摘要
对微波辐射前后的玄武岩试样进行波速测试和单轴抗压试验,结合扫描电镜试验和宏微观裂隙分析探究了微波辐射岩石升温-损伤-致裂的关联性机制。结果表明:在1.4 kW微波作用下试件两端先迅速升温,随后试件中部再缓慢升温,在空间上呈中间低两端高的双峰状分布;微波加热后试件纵波波速随着辐射时间的增加逐渐降低,损伤因子和强度折损系数随着辐射时间增加呈阶段性上升趋势,波速损伤因子拐点区间为160~180 s,强度折损系数拐点区间为160~200 s,“拐点”之后损伤因子进入平台期,不再随辐射时间的增加有较大变化;微波加热导致的试件内与外、上与下的不均匀温度分布,使试件产生了微裂纹,其裂纹扩展可分为3个阶段:起裂阶段(0~160 s)、裂纹扩展阶段(160~240 s)、崩裂破坏阶段(300 s后),在波速损伤因子与强度折减因子陡增的阶段观察到的裂纹扩展最为显著。研究成果可为类似条件下硬岩微波辐射提供参考。
Wave velocity and uniaxial compressive tests were performed on basalt specimens before and after microwave radiation.The correlation mechanism between heating,damage,and cracking in microwave-irradiated rocks was investigated by combining scanning electron microscope tests with macro-and microfracture analysis.The results show that:Under 1.4 kW microwave irradiation,the two ends of the specimen heated up rapidly at first,followed by slower heating in the middle,resulting in a bimodal temperature distribution with higher temperatures at the ends and lower temperatures in the center.After microwave heating,the longitudinal wave velocity of the specimen gradually decreased with increasing radiation time.Both the damage factor and strength loss coefficient increased progressively with radiation time.The inflection point for the damage factor in wave velocity occurred between 160 and 180 seconds,and the inflection point for the strength loss coefficient was between 160 and 200 seconds.After the“inflection point”,the damage factor reached a plateau and no longer exhibited significant changes with continued radiation.The inhomogeneous temperature distribution within the specimen—due to the microwave heating—induced microcracks,and crack expansion occurred in three stages:crack initiation(0~160 s),crack expansion stage(160~240 s),and collapse and damage stage(after 300 s).The most significant crack expansion occurred during the steep increase in both the damage factor of wave velocity and the strength loss coefficient.The findings of this study can provide valuable insights and references for microwave radiation effects on hard rocks under similar conditions.
作者
陈登红
施伟
王智鹏
汪朝家
袁永强
Chen Denghong;Shi Wei;Wang Zhipeng;Wang Chaojia;Yuan Yongqiang(School of Mining Engineering,Anhui University of Science and Technology,Huainan,Auhui 232001,P.R.China;State Key Laboratory for Safe Mining of Deep Coal Resources and Environment Protection,Huainan,Anhui 232001,P.R.China;School of Civil Engineering,Lanzhou University of Science and Technology,Lanzhou 730000,P.R.China)
出处
《地下空间与工程学报》
北大核心
2025年第5期1544-1553,共10页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51974008)
智能采矿工程新建专业质量提升项目(2022xjzlts008)
省级研究生联合培养示范基地(2022lhpysfjd037)
安徽理工大学研究生创新基金(2023CX2036)。
关键词
微波破岩
玄武岩
损伤规律
损伤因子
microwave breaking rock
basalt
damage law
damage factor
