摘要
为探究裂隙倾角及长度对岩石强度和破坏特征影响,应用离散元数值分析软件PFC2D对含不同倾角及长度的单裂隙岩石试件在单轴压缩下的力学特性及裂纹扩展规律进行研究。结果表明:裂隙倾角及长度的不同对岩石力学特性和破坏形态影响较大;线弹性阶段,弹性模量基本一致,线弹性阶段结束后,弹性模量降幅增大,达到峰值强度前,随着岩石试件裂隙长度的增大,应力-应变曲线间距变大,峰值强度后,峰值强度越大的试件其应力降幅越大;裂隙长度相同时,裂隙倾角越大,峰值强度越大;裂隙倾角相同时,裂隙长度越大,岩石试件峰值强度越小,随着裂隙长度的增大,裂隙倾角越小的岩石试件峰值强度降幅越大;起裂裂纹主要从裂隙尖端处起裂并向试件角点和边缘扩展,随着裂隙倾角和长度的增大,破坏形态由剪切型破坏转为剪切张拉复合型破坏。裂隙倾角及长度均会对岩石强度和破坏特征产生影响。
The discrete element numerical analysis software PFC2Dwas applied to study the mechanical properties and crack expansion patterns of single fracture rock specimens with different inclination angles and lengths under uniaxial compression. The results show that: the different fissure dip angle and length have greater influence on the mechanical properties and damage morphology of rocks;the elastic modulus is basically the same in the linear elastic stage, and the drop in elastic modulus increases at the end of the linear elastic stage;before reaching the peak strength, the stress-strain curve spacing becomes larger as the fissure length of the rock specimen increases, and after the peak strength, the larger the peak strength of the specimen, the larger the stress drop;when the fissure length is the same, the larger the fissure dip angle is, the larger the peak strength of the rock specimen.When the fracture length is the same, the larger the fracture dip angle is, the higher the peak strength is;when the fracture dip angle is the same, the larger the fracture length is, the lower the peak strength of the rock specimen is, and as the fracture length increases, the smaller the fracture dip angle is, the higher the peak strength drop of the rock specimen is;the crack initiation mainly starts from the fracture tip and expands to the corner and edge of the specimen, and as the fracture dip angle and length increase, the damage form changes from shear damage to shear-tension compound damage. The damage pattern changes from shear damage to shear-tension compound damage as the slope and length of the fracture increase. Both fracture dip and length have an effect on the strength and damage characteristics of the rock.
作者
张岩
经纬
经来旺
金仁才
程攀
ZHANG Yan;JING Wei;JING Laiwang;JIN Rencai;CHENG Pan(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China;State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,China;Postdoctoral Research Workstation in Civil Engineering,China MCC17 Group Co.,Ltd.,Maanshan 243000,China;Postdoctoral Research Mobile Station,Anhui University of Science and Technology,Huainan 232001,China;School of Mechanics and Optoelectronic Physics,Anhui University of Science and Technology,Huainan 232001,China)
出处
《煤炭技术》
CAS
北大核心
2023年第10期106-109,共4页
Coal Technology
基金
安徽省教育厅高校自然科学研究重大项目(KJ2021ZD0053)
国家自然科学基金资助项目(51904012)
深部煤矿采动响应与灾害防控国家重点实验室开放基金(SKLMRDPC19KF02)
华能庆阳煤电有限责任公司宁正煤田大埋深超厚煤层沿空跟底掘进巷道关键支护技术研究项目(HNQMHTY-051-2022-JZ01)
大柳煤矿有限公司“三软”煤层回采巷道支护技术研究科技项目(HNMYKJ19-04)
安徽省博士后研究人员科研活动经费资助项目(2022B640)。
关键词
数值模拟
裂隙长度
裂隙角度
单轴压缩
峰值强度
裂纹扩展
numerical simulationfracture length
fracture inclination
uniaxial compression
peak intensity
crack propagation
