火成岩微波面照射损伤破裂机理研究

微波面照射辅助破岩技术是提高机械破碎火成岩效率、降低刀具磨损的手段之一，关键科学问题是微波致裂火成岩的损伤破裂表征和基于岩石参数的损伤模型的建立。项目采用可控微波功率密度面照射常见火成岩，利用声发射监测、三维形貌扫描、光学相机、便携式显微镜、示踪探伤技术、三维裂纹重构等精细化表征裂纹，利用超声波波速、施密特回弹值衰减、裂纹密度和抗压强度衰减等精细化表征损伤；测定岩石的物理、力学、矿物和介电参数，分析各参数对损伤的显著性，并回归建立多参数微波致裂损伤模型；分析照射点距离和自由边界对裂纹起裂和分布特征的影响，确认最优的微波照射点间距和自由边界距离，揭示微波面照射致裂常见火成岩的机理。项目研究成果有望推动微波致裂岩石技术的理论发展，并为工程应用提供技术支撑，可用于采矿工程、隧道工程、城市地下空间工程、岩石边坡和基础工程中的非爆破岩石开挖，有着重要的应用价值和战略意义。

Microwave assisted breakage of igneous rocks by surface radiation is one of most promising technologies to improve the efficiency of rock cutting machineries and to reduce the cutter wear. The key problem when utilising the technology is to characterise the damage and failure of igneous rocks exposed to surface microwave radiation and to establish a multi-variable damage model based on rock parameters. In this project, surface microwave radiation with a controlled power intensity is to be performed on commonly found igneous rocks. Techniques including acoustic emission measurement, profile scanning, microscope observation and crack extraction, ultrasonic wave velocity tester, Schmidt hammer, and reconstruction of cracks will be used to characterise microwave induced cracks and damage. Meanwhile, physical, mineralogical, mechanical and dielectric properties of the rocks will be measured and the significance of the properties to damage will be investigated. The study then will establish a multi-variable damage model using the entropy weight method. At the end, the optimal radiation spacing and the effect of free boundaries to microwave fracturing will be studied. The rock fracturing mechanisms of surface microwave radiation is then to be revealed. The findings of the project can be used in non-explosion rock excavation in mining engineering, tunnelling, underground space utilisation and rock slope and foundations.