采矿与安全工程学报 ›› 2016, Vol. 33 ›› Issue (3): 528-534.

• 论文 • 上一篇    下一篇

基于细观特征分析的单节理岩石破裂机理研究

  

  1. 北京科技大学土木与环境工程学院,金属矿山高效开采与安全教育部重点实验室,北京 100083
  • 收稿日期:2015-09-28 出版日期:2016-05-15 发布日期:2016-06-03
  • 作者简介:柴金飞(1989—),男,河北省邯郸市人,博士研究生,从事岩石破裂机理及其演化规律方面的研究。
  • 基金资助:

    科技北京百名领军人才培养工程项目(Z151100000315014);国家自然科学基金项目(51174014);中国博士后科学基金面上项目 (2015M570037);国家青年自然科学基金项目(51504016)

Research on single jointed rock failure mechanism based on mesoscopic characteristics analysis

  • Received:2015-09-28 Online:2016-05-15 Published:2016-06-03

摘要: 为揭示不同节理方位对岩石破裂机理的影响,利用 PFC 软件模拟岩石裂纹孕育、发展和贯通过程中产生的大量声发射数据,基于矩张量理论、P-T 图法和 T-k 图法研究了岩石破裂各阶段中声发射事件的空间位置、破裂方位、破裂类型、应力状态、矩震级等破裂参数及其演变规律。试验结果表明:1) 岩石破裂方位受加载方向和节理方位影响,当节理方位与加载方向呈一定夹角时,主压应力分量逐渐分布在与节理方位对应的 P-T 图位置附近。2) 线性张拉破裂所占比例随节理角度的增大而减小,线性剪切破裂、混合破裂和双力偶剪切破裂所占比例随节理角度的增大而增大。3) 张拉破裂主要分布于节理面上,其矩震级(能量)较小;剪切破裂和混合破裂主要分布于节理面与临空面的交线上,其矩震级较大。运用矩张量理论、P-T 图法和 T-k 图法可有效掌握岩石破裂机理及其宏观演变规律,可为分析岩体稳定性及其发展趋势提供一种新的技术手段,是传统分析方法的有效补充。

关键词: 节理岩石, 声发射, 矩张量, 破裂类型, 破裂方位

Abstract: Based on moment tensor theory, P-T diagram method and T-k diagram method, the fracture parameters and their evolution such as spatial position, fracture azimuth, fracture types, stress state and moment magnitude were analyzed to reveal the rock failure mechanism of triaxial compression under the condition of different confining pressure with a large number of acoustic emission (AE) data in the process of generation, propagation and coalescence of cracks simulated by Particle Flow Code. The results have shown that:1) The rock fracture azimuth is influenced by the loading direction and the joint orientation. When the joint orientation and the loading direction are in a certain angle, the principal compressive stress components are gradually distributed around with the joint orientation corresponding location of the P-T diagram. 2) The proportion of linear tension fracture decreases as the angle between joint and Z-axial increases. The proportion of linear shear fracture, mixed fracture and double couple shear fracture increases as the angle between joint and Z-axial increases. 3) The tensile fracture is mainly distributed in the joint plane, and its energy is lower. The shear fracture and mixed fracture type is mainly distributed in the intersecting line of joint plane and free face; and its energy is higher. In conclusion, the rock fracture mechanism and its macroscopic evolution rule can be effective grasped with the moment tensor theory, P-T diagram method and T-k diagram method. These methods provide a new technical measure for the stability analysis of rock mass and its development trend, which is an effective supplement to the traditional analysis method.

Key words: jointed rock, acoustic emission, moment tensor, fracture type, fracture azimuth