爆生裂纹与层理缺陷相互作用的实验研究

发布时间：2019-06-12 07:04

【摘要】：为了研究爆生裂纹与层理缺陷的相互作用机制,采用新型数字激光动态焦散线实验方法对含层理岩体在爆炸载荷下的动态断裂行为进行了实验分析。实验结果表明:在爆炸载荷下,当炮孔切槽方向与层理面存在一定夹角θ时,爆炸使层理岩体裂纹扩展分为爆生主裂纹、界面裂纹、次生裂纹三个阶段;爆生主裂纹扩展到层理面后,不是直接贯通层理面沿原方向继续扩展,而是产生界面裂纹之后再继续扩展,产生的界面裂纹长度随夹角θ增大而减小;裂纹扩展贯通层理后,次生裂纹继续扩展,随夹角θ的增大,次生裂纹扩展长度逐渐增大;爆生主裂纹扩展过程中,随着爆生主裂纹尖端至层理面距离的减小,爆生主裂纹尖端动态应力强度因子和裂纹扩展速度均逐渐减小,说明层理面对爆生主裂纹的扩展起阻碍作用,且夹角θ越大阻碍作用越明显。实验研究分析了不同角度层理构造缺陷对裂纹扩展规律的影响。
[Abstract]:In order to study the interaction mechanism between explosive crack and bedding defect, a new digital laser dynamic caustic line experimental method is used to analyze the dynamic fracture behavior of layered rock mass under explosive load. The experimental results show that under the explosion load, when there is a certain angle between the cutting direction of the hole and the bedding surface, the crack propagation of the bedding rock mass can be divided into three stages: the main crack, the interface crack and the secondary crack. After the burst main crack propagates to the bedding surface, it does not continue to propagate along the original direction, but the interface crack continues to propagate after the interface crack occurs, and the length of the interface crack decreases with the increase of the angle theta. After the crack propagates through the bedding, the secondary crack continues to propagate, and with the increase of the angle theta, the secondary crack propagation length increases gradually. In the process of burst main crack propagation, with the decrease of the distance from the detonation main crack tip to the bedding surface, the dynamic stress intensity factor and crack propagation velocity at the detonation main crack tip decrease gradually, which indicates that the bedding plays an important role in hindering the propagation of the detonation main crack, and the larger the angle theta, the more obvious the hindering effect. The influence of bedding structural defects at different angles on crack propagation is studied and analyzed experimentally.
【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) 中央高校基本科研业务费资助(2009QL15)
【分类号】：O346.1

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