摘要
针对南方广泛存在矿山岩体含水层中的砂岩,利用MTS815试验机进行不同围压下三轴压缩试验,利用RMT-150C试验机进行单轴压缩试验,结果表明:(1)单轴压缩条件下,岩样的全应力-应变曲线明显分为4个阶段:孔隙裂隙压密阶段、弹性变形至裂隙发展阶段、非稳定破裂发展阶段、峰后破坏阶段.(2)单轴压缩条件下峰后应力-应变曲线表现出悬崖式下降趋势的特征;三轴压缩条件下无明显的压密阶段,峰后应力-应变曲线表现出由弹脆性向弹塑性转化趋势的特征.(3)随着围压的增大,除泊松比表现出减小的趋势之外,其余力学参数均有增大的趋势,对峰值强度和峰值应变的影响最为显著,峰值应变逐渐增大,岩样的塑性不断增加,表现出延性破坏的特征.(4)单轴压缩条件下岩样主要以X型裂纹的剪切破裂为主,单一斜平面的剪切破裂为辅;三轴压缩条件下岩样主要以单一裂纹的剪切破裂为主.
Aiming at the sandstone in the aquifer of the rock mass in the south,under different confining pressure,the triaxial compression test by using MTS815 test system,the uniaxial compression test is carried out by using the RMT-150 C test machine. Results show that:(1) Under the condition of uniaxial compression,the full stress-strain curve of the rock sample is obviously divided into four stages,i. e. pore fracture compaction stage,elastic deformation to fracture development stage,unsteady fracture development stage,and post-peak failure stage;(2) The post-peak stress-strain curve shows the characteristic of the cliff-type downward trend,and there is no obvious compaction stage under the triaxial compression condition. The post-peak stress-strain curve exhibits a characteristic of the transition from elastic brittleness to elastoplasticity;(3) With the increase of confining pressure,except for the Poisson’s ratio showing a decreasing trend,the other mechanical parameters have an increasing trend,the peak intensity and peak strain have the most significant influence,and the peak strain gradually increases. The plasticity of the rock sample is increasing,showing the characteristics of ductile damage,and(4) Under the condition of uniaxial compression,the rock sample is mainly shear fracture of Xshaped crack,and the shear rupture of single inclined plane is supplemented. Under the condition of triaxial compression,the rock sample is mainly shear cracking of single crack.
作者
刘强
赵延林
唐利明
程建超
李阳
马文豪
Liu Qiang;Zhao Yanlin;Tang Liming;Cheng Jianchao;Li Yang;Ma Wenhao(School of Resources,Environment and Safety Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Work Safety Key Laboratory on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines,Hunan University of Science and Technology,Xiangtan 411201,China)
出处
《矿业工程研究》
2019年第3期60-65,共6页
Mineral Engineering Research
基金
国家自然科学基金资助项目(51774131)
中国矿业大学煤炭资源与安全开采国家重点实验室开放研究基金资助项目(SKLCRSM16KF12)
长江科学院开放研究基金资助项目(CKWV2017508/KY)
关键词
孔道砂岩
围压
三轴压缩
单轴压缩
峰值强度
峰值应变
延性
pore sandstone
confining pressure
triaxial compression
uniaxial compression
peak strength
peak strain
ductility
