煤矿岩巷爆破掘进过程中周边眼对裂纹扩展止裂机理

发布时间：2018-04-19 23:02

本文选题：爆炸动载荷 + 周边孔　；参考：《煤炭学报》2017年07期

【摘要】：周边眼在岩巷光面爆破中可以使巷道表面相对光滑完整,同时它对岩体内原生裂纹或爆生裂纹的扩展可能起到止裂的作用。为探究周边眼的止裂作用机理,针对爆破开挖过程中不同间距周边眼对原生裂纹扩展的止裂问题进行了实验及数值模拟研究。实验采用带中心装药孔、预制裂纹(原生裂纹)及两个简化周边眼的有机玻璃圆形试件,观测原生裂纹在周边孔止裂作用下的起裂-扩展-止裂效果。采用AUTODYN软件进行了数值模拟研究,岩石采用线性状态方程(EOS),强度模型为Elastic,失效准则为最大拉应力准则(MMTS),并在扩展路径附近设置观测点,以观测这些点的应力随周边眼间距变化的规律。通过实验及数值模拟结果分析得出:(1)在两周边眼间会产生与裂纹扩展方向垂直的压应力,对裂纹扩展的确能够起到止裂作用;(2)不同的周边眼间距,在周边眼间产生的压应力不同,导致不同的止裂效果;(3)周边眼间距越小,产生的压应力越大,对裂纹扩展的止裂效果越好。
[Abstract]:The surrounding hole can make the roadway surface relatively smooth and complete in the smooth blasting of rock roadway, and it may play a role in stopping the crack propagation of the primary crack or explosive crack in the rock body at the same time. In order to investigate the mechanism of crack arrest in peripheral eyes, the experimental and numerical simulation of the primary crack propagation of peripheral holes with different spacing during blasting excavation was carried out. In the experiment, the effects of initiation, propagation and crack arrest of primary cracks on the primary cracks under the action of the peripheral holes were observed by using two round specimens of plexiglass with central charge holes, prefabricated cracks (primary cracks) and two simplified peripheral eyes. The numerical simulation is carried out by using AUTODYN software. The rock is simulated with the linear equation of state (EOS), the strength model is Elastictic model, the failure criterion is the maximum tensile stress criterion and the observation point is set up near the extended path. In order to observe the variation of the stress of these points with the distance between the peripheral eyes. Through the analysis of the experimental and numerical simulation results, it is concluded that the compressive stress between the two peripheral eyes will be perpendicular to the direction of the crack growth, and the crack propagation can indeed be prevented by different peripheral eye spacing. The smaller the distance between the eyes, the greater the compressive stress and the better the effect on crack propagation.
【作者单位】：四川大学建筑与环境学院;深地科学与工程教育部重点实验室;
【基金】：国家自然科学基金资助项目(11672194) 四川省科技计划资助项目(2014JY0002) 油气藏地质及开发工程国家重点实验室资助项目(PLN1202)
【分类号】：TD235.1;TD263.3

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