冲击载荷下层状岩体动态断裂行为的模拟试验研究

发布时间：2019-07-17 16:39

【摘要】：采用有机玻璃和环氧树脂两种材料组成的试件模拟层状岩体,对层状岩体的动态断裂行为进行了动态焦散线三点弯曲冲击试验研究。试验结果表明,裂纹扩展到层理面时,不是直接穿过层理面沿原扩展方向继续扩展,而是产生一定的偏移后再继续扩展,其偏移距离与预制裂纹和层理面夹角有关,预制裂纹与层理面夹角越大,裂纹的偏移距离越大;当预制裂纹与层理面夹角90°时,裂纹穿过层理面后只产生一条偏移裂纹,而夹角为90°时,裂纹扩展至层理面后将产生两条偏移裂纹,并且这两条裂纹轨迹几乎对称;裂纹扩展过程中,随着裂纹尖端距层理面的距离减小,裂纹尖端动态应力强度因子Kd1和裂纹扩展速度v均逐渐减小,说明层理面对裂纹的扩展起阻碍作用,预制裂纹与层理夹角越大阻碍作用越大。研究结果对工程实践有重要的参考价值。
[Abstract]:The dynamic fracture behavior of the layered rock mass is studied by the three-point bending impact test on the dynamic fracture behavior of the layered rock mass by using the test piece composed of the organic glass and the epoxy resin. The test results show that when the crack is extended to the bedding surface, it is not directly through the bedding surface to continue to expand in the original expansion direction, but a certain offset is generated to continue to expand, the offset distance is related to the included angle between the pre-cast crack and the bedding plane, the larger the included angle between the pre-cast crack and the bedding plane, The larger the offset distance of the crack, when the included angle of the prefabricated crack and the bedding plane is 90 掳, only one offset crack is generated after the crack passes through the bedding surface, and when the included angle is 90 掳, two offset cracks will be generated after the crack is extended to the bedding surface, and the two crack trajectories are almost symmetrical; In the process of crack propagation, as the distance between the crack tip and the bedding surface is reduced, the dynamic stress intensity factor Kd1 and the crack propagation velocity v of the crack tip are gradually reduced, indicating that the bedding faces the propagation of the crack, and the greater the angle of the pre-cast crack and the bedding is. The results of the study are of great reference value to the engineering practice.
【作者单位】：中国矿业大学(北京)力学与建筑工程学院;
【基金】：国家自然科学基金面上项目(51374210)
【分类号】：O346.1

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