Chen Yian, Zhao Shujie, Xu Jiang, Jiao Feng, Xiao Zhiyuan
College of Safety and Engineering, Anhui University of Science and Technology, Huainan 232001, China.
State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.
ACS Omega. 2024 Aug 7;9(33):35961-35972. doi: 10.1021/acsomega.4c05439. eCollection 2024 Aug 20.
In the construction of underground geological engineering, a variety of rocks were often encountered, and the engineering surrounding rocks was prone to shear fracturing. Shear mechanics tests were conducted on a variety of rocks under various joint angles. By studying the shear mechanical characteristics, acoustic emission behavior, and damage degree of the different rock types, we can obtain an insight into their bearing capacity and fracture mechanisms. An obvious inflection point from the elastic to plastic behavior can be observed for the specimens during the process of shear mechanics tests, and the shear behavior was divided into three phases. The acoustic emission signals significantly increased for coal during the second phase, while those of sandstone and shale start to increase during the third phase, which is from the peak point to fracture. The analyses of the shear failure and acoustic emission properties showed that the crack propagation angle increases as the normal stress of rock increases. It was proved that the joint angles and normal stresses of rock could effectively hinder the development of vertical fractures. Based on the shear failure and acoustic emission properties, a constitutive model capable of describing the shear behavior of different types of rocks was developed. This constitutive model can accurately describe the shear fracture properties of the various rocks. The shear failure properties and damage constitutive model of rocks in this study can be used to reduce engineering surrounding rock instability caused by shear.
在地下地质工程建设中，常常会遇到各种岩石，工程围岩容易发生剪切破裂。在不同节理角度下对各种岩石进行了剪切力学试验。通过研究不同岩石类型的剪切力学特性、声发射行为和损伤程度，可以深入了解它们的承载能力和断裂机制。在剪切力学试验过程中，可以观察到试样从弹性行为到塑性行为有一个明显的拐点，剪切行为分为三个阶段。煤在第二阶段声发射信号显著增加，而砂岩和页岩的声发射信号在第三阶段，即从峰值点到破坏阶段开始增加。对剪切破坏和声发射特性的分析表明，裂纹扩展角随岩石法向应力的增加而增大。结果表明，岩石的节理角度和法向应力能够有效地阻碍垂直裂缝的发展。基于剪切破坏和声发射特性，建立了一个能够描述不同类型岩石剪切行为的本构模型。该本构模型能够准确地描述各种岩石的剪切断裂特性。本研究中岩石的剪切破坏特性和损伤本构模型可用于减少由剪切引起的工程围岩失稳。
