Cut blasting optimal design method under high crustal stress condition

Abstract

The invention discloses a cut blasting optical design method under a high crustal stress condition. The cut blasting optical design method is characterized by comprising the following steps: 1) determining the direction of maximal main stress on a tunnel face and the direction of minimal main stress on the tunnel face; 2) designing a rhomboid cut blasting hole according to the direction of the maximal main stress and the direction of the minimal main stress, wherein the rhomboid long diagonal line is the same as the direction of the maximal main stress, and the rhomboid diagonal line is the same as the direction of the minimal main stress; 3) forming a central hole in the center of a rhomboid surface according to the arrangement mode of the rhomboid cut blasting hole; and 4) detonating a cutting hole outside and then detonating explosives in an empty hole, thereby achieving the effect of throwing rock mass. The cut blasting design method has the beneficial effects that: the problem that rock mass cut blasting under the high crustal stress condition is difficult is overcome through the design of the cutting hole and the central hole, and the effect of releasing pressure of the deeprock mass can be achieved, so that energy inside some rock mass can be released untimely, and occurrence probability of rock burst can be favorably reduced.

Description

Technical field [0001] The invention relates to a cutting blasting optimization design method under high ground stress conditions, and belongs to the technical field of deep rock blasting. Background technique [0002] In water conservancy, hydropower, transportation and mining projects, it will be encountered in the use of drilling and blasting to excavate deep rock masses. Due to the high ground stress, the deep rock mass is subjected to high ground stress during the cutting and blasting excavation process. Difficulties arise when blasting and excavating deep rock masses. According to existing researches, the magnitude of in-situ stress and the anisotropy of damage caused by the difference between the maximum principal stress and the minimum principal stress are the main reasons for the difficulty of blasting excavation in deep rock mass cutting. Due to the large buried depth of the deep rock mass, in addition to the self-weight stress, it is also subject to tectonic stress. U...

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Problems solved by technology

[0003] In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide a method for optimal design of cutting blasting under high ground stress conditions, making full use of the crack cracking direction and law between the cutting blast holes in the deep rock mass cutting blasting, Solve the problem of difficult excavation by deep rock mass cutting blasting

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