摘要
为分析矿山深部岩石动力学特性及细观裂纹萌生、扩展以及相互贯通的破坏机制,使用改进的霍普金森试验设备,对白云岩进行常规单轴冲击试验,从应力-应变、强度、能量分布方面探讨了矿岩的动态力学性质,并借助高速摄影设备对白云岩试件的冲击破坏形态及模式进行细观描述。试验得到:白云岩试件动态强度随加载应变率从41.5 s-1增大到112.5s-1,动态抗压强度峰值从104.53 MPa提高到208.6 MPa,且强度峰值出现的时间越来越早;单位体积吸收能随应变率提高呈线性增加关系,破碎块体尺寸随单位体积吸收能的增大而减小;高速摄影细观分析显示,冲击应变率越大,试件完全破坏的发生时间越早,破坏越严重,试件主要破裂面的形成方向与冲击方向一致,属于沿轴方向冲击荷载作用下的拉伸破坏。
In order to analyze the rock dynamic characteristics and failure mechanism in the process of generation,propagation and coalescence of cracks,a dynamic impact compression test for dolomite was carried out by using improved split Hopkinson pressure bar apparatus. The dynamic impact characteristics of deep dolomite was obtained. The impact failure morphology and mode of dolomite specimens were described by means of high-speed photographic equipment. The results show that as the load strain rate increased from 41.5 s^（-1） to 112.5 s^（-1）,the peak dynamic compressive strength of dolomite increased from 104.53 MPa to 208.6 MPa,and the intensity peak appeared earlier. The unit volume absorption energy increased linearly with the strain rate,and the size of the broken block decreased with the increasing of unit volume absorption energy. Mesoscopic analysis of high-speed photography showed that the larger the impact strain rate was,the earlier the failure occurred,the more serious the damage was.The failure of the specimens was mainly formed on the fracture surface along the impact direction. There was no interaction between the fracture plane,which was the tensile failure caused by the poisson effect of axial impact.
作者
张智宇
王建国
黄永辉
李祥龙
赵文
Zhang Zhiyu;Wang Jianguo;Huang Yonghui;Li Xianglong;Zhao Wen(Faculty of Land Resources Engineering,Kunming University of Science and Technology,Kunming 650093,P.R.China;College of Civil and Architectural Engineering,Yunnan Agricultural University,Kunming 650201,P.R.China;Faculty of Electric Power Engineering,Kunming University of Science and Technology,Kunming 650500,P.R.China;Guizhou Kaiyuan Blasting Engineering Co.Ltd.,Guiyang 551400,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2018年第5期1195-1201,共7页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51564027)
云南省科技厅基础研究青年项目(2016FD029)
云南省教育厅科学研究基金(2016ZZX108)
