摘要
为探究拉伸破坏条件下含片理结构岩石的各向异性,对不同加载角度的黑云母石英片岩开展巴西劈裂试验,并借助声发射技术,进行片岩破坏特征的理论和试验分析.结果表明:片岩的破坏规律为压密变形-弹性变形-瞬时破坏,具有典型的塑-弹性变形特征.依据裂纹形态,可分为中央直线劈裂、沿片理斜劈裂、弓形劈裂及沿片理弓形复杂劈裂4类破坏模式.通过分析加载线上各点的应力状态,不同角度下加载线上的点存在纯剪切、压剪和拉剪3种破坏机制.声发射特征参数各向异性显著,累计能量与角度呈"两边大、中间小"的变化规律.引入新参量"能率峰值比"对能率峰值和累计能量进行联合分析,22.5°岩样的能率峰值比最大,最小值则出现在45°,该参量可从能量角度定量地表征岩石破坏强烈程度.
To study the anisotropy of schist,acoustic emission technology under Brazilian tests had been carried out to investigate failure modes on biotite quartz schists.The results indicate that(1)the process of failure under Brazilian splitting test can be divided into three stages,i.e.compaction deformation,elastic deformation and instantaneous destruction.Test samples have typical plastic-elastic failure characteristics.(2)Failure modes can be divided into four types,i.e.central straight line splitting,chop splitting along schistosity,bow splitting,and complex bow splitting along schistosity.(3)Through analyzing the stress state and failure mechanism of each point on the loading line,the center point is tensile failure and others are shear failure.By the weak surface theory of shear failure,there are three shear failure mechanisms on the loading line under different angles.(4)The AE total energy and angle have obvious trend that it is higher on both sides and lower in the middle.A new parameter which can quantitatively analysis between maximum energy rate and total energy is introduced with the maximum value at angle of 22.5°and the minimum value at angle of 45°.This parameter can quantitatively characterize degrees of failure on energy perspective.
作者
齐群
包含
晏长根
许江波
翟勇
Qi Qun;Bao Han;Yan Changgen;Xu Jiangbo;Zhai Yong(School of Highway,Chang'an Univ.,Xi'an 710064,China)
出处
《三峡大学学报（自然科学版）》
CAS
北大核心
2019年第6期65-70,共6页
Journal of China Three Gorges University：Natural Sciences
基金
国家自然科学基金(41807246,41790443)
陕西省自然科学基础研究计划(2018JQ4017)
中央高校基本科研业务费专项资金(300102219217,300102218412)
关键词
片岩
巴西劈裂试验
声发射
破坏机制
各向异性
schist
Brazilian splitting test
acoustic emission
failure mechanism
anisotropy
