(1. 河南理工大学 能源科学与工程学院，焦作 454003；
2. 江西理工大学 资源与环境工程学院，赣州 341000；
3. 河南理工大学 煤炭安全生产与清洁高效利用省部共建协同创新中心，焦作 454003；
4. 中南大学 资源与安全工程学院，长沙 410083)
摘 要: 为探究热处理后矿岩的动态力学特性及损伤破坏特征，以含铜矽卡岩为研究对象，开展“岩样密度、热处理温度、冲击气压”三因素影响下的动态冲击试验研究。研究结果表明：“三因素”对含铜矽卡岩本构曲线变化趋势的影响不明显，都未改变动态压缩应力-应变曲线先后经历的似直线段、非线性上凸段、类平台段和峰后下降段；但含铜矽卡岩的动态峰值应力、动态变形模量却随热处理温度的升高而减小，随岩样密度的增大而增大；基于生物种群理论定义了可反映热损伤程度的损伤变量，并得出岩样内部损伤先后经历了缓慢增加-快速增加-减速增加-宏观破坏四个阶段；接着，通过捕捉冲击过程中岩样的损伤历程、分析破碎块度的形状及分形维数特征，得出裂纹起裂于岩样入射端，且分形维数的变化规律与破碎岩块块度随热处理温度、岩样密度、冲击气压变化而变化的规律相呼应；最后结合岩样内部破裂面形态及碎块多呈长条状、三棱锥状和粉末状，得出热处理后含铜矽卡岩的破坏模式复杂多变，且以拉伸破坏和压剪破坏为主，以混合型摩擦破坏为辅。基于研究结论，可推测热处理温度、动态扰动都对矿岩的动态强度劣化、损伤破碎程度起促进作用，而岩样密度的增大有利于提升矿岩抗外界冲击荷载的能力，其为深部资源开发利用及围岩状态控制方案的制定提供了理论参考。
关键字: 高温处理；含铜矽卡岩；动态力学特性；损伤破碎特征；分形维数
（1. School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454003, China;
2. School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
3. Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Henan Polytechnic University, Jiaozuo 454003, China;
4. School of Resources and Safety Engineering, Central South University, Changsha 410083, China）
Abstract:To explore the dynamic mechanical characteristics and damage failure behavior of the rock after heat treatment, a dynamic impact study was conducted on copper-bearing skarn under the influence of three factors: density, heat treatment temperature and impact pressure. The results show that the influences of the "three factors" on the trend of the constitutive curves of copper-bearing skarn were not obvious, and cannot change the approximate straight stage, nonlinear upward convex stage, plateau-like stage and post-peak stage of the dynamic compression stress-strain curves. However, the dynamic compressive strength and deformation modulus of copper-bearing skarn decrease with the increase of heat treatment temperature, but increase with the increase of sample density. Based on the biological population theory, the damage variables reflected the thermal damage degree is defined and it is found that the internal damage of rock samples have experienced four stages successively: slow increase-rapid increase-deceleration increase-macroscopic failure. Then, by capturing the damage history of rock sample during the impact process and analyzing the shapes and fractal dimension behaviors of rock fragments, it is found that the cracks initiate from the incident end of rock sample, and the changed rules of fractal dimension corresponded to the variation of the fragmentation with the change of heat treatment temperature, density and impact pressure. Finally, combined with the internal fracture surfaces of rock and the fragments which are mostly shown as long strip, triangular pyramid and powder shape, it could be obtained that the failure modes of copper-bearing skarn after heat treatment are complex and variable, which are mainly tensile and compression-shear failure and supplemented by mixed friction failure. Based on the conclusions, it could be speculated that the heat treatment temperature and dynamic disturbance promote the dynamic strength degradation and damage failure degree of deep ore rocks, and the increase of sample density is beneficial to improve the ability to resist external impact loads, which could provide theoretical references for the exploitation and utilization of deep resources and the formulation of surrounding rock state control scheme.
Key words: high temperature treatment; copper-bearing skarn; dynamic mechanical characteristic; damage-fracture behavior; fractal dimension
