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为研究裂隙岩体爆炸动载荷作用下裂纹扩展规律,实验采用有机玻璃模型,以炮孔和裂隙相对位置为变量,通过单发雷管加载模型进行相似物理实验。结果表明,当预制裂隙右端圆弧顶点到炮孔中心连线与模型中间穿过炮孔中心的横虚线的夹角θ为0°和90°时,爆生裂纹数量相对较多,45°时爆生裂纹数量最少,但平均长度最长;每组模型总裂纹平均长度在裂隙右端半圆弧顶点到炮孔中心距离L为40mm时达到最大值;0°组各模型最长裂纹均分布在炮孔右侧,而45°和90°组则多分布于炮孔下侧;固定区域内爆生裂纹密度大多小于不定区域内裂纹密度;所有模型预制裂隙两端都能形成翼裂纹,同组模型同端扩展路径相似;L为20~30mm时两端翼裂纹扩展方向一致,L为40~60mm时两端翼裂纹扩展方向多相反;爆生裂纹扩展机制随角度θ变化而有所不同。研究结果可为裂隙岩体爆破设计及爆破参数优化等提供理论依据。
In order to study the crack propagation law under the explosive dynamic load of fractured rock mass, the model of plexiglass was used in the experiment. The relative physical position of the blast hole and the fracture was used as a variable to simulate the physical experiment. The results show that when the angle θ between the line connecting the apex of the prefabricated fissure at the right end of the prefabricated fissure and the center line of the hole passing through the center of the hole is 0 ° and 90 °, The average length of the total cracks in each group reached the maximum when the distance L between the apexes of the semicircular arcs at the right end of the fracture and the center of the borehole was 40 mm. The longest crack in each model in 0 ° group was distributed in the While the 45 ° and 90 ° groups are mostly distributed on the underside of the borehole. The detonation density in the fixed area is mostly smaller than the crack density in the indefinite area. The wing cracks can be formed on both ends of the prefabricated cracks in all models. In the same group The model propagates in the same direction with the same end. When L is 20 ~ 30mm, the propagating directions of both ends of the flaps are the same. When L is 40 ~ 60mm, the propagating directions of the flanks of the flaps are opposite. The propagation mechanism of the crack propagates differently with the angle θ. The research results can provide theoretical basis for the design of blasting rock mass blasting and optimization of blasting parameters.