冲击荷载作用下煤矿泥岩能量耗散试验研究  

Experimental study on energy dissipation of mudstone in coal mine under im-pact loading

作　　者：王梦想[1] 汪海波[1] 宗琦[1] WANG Mengxiang;WANG Haibo;ZONG Qi(School of Civil Engineering and Architecture,Anhui University of Science & Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学土木建筑学院

出　　处：《煤炭学报》2019年第6期1716-1725,共10页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51274009,51404010);安徽省高校自然科学研究重大资助项目(KJ2017ZD11)

摘　　要：岩石破裂破碎实质是一个能量吸收与耗散的过程,煤矿岩巷钻爆掘进过程中,既要有足够的爆炸能量使待开挖区岩石破裂破碎和抛掷、形成空腔,又要控制爆炸能量对保留岩体造成的损伤,尤其是冲击荷载作用时强度较低的泥岩的动态响应特性更需要重点研究。以淮南矿区典型巷道泥岩为研究对象,利用直径50 mm分离式Hopkinson试验装置开展不同冲击气压下泥岩动态压缩试验,研究在冲击荷载作用下泥岩的动态力学性能和破裂破碎特征,重点研究动荷载作用下泥岩的能量耗散规律。为了进一步揭示泥岩动态破碎破裂与泥岩构成主要化学成分与细观结构之间的关系,对泥岩的静态物理力学性能进行了测试并进行泥岩的X射线荧光光谱(XRF)和X射线衍射(XRD)测试,确定其主要组分、化学和颗粒成份;同时采用放大1 000倍的电子数码显微镜对泥岩试件表面、断口进行放大观察,从岩石细观结构出发,通过对细观结构变化、物理与力学过程的分析研究了岩石的损伤及其演化。结果表明:泥岩的主要化学成分主要为SiO2,其次为Al2O3,Fe2O3,其力学强度低,物理性能指标差,在冲击荷载作用下,泥岩内部大量空隙缺陷(如空穴,位错,微裂隙等)动力学过程加剧,形成损伤;在应力波的持续作用下,大量的微损伤和微观不均匀处在试件内部进行复杂的演化,在颗粒内部结构、沿颗粒间裂缝和沿晶粒界会产生大量的微裂纹并发展,在构造边界碎片分层、夹杂物中也产生裂纹,泥岩试件最终产生环向断裂破坏和轴向劈裂拉伸破坏;试件吸收能、透射能和反射能均随入射能增加而增加,分别呈线性、对数和二次函数形式增长;试件吸收能可以用单位体积耗能密度、单位质量耗能和吸收阻抗比能表征,三者均随入射能增加呈线性增长,随应变率呈二次函数增长。Rock crushing is essentially a process of energy absorption and dissipation.In the process of drilling and blasting during the excavation of rock roadway in coal mine,not only sufficient energy should be required to cause rock failure and rupture in the excavation zone,but also the damage caused by explosive energy to retained rock mass should be controlled.Especially the dynamic response characteristics of mudstone with lower strength under impact loading need to be studied emphatically.Taking the mudstone of typical roadway in Huainan mining area as the research object,a 50 mm diameter separated Hopkinson test device is used for the impact compression test on mudstone under different impact pressures to study the dynamic mechanical properties of mudstone and the characteristics of fracture and fragmentation of specimens under dynamic loading.The energy dissipation law of mudstone under dynamic loading was emphatically studied.To further reveal the relationship between the dynamic fracturing of mudstone with the main chemical composition and micro-structure of mudstone,the static physical and mechanical properties of mudstone were tested,and the X-ray fluorescence spectroscopy(XRF)and X-ray diffraction(XRD)of mudstone were carried out to determine the main composition,chemical composition and particle composition of mudstone.The surface and fracture of mudstone specimens were magnified and observed with a 1 000-fold magnification electronic digital microscope.Based on the meso-structure of rock,the damage and evolution of rock were studied through the analysis of the changes of meso-structure,physical and mechanical processes.The results show that the main chemical composition of mudstone is mainly SiO2,followed by Al2O3 and Fe2O3,which have low mechanical strength and poor physical properties.The dynamic process of a large number of void defects(such as voids,dislocations,micro-fissures,etc.)in mudstone intensifies and results in damage under impact loading.Under the continuous action of stress wave,a large num

关 键 词：煤矿泥岩 分离式霍普金森压杆 能量耗散 应变率 破碎破裂 

分 类 号：TD315[矿业工程—矿井建设]