blasting. According to the method disclosed by the invention, the volume of a cutting undermine cavity can be enlarged, a free surface is increased, a surrounding rock clamping function is lowered, and a blast hole use ratio and an explosive energy use ratio are improved.

Description

technical field [0001] The invention relates to the technical field of blasting, in particular to a combined cutting method of a small hole reinforced fracturing charge and a single-side circumferential slit charge. Background technique [0002] Cutting in roadway blasting is the key to determine the overall rock-breaking effect and the size of the cycle footage. A reasonable cutting method is conducive to the blasting of the rock mass to form a cavity, and provides a good free surface for the subsequent blasting to achieve a good blasting effect. With the depletion of shallow mineral resources, the development of mineral resources gradually moves to deep, inevitably encountering in-situ stress. The main difficulties faced in cutting and blasting in deep hard rock roadways are as follows: first, the damage range of the traditional charge structure is limited: the hard rock itself is difficult to crack, and the deep ground stress will inhibit rock blasting and cracking; Sin...

AI Technical Summary

Problems solved by technology

The main difficulties faced in cutting and blasting in deep hard rock roadways are as follows: first, the damage range of the traditional charge structure is limited: the hard rock itself is difficult to crack, and the deep ground stress will inhibit rock blasting and cracking; Single surface: only the working surface is used as a free surface, and the inability to provide sufficient expansion space is also the main reason for the poor cutting effect; the third is the clamping effect: the clamping effect of hard rock itself is relatively large, and with the depth of mining increase, the in-situ stress makes the clamping effect of the surrounding rock significantly increase

These reasons make it difficult to obtain a larger cutting cavity during cutting blasting in deep hard rock roadways, which in turn leads to relatively low blasthole utilization and explosive energy utilization in the subsequent blasting process

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