Study on failure characteristics of intermittent jointed rock mass under loading and unloading condition

被引：0

作者：

Zhao Y. ^{[1
,2
]}

Liu J. ^{[1
,2
]}

Jin A. ^{[1
,2
]}

Sun H. ^{[1
,2
]}

Wang B. ^{[1
,2
]}

Wei Y. ^{[1
,2
,3
]}

机构：

[1] School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing

[2] Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mine, University of Science and Technology Beijing, Beijing

[3] State Key Laboratory of Water Resources Protection and Utilization in Coal Mining, Beijing

来源：

Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | 2020年 / 51卷 / 07期

基金：

中国国家自然科学基金;

关键词：

Intermittent jointed rock; Mechanics characteristic; Numerical simulation; Unloading rock mass;

D O I：

10.11817/j.issn.1672-7207.2020.07.015

中图分类号：

学科分类号：

摘要：

The particle flow software PFC(particle flow code) was used to study the failure characteristics of intermittent jointed rock mass under loading and unloading conditions. The indoor uniaxial compression test of sandstone was carried out. The macroscopic characteristics such as compressive strength and elastic modulus of the rock sample were obtained. Using the parallel bonded model in PFC, a complete rock model was constructed and the DFN(discrete fracture network) was adopted to create intermittent joints. The model was used to carry out triaxial compression and nonlinear loading axial pressure-unloading confining pressure simulation using the stress/time step loading-unloading method which was more in line with the actual project. The results show that in the triaxial compression simulation, the peak stress decreases mainly due to the increase of shear cracks in the rock bridge, and the crack extension occurs first in the upper part of the rock bridge, which then leads to the penetration of the rock bridge. In the simulation of nonlinear loading axial pressure-unloading confining pressure, when the axial stress reaches the peak value, the rock bridge breaks slowly. The distribution of tensile crack and shear crack is uniform. After the rock bridge is connected, the crack expands to the upper part. The final failure form is the slip deformation of the upper and lower parts of the non-penetrating joint and the degree of damage of the joint is much larger than theat of the triaxial compression. During the unloading process, the shear stress on both sides of the joint is the largest, the center of the rock bridge is the second, and the shear stress of the joint surface is the smallest. © 2020, Central South University Press. All right reserved.

引用

页码：1893 / 1901

页数：8

共 19 条

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