动载下含预制裂纹砂岩的力学特性及破裂过程研究  

A study on mechanical properties and fracture process of sandstone with prefabricated cracks under dynamic loading

作　　者：石浩 张后全[2] 宋雷[2] 李明[2] 黎明镜[1] 林钢 施鑫 龙伟 吴捷豪 SHI Hao;ZHANG Houquan;SONG Lei;LI Ming;LI Mingjing;LIN Gang;SHI Xin;LONG Wei;WU Jiehao(Anhui Key Laboratory of Mining Construction Engineering,School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China;State Key Laboratory for Geomechanics&Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221008,China;China Coal Mine Construction Group Corporation Ltd.,Hefei 230000,China;Ecole Normale Superieure,Paris 75005,France)

机构地区：[1]安徽理工大学土木建筑学院,矿山建设工程安徽省高校重点实验室,安徽淮南232001 [2]中国矿业大学,深部岩土力学与地下工程国家重点实验室,江苏徐州221008 [3]中煤矿山建设集团有限责任公司,合肥230000 [4]巴黎高等师范学院,巴黎75005

出　　处：《振动与冲击》2023年第4期28-38,共11页Journal of Vibration and Shock

基　　金：安徽理工大学校青年基金(QNZD2021-03);安徽理工大学高层次引进人才科研启动基金项目(2021yjrc16);矿山建设工程安徽省高校重点实验室开放课题资助项目(GXZDSYS2022107);国家自然科学基金面上项目(52274145,41974164,52074240,52174090);中央高校基本科研基金项目(2018ZDPY08);安徽省高等学校自然科学研究重点项目(2022AH050807)。

摘　　要：深入研究缺陷岩石的动力特性对保障深部煤矿巷道等地下硐室在掘进爆破、老顶来压等强扰动作用下的长效稳定具有重要意义。该研究基于天然裂纹长度的幂律分布假设,利用颗粒流软件建立了分离式霍普金森压杆试验系统以及含不同数量分布裂纹的砂岩试件模型,研究了在冲击荷载作用下预制分布裂纹数量对砂岩试件强度、破坏等力学特性的影响。结果显示:(1)随预制裂纹数量(number of prefabricated cracks, NPC)的增加,砂岩试件强度近似呈线性减小趋势,而弹性模量降低规律更接近三次方程,并且随着NPC的增加,试件强度、弹性模量的离散性逐渐增大,试件峰后应力的降低过程也更为复杂;(2)随着NPC的增加,试件的AE事件曲线由单峰值、高极值向多峰值、低极值转变;(3)在冲击荷载作用下,试件中新生裂纹沿应力波传播方向渐进分布,由散斑形式逐渐连通扩展为片层状,并且随着NPC的增加,试件的破坏模式由四周破坏形式转变为自左至右的渐弱破坏形式;(4)试件主要沿应力波传播方向发生破裂,并且NPC越少,倾角沿应力波传播方向的新生裂纹占比越大。The in-depth study on the dynamic characteristics of defective rock is of great significance to ensure the long-term stability of underground chambers such as deep coal mine roadway under strong disturbance actions like excavation blasting and main roof pressure. Based on the power-law distribution assumption of natural crack length, the split Hopkinson pressure bar test system and the sandstone specimen model with different number of distributed pre-cracks were established by the Particle Flow Code software. The effects of distributed pre-crack number on the strength and failure of sandstone specimens were studied. Results show that:(1)with the increase of the number of prefabricated cracks(NPC), the strength of the sandstone specimen decreases approximately linearly, while the decreasing law of the elastic modulus is closer to a cubic equation. Moreover, with the increase of NPC, the discreteness of the specimen strength and elastic modulus gradually increase, and the reduction process of the post-peak stress is also more complicated.(2)with the increase of NPC, the AE event curve of the specimen changed from the form of single peak and high extreme value to the form of multi-peak and low extreme value.(3)under the action of impact load, the new cracks gradually distributed along the propagation direction of stress wave, and communicated and expanded from the speckle form to the lamellar form. And with the increase of NPC, the failure mode of the specimen changed from the surrounding failure mode to the weakening failure mode from left to right.(4)the specimens mainly fracture along the propagation direction of the stress wave, and the fewer NPCs, the larger the proportion of new cracks along the propagation direction of the stress wave.

关 键 词：分离式霍普金森压杆颗粒流模拟 幂律分布裂纹 预制裂纹数量(NPC) 砂岩动力特性 

分 类 号：TD853[矿业工程—金属矿开采]