摘要
为探索鄂西页岩地层隧道围岩动态压缩力学特性,采用分离式霍普金森压杆装置(SHPB),同时借助高速摄像,开展0°、30°、45°、60°和90°共5种不同层理角度(冲击加载方向与试样层理面法线的夹角)页岩试样动态冲击压缩试验,并采用不同的冲击气压进行动态加载,使试样达到不同的应变率,以研究层理角度、冲击气压及应变率对页岩动态压缩力学特性和破坏模式的影响机制。研究结果表明:不同冲击气压及应变率下,页岩动态抗压强度随着层理角度的增加,均近似呈现出“U”型的变化规律,其中层理角度为0°和90°,页岩的抗压强度相对较高,而60°层理角度的页岩抗压强度最小,随着冲击气压和应变率增加,不同层理角度页岩动态抗压强度均增加;页岩试样宏观破坏模式主要分为拉伸破坏、剪切破坏和混合破坏,不同应变率下层理角度为0°和90°试样宏观破坏模式均以拉伸破坏为主,当层理角度为30°时,试样主要宏观破坏模式随着应变率的增大,表现为“剪切破坏-混合破坏-拉伸破坏”这一转变过程,当层理角度为45°和60°时,随着应变率的增大试样的主要宏观破坏模式由剪切破坏演变为混合破坏;不同冲击气压下随着层理角度增加,页岩试样吸能比先增大后减小,在层理角度为60°时吸能比最大,此时试样破坏程度也最大,随着冲击气压和应变率增加,不同层理角度页岩试样的破碎程度均增加,且吸能比逐渐趋于一致。研究结果可为鄂西页岩地层隧道爆破破岩机理的研究以及爆破参数的精细化设计提供理论依据。
The dynamic compression mechanical characteristics of the surrounding rock mass of the shale formation tunnel in western Hubei province need detailed exploration.A Split Hopkinson Pressure Bar(SHPB)and a high-speed camera were employed to conduct impact tests on shale samples at five different bedding angles(the angle between the direction of impact loading and the normal of the bedding planes of the specimen,including 0°,30°,45°,60°,and 90°).Meanwhile,the research team also studied the influence mechanism of bedding angles,impact pressure,and strain rate on the dynamic compression mechanical characteristics and failure mode of shale with different dynamic loading strain rates under different impact pressures.The research results indicate that the dynamic compressive strength of shale has an approximately U-shaped pattern with increasing bedding angles under different impact pressures and strain rates.Among them,the shale with bedding angles of 0°and 90°has relatively higher compressive strength,while the shale with a bedding angle of 60°has the most minor compressive strength.Furthermore,the dynamic compressive strength of shale with different bedding angles increases as the impact pressure and strain rate increase.The macroscopic failure modes of shale are mainly divided into tensile failure,shear failure,and mixed failure.Significantly,the macroscopic failure modes of samples with bedding angles of 0°and 90°under different strain rates are mainly tensile failure.The primary macroscopic failure mode of the sample shows a transition process of shear failure mixed failure tensile failure'as the strain rate increases when the bedding angle is 30°.The primary macroscopic failure mode of the specimen evolves from shear failure to mixed failure as the strain rate increases when the bedding angle is 45°and 60°.The energy absorption ratio of shale samples first increases and then decreases as the bedding angle increases under the same impact pressure.Additionally,the energy absorption ratio and the degree of sample damage are simultaneously maximum as the bedding angle is 60°.The degree of fragmentation of shale samples with different bedding angles increases,and the energy absorption ratio gradually tends to be consistent as the impact pressure and strain rate increase.
作者
王江义
董千
颜晓明
童浩
饶小强
姚颖康
魏东
WANG Jiang-yi;DONG Qian;YAN Xiao-ming;TONG Hao;RAO Xiao-qiang;YAO Ying-kang;WEI Dong(Hubei Communications Investment Construction Group Co.,LTD.,Wuhan 430070,China;State Key Laboratory of Precision Blasting,Jianghan University,Wuhan 430056,China;Hubei(Wuhan)Institute of Explosion Science and Blasting Technology,Jianghan University,Wuhan 430056,China)
出处
《爆破》
CSCD
北大核心
2024年第4期73-83,共11页
Blasting
基金
湖北交投建设集团科研课题(LX01-FW-2023052)
国家自然科学基金(52108368)
中国国家铁路集团科研课题(K2021G024)。
关键词
鄂西页岩
霍普金森压杆
动态压缩
力学特性
破坏模式
shale in western Hubei
split Hopkinson pressure bar
dynamic compression
mechanical properties
failure mode
作者简介
王江义(1980-),男,高级工程师、本科,从事公路交通工程方面的科研和管理工作,(E-mail)2759771510@qq.com;通讯作者:董千(1987-),男,副教授、博士,主要从事隧道与地下工程、岩石爆破理论与技术方面的教学与研究工作,(E-mail)dongqian@jhun.edu.cn。
