A simulation experimental study on high-pressure air blasting of coal

被引：0

作者：

Chu H. ^{[1
,2
]}

Wang C. ^{[1
]}

Yang X. ^{[1
,2
]}

Yan S. ^{[1
]}

Wei H. ^{[1
]}

Ren Z. ^{[1
]}

Chen Z. ^{[1
]}

Zhu S. ^{[1
]}

机构：

[1] College of Civil Engineering，Henan Polytechnic University, Jiaozuo

[2] Henan Key Laboratory of Underground Engineering and Disaster Prevention, Henan Polytechnic University, Jiaozuo

来源：

Zhendong yu Chongji/Journal of Vibration and Shock | 2022年 / 41卷 / 20期

关键词：

coal damage-fracture; experimental study; high-pressure air blasting (HPAB); simulation coal; the propagation and attenuation law of stress wave;

D O I：

10.13465/j.cnki.jvs.2022.20.007

中图分类号：

学科分类号：

摘要：

High-pressure air blasting ( HPAB) is one type of physical blasting techniques to increase the permeability of the coal seam by instantly releasing high-pressure air to impact the coal. In this paper, a experimental study on the HPAB of simulation coal was conducted using a self-developed HPAB experimental system. To reveal the propagation and attenuation law of stress wave，and the process and mechanism of coal damage-fracture under the action of HPAB, the ultrasonic velocity, strain and cracks propagation speed were tested. Based on the experimental results and the theory of damage fracture mechanics，it can be concluded that the stress waveform generated under the action of HPAB is the same as that generated under the action of explosive blasting. However, the peak stress of the HPAB stress wave is smaller than that of the explosive stress wave. Moreover, the action time and the pulse width of the HPAB stress wave are longer than that of the explosive stress wave, and the HPAB stress wave decays at a slower speed (a = 2 -/m/(1 -/jl)). Under the tensile action of the HPAB stress wave, the initial radial cracks in coal are generated firstly, and the initial radial cracks propagate rapidly at 0. 15 -0. 40 times the speed of the ultrasonic velocity. Subsequently, the initial radial cracks propagate steadily at 0. 12 - 0. 14 times the speed of the ultrasonic velocity with the combined effect of high- pressure air, the methane gas pressure, and the in-situ stress. Finally, the periodic original cracks, which are in the far area of the blasthole，slowly propagate in a small area with the combined effect of elastic stress wave，the methane gas pressure, the in-situ stress and the interaction between parallel original cracks. © 2022 Chinese Vibration Engineering Society. All rights reserved.

引用

页码：54 / 60and157

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