摘要
为研究深部工程开采过程中开挖速率对岩爆破坏特征的影响,首先,利用自主研发的真三轴应变岩爆实验系统,开展不同卸载速率下的花岗岩应变岩爆实验,借助动态高速应力监测系统和双目高速摄影系统监测试样岩爆过程;其次,分析了卸载速率对试样的岩爆破坏峰值强度、岩爆破坏过程、试样破坏形态以及碎屑块度特征的影响;再次,利用三维激光扫描系统建立了中粗粒碎屑的三维数字模型,分析碎屑三维形貌的几何及表面幅度特征参数;最后,基于分形理论和立方体覆盖法,定量研究了不同卸载速率对岩爆碎屑表面形貌的影响。研究结果表明:随着卸载速率提高,试样岩爆时的峰值强度和破坏烈度增大,岩爆碎屑的破碎程度降低,岩爆破坏模式由张拉型破坏过渡到剪切型破坏。在高卸载速率的影响下,试样内部裂纹未充分发育和扩展,容易形成几何形态规则的岩爆碎屑,并且碎屑表面形貌的复杂程度降低。岩爆碎屑表面形貌具有明显的分形特征,卸载速率越大,碎屑表面形貌的分形维数越小。
To study the effect of excavation speed on rock burst damage characteristic during the mining process of deep engineering,firstly,a series of strainburst experiments under different unloading rates were conducted on granite by using the self-developed true triaxial strainburst experimental system.The rock burst process of specimen was monitored with the dynamic high-speed stress monitoring system and binocular high-speed photography system.Secondly,the influence of unloading rate on peak strength of rock burst damage,rock burst damage process,damage morphology and fragmentation characteristic of specimen were analyzed.Thirdly,the three-dimensional digital model of medium-coarse grained fragment was established by using the three-dimensional laser scanning system,and the characteristic parameters of geometry and surface amplitude for three-dimensional morphology of fragment were studied.Finally,based on fractal theory and cube-covering method,the influence of unloading rate on surface morphology complexity of rock burst fragment was quantitatively studied.The results show that with the increase of unloading rate,the peak strength and damage intensity of specimen during rock burst increase,and the degree of fragmentation of rock burst fragments decreases,meanwhile the damage mode of rock burst transforms from tensile damage to shear damage.The cracks within the specimen are not sufficiently developed and penetrated under the influence of high unloading rate,which will make the geometrical morphology more regular and reduce the complexity of surface morphology of fragment.The surface morphology of rock burst fragment also exhibits distinct fractal characteristic.The higher the unloading rate is,the smaller the fractal dimension of surface morphology of rock burst fragment is.
作者
李春晓
李德建
刘校麟
祁浩
王德臣
LI Chunxiao;LI Dejian;LIU Xiaolin;QI Hao;WANG Dechen(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Mechanic and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第6期2298-2311,共14页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(41572334)
中央高校基本科研业务费专项资金资助(2022YJSSB05)
深部岩土力学与地下工程国家重点实验室(北京)创新基金资助(SKLGDUEK202222)。
关键词
应变岩爆
卸载速率
破坏特征
碎屑形貌
三维激光扫描
分形
strainburst
unloading rate
damage characteristic
fragment morphology
three-dimensional laser scanning
fractal
作者简介
通信作者:李德建,博士,教授,从事深部岩体力学与工程灾害控制研究,E-mail:ldjcumtb@163.com。
