摘要
为了探究水对砂岩冲击岩爆的弱化机制,开展5组不同含水程度的砂岩冲击岩爆实验。采用声发射以及高速摄影系统对实验全过程进行监测。实验结果表明,不同含水程度下砂岩冲击岩爆均经历了颗粒弹射、碎屑剥落以及全面岩爆这3个过程。随着含水程度的增加,冲击岩爆的剧烈程度逐渐减弱,这体现在声发射累积能量下降,岩爆碎屑的质量减少,碎屑的分形维数降低。此外,从能量角度以及裂纹演化的角度,初步揭示了水弱化冲击岩爆剧烈程度的机制,包括:(1)水增强了砂岩的塑性变形能力,相对弱化了砂岩的储能能力,降低了砂岩的岩爆倾向性,进而起到弱化砂岩冲击岩爆剧烈程度的作用;(2)水降低了砂岩颗粒之间的黏结力,加速了剪切裂纹的扩展,不利于岩爆前砂岩的板裂化行为形成,破坏了岩爆的孕育条件。
To investigate the weakening mechanism of water on impact-induced rockburst,15 experiments were performed considering different water content levels on cubic sandstones.Photography and acoustic emission(AE)system were used to monitor the rockburst process.According to the photography results,impact-induced rockburst under different water content levels all experience three processes:particle ejection,debris peeling,and comprehensive rockburst.In addition,the results also show that the higher the water content level,the lower the intensity of the rockburst.This effect is reflected in the fact that the AE energy,the quality and the fractal dimension of fragment show a decreased trend with the increase in the water content level.Based on the perspective of energy and micro-crack evolution,two mechanisms are proposed to explain the weaking effects of water on rockburst intensity,including:(1)water increases the plastic deformation capacity,weakens the energy storing capacity and reduces the rockburst tendency of sandstone,resulting in a slightly intensity of rockburst,and(2)water accelerates the expansion of shear cracks,which is not conducive to the occurrence of plate cracking before rockburst,and destroys the conditions for rockburst inoculation.
作者
刘冬桥
孙杰
曹冰昊
何满潮
张梓谦
彭栋
LIU Dongqiao;SUN Jie;CAO Binghao;HE Manchao;ZHANG Ziqian;PENG Dong(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Beijing 100083,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第10期2441-2455,共15页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52074299,41941018)
中央高校基本科研业务费专项资金资助项目(2023JCCXSB02)。
关键词
岩石力学
冲击岩爆
水
声发射
裂纹演化
rock mechanics
impact rockburst
water
acoustic emission
crack evolution
