界面角度对煤充结构体巴西劈裂特征影响的实验和数值模拟
Brazil splitting characteristics of coal-backfilling composite structure with different interface angles: Insights from laboratory experiment andnumerical simulation
史旭东 1冯国瑞 1白锦文 2朱淳 3王善勇 4王凯 1崔博强 1宋诚1
作者信息
- 1. College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China;Key Laboratory of Shanxi Province for Mine Rock Strata Control and Disaster Prevention, Taiyuan University of Technology, Taiyuan 030024, China
- 2. College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China;Key Laboratory of Shanxi Province for Mine Rock Strata Control and Disaster Prevention, Taiyuan University of Technology, Taiyuan 030024, China;State Key Laboratory of Coal Resources in Western China, Xi ' an University of Science and Technology, Xi ' an 710054, China
- 3. School of Earth Sciences and Engineering, Hohai University, Nanjing 210098, China
- 4. Priority Research Centre for Geotechnical Science and Engineering, School of Engineering, The University of Newcastle, Callaghan, NSW 2308, Australia
- 折叠
摘要
煤柱和充填体作为复合结构共同承担覆岩载荷.煤柱和充填体之间的界面失稳会诱发复合结构的整体失稳.本文通过室内巴西劈裂实验研究了不同界面角度煤充结构体的破坏类型,强度−声发射−数字图像相关响应特征.利用颗粒流数值模拟软件研究了试样的微裂纹,接触力分布和位移矢量演化规律.结果表明:不同界面角度煤充结构体共发生了三种类型破坏;随着界面角度增大,试样的破坏类型从类型I转变为类型Ⅰ-Ⅱ,最后转变为类型Ⅲ;不同界面煤充结构体的强度−声发射−DIC特征与破坏类型相对应;随着界面角度的增大,试样内接触力的分布从加载方向向界面法向演化.煤体元件和充填体元件上的裂纹主要为拉伸裂纹,界面上的裂纹为拉伸,剪切或拉剪复合裂纹.
Abstract
The coal-backfilling composite structure jointly bears the overburden stress. The interface between the coal pillar and backfilling body can easily induce splitting failure of composite system. The failure pattern and load−acoustic emission (AE)−digital image correlation (DIC) response of coal-backfilling (CB) composite structures were investigated through Brazilian splitting tests. The mesoscopic force-fracture distribution, azimuth angle of contact force and displacement vector were then obtained from particle flow code (PFC) numerical simulations. The results show that three types of failure patterns are observed for different CB composite specimens during the Brazilian loading process; with an increase of interface angle, the failure shifts firstly from Type I to Type I-Ⅱ pattern, then turns into Type Ⅲ, and finally becomes Type Ⅱ pattern; For the CB composite specimens with different interface angles, the load−AE−DIC response characteristics correspond to the failure patterns; tensile fracture is dominant when the fracture is distributed on coal or backfilling elements. The fracture may be tensile, shear, or combined tensile-shear fracture when the fracture occurs at the interface.
关键词
煤充结构体/界面角度/巴西劈裂加载/劈裂特征Key words
coal-backfilling composite structure/interface angle/Brazil splitting loading/splitting characteristics引用本文复制引用
基金项目
National Natural Science Foundation of China(52174125)
National Natural Science Foundation of China(51925402)
National Natural Science Foundation of China(52004171)
Outstanding Youth Cultivation Project in Shanxi Province,China(202103021222008)
Open Fund of State Key Laboratory of Coal Resources in Western China(SKLCR20-10)
出版年
2023
NETL
NSTL
维普
万方数据