切缝药包爆破定向断裂机理及围岩损伤特性分析 |
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引用本文: | 王雁冰,李书萱,耿延杰,谢平. 切缝药包爆破定向断裂机理及围岩损伤特性分析[J]. 工程科学学报, 2023, 45(4): 521-532. DOI: 10.13374/j.issn2095-9389.2022.04.20.002 |
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作者姓名: | 王雁冰 李书萱 耿延杰 谢平 |
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作者单位: | 1.中国矿业大学(北京)力学与建筑工程学院,北京 100083 |
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基金项目: | 国家重点研发计划资助项目(2021YFC2902103);国家自然科学基金重点资助项目(51934001);中国矿业大学(北京)越崎青年学者资助项目(800015Z11A24) |
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摘 要: | 依据弹性波动理论,结合冲击波在岩石或类岩石介质中的传播规律,建立了切缝药包爆破时切缝方向与非切缝方向的孔壁峰值应力、粉碎区和裂隙区范围之间的比例关系.利用AUTODYN软件建立了切缝药包爆破模型,在其切缝方向与非切缝方向各等间距设置5个测点,对测点处的应力峰值、爆破振动速度峰值以及峰值对应的时间进行了分析.而后基于淮南矿区顾北煤矿的巷道爆破试验,进行了普通药包、切缝药包以及不同周边孔间距的爆破试验,研究了切缝药包以及周边孔间距的大小对围岩损伤度的影响.结果表明,使用切缝药包爆破时,在其切缝方向会产生爆轰产物射流和应力集中,同时会减弱非切缝方向的应力峰值和爆破振动速度,延缓非切缝方向的能量传播速度,减弱非切缝方向的能量传播大小,从而达到定向断裂的目的;通过现场试验可以发现,使用切缝药包比使用普通药包爆破后,围岩的损伤度下降了30%以上;当使用切缝药包爆破时,随着周边孔间距的增大,爆后围岩损伤度呈下降趋势.
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关 键 词: | 切缝药包 应力峰值 爆破振动速度 药包间距 围岩损伤 定向断裂 分形维数 |
收稿时间: | 2022-04-20 |
Directional fracture mechanism and surrounding rock damage characteristics of slotted cartridge blasting |
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Affiliation: | 1.School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China2.State Key Laboratory of Geomechanics and Deep Underground Engineering, Beijing 100083, China3.Gubei Coal Mine of Huaizhe Coal Electricity Co., Ltd., Huainan 232150, China |
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Abstract: | According to the elastic wave theory combined with the propagation law of shock waves in rock or rock-like media, a slotted pipe wall is assumed to be elastic, irrespective of the attenuation process of detonation and shock waves in the coupling medium. The reflection of detonation and shock waves at the slotted pipe and blasthole walls is also assumed to be positive reflections, and the flow rate and internal energy constantly change with time. The proportional relationship between the peak stress of the hole wall, the range of the crushing area, and the fracture area in the cutting and non-cutting directions was established in this study. Moreover, AUTODYN software was used to establish a slit charge blasting model. Five measuring points were set at equal intervals in slit and non-slit directions. The peak stress, peak blasting vibration velocity, and peak arrival time at the measuring points were analyzed. Thereafter, based on the tunnel blasting test of the Gubei Coal Mine in the Huainan mining area, blasting tests of ordinary charge packs, slit charge packs, and varying peripheral hole spacing were performed. The crack state of the surrounding rock before and after blasting was tested through drilling peeping. Then, a two-dimensional graph of the crack development of the surrounding rock before and after blasting was imported into the customized MATLAB box dimension calculation program for calculation. The results before and after blasting were obtained based on the linear fitting curve and the box-counting dimension of the pixel information matrix of the surrounding image of rock burst cracks after blasting. The influence of the size of the slit charge and the surrounding hole spacing on the damage degree of the surrounding rock was also investigated. The results indicate that when the slit charge is used for blasting, the detonation product jet and stress concentration are produced in the slit direction. Further, the stress peak value and blasting vibration speed in the non-slit direction decline, the energy propagation speed in the non-slit direction decreases, and the energy propagation size in the non-slit direction decreases to achieve the goal of directional fracture. The results of the field test indicate that the degree of damage of the surrounding rock is reduced by >30% after using slit charge blasting compared with ordinary charge blasting. When the slit charge is used for blasting, the degree of damage to the surrounding rock reduces with an increase in the distance between the surrounding holes. |
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