中低速冲击载荷下巷道内裂纹的动态响应

发布时间：2018-05-28 14:27

  本文选题：岩石力学 + 巷道　； 参考：《岩石力学与工程学报》2017年06期

【摘要】：由于爆破开挖,巷道内常含有径向裂隙,并影响巷道的稳定性,为了详细地研究含径向裂纹巷道在冲击载荷作用下的动态断裂行为,采用砂岩材料制作巷道模型试样进行中低速冲击动态断裂试验,并采用AUTODYN有限差分软件进行数值模拟分析。分析巷道对称轴线上的径向裂纹在冲击荷载作用下的扩展特性及止裂现象,并采用试验 数值 解析法计算出裂纹的起裂韧度及扩展速度等参数。研究结果表明:(1)巷道围岩在静力载荷作用和动力载荷作用下的破坏行为有较大差异,动力载荷下破坏仅是裂纹尖端处的起裂、扩展;而静力载荷下破坏除了发生在裂纹尖端处,也会在巷道拱肩、拱脚及两侧帮处发生破坏。(2)巷道对称轴线上的裂纹在冲击载荷下的扩展路径大致沿着裂纹的原方向扩展,扩展路径中存在明显的止裂现象。(3)采用试验 数值 解析法能够较好地计算出裂纹的起裂速度及扩展速度,进一步采用位移外推法能够求解出巷道内裂纹的动态应力强度因子时程曲线,利用测试的裂纹起裂时间确定起裂韧度。
[Abstract]:In order to study the dynamic fracture behavior of roadway with radial crack under impact load in detail, there are radial cracks in roadway due to blasting excavation, which affects the stability of roadway. The dynamic fracture test of medium and low speed impact was carried out by using sandstone material to make model sample of roadway, and the numerical simulation analysis was carried out by AUTODYN finite difference software. The propagation characteristics and crack stopping phenomena of radial crack on the symmetrical axis of roadway under impact load are analyzed. The crack initiation toughness and propagation velocity are calculated by means of numerical method. The results show that the failure behavior of roadway surrounding rock under static load and dynamic load is quite different. The failure under dynamic load is only the crack initiation and propagation at the crack tip, but the failure occurs at the crack tip under static load. There will also be damage in the arch shoulder, arch foot and both sides of the tunnel.) the propagation path of the crack on the symmetrical axis of the roadway under impact load is approximately along the original direction of the crack. The crack initiation velocity and propagation velocity can be well calculated by using the experimental numerical analysis method. Furthermore, the time-history curve of dynamic stress intensity factor can be calculated by displacement extrapolation, and the crack initiation toughness can be determined by the measured crack initiation time.
【作者单位】： 四川大学能源工程安全与灾害力学教育部重点实验室;四川大学建筑与环境学院;
【基金】：国家自然科学基金资助项目(11672194) 四川省科技计划项目(2014JY0002) 成都理工大学油气藏地质及开发工程国家重点实验室资助项目(PLN1505)~~
【分类号】：TU45
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本文编号：1947073