扰动冲击下弱胶结红砂岩的能量耗散与分形特征  

Energy dissipation and fractal characteristics of weakly cemented red sandstone under disturbance impact

作　　者：张慧梅[1] 陈世官 王磊[2] 程树范 杨更社[2] 申艳军 ZHANG Hui-mei;CHEN Shi-guan;WANG Lei;CHENG Shu-fan;YANG Geng-she;SHEN Yan-jun(Department of Mechanics,Xi’an University of Science and Technology,Xi'an 710054,China;College of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;School of Civil and Architectural Engineering,Wuhan University,Wuhan 430072,China;School of Geology and Environment,Xi’an University of Science and Technology,Xi'an 710054,China)

机构地区：[1]西安科技大学力学系,陕西西安710054 [2]西安科技大学建筑与土木工程学院,陕西西安710054 [3]武汉大学土木建筑工程学院,湖北武汉430072 [4]西安科技大学地质与环境学院,陕西西安710054

出　　处：《岩土工程学报》2022年第4期622-631,I0004,I0005,共12页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(12172280,42077274,41907259);陕西省自然科学基金重点项目(2020JZ-53)。

摘　　要：为探索动态扰动后西部矿区软岩夹层的能量耗散规律和破坏模式,利用分离式霍普金森压杆装置对弱胶结红砂岩进行动态冲击破坏试验,分析该类红砂岩在受到不同加载速率、不同次数扰动冲击以及是否扰动的条件下,试样在相同加载速率破坏性冲击过程中的能量耗散与分形特征。试验结果表明:在不同速率扰动冲击作用下,随着扰动冲击次数的增加反射能递增而透射能和耗散能呈减小趋势,其中较高速率扰动冲击下试样的反射能高于低速率扰动冲击,耗散能则相反,且低速率扰动冲击下试样的耗散能、能量耗散率和能量耗散密度高于较高速率扰动冲击,表明低速率扰动冲击下试样的能量利用率更高;在破坏性冲击试验中,随着扰动冲击次数的增加,低速率扰动后试样的破碎程度相较于未扰动与高速率扰动更为严重,对应分形维数D_(b)低速率扰动>未扰动>高速率扰动,表明分形维数与扰动冲击次数呈正相关,与扰动冲击速率呈负相关;在相同扰动冲击次数下,低速率扰动试样的D_(b)所对应累积耗散能和耗散能密度高于较高速率扰动试样,而对应的累积反射能则相反。To explore the energy dissipation law and failure mode of soft rock interlayer in western mining areas of China after dynamic disturbance,the dynamic impact failure tests on weakly cemented red sandstone are carried out by using the separated Hopkinson compression bar device.Under the impact of this red sandstone under different loading rates,different times of disturbance and whether there is the disturbance or not,the energy dissipation and fractal characteristics of the samples during the same loading rate impact failure are analyzed.The experimental results show that under different disturbance impact rates,with the increase of disturbance impact times,the reflection energy increases,while the transmission energy and dissipation energy decrease.The reflection energy of the samples under the impact of high-speed disturbance is higher than that of the low-speed disturbance impact,while the dissipative energy is the opposite.Moreover,the dissipative energy of the samples under the impact of low-speed rate disturbance is opposite.The energy dissipation rate and energy dissipation density are higher than those of the high-speed disturbance impact,which indicates that the energy utilization rate of the samples is higher under the impact of low-speed disturbance.In the impact failure tests,with the increase of the number of disturbance impact,the fragmentation degree of the sample after the low-speed rate disturbance is more serious than that of the undisturbed and high-speed rate disturbance.The low-speed rate disturbance of fractal dimension D_(b)>undisturbed>high-speed rate disturbance shows that the fractal dimension is positively correlated with the number of disturbance shocks.The results show that the impact rate is negatively correlated with the disturbance.Under the same number of disturbance impact,the cumulative dissipation energy and energy density of D_(b) of the low-speed rate-disturbed samples are higher than those of the high-speed disturbed samples,while the cumulative reflection energy is opposite.

关 键 词：弱胶结砂岩 扰动冲击 SHPB 能量耗散 分形维数 

分 类 号：TU458.3[建筑科学—岩土工程]