鄂西炭质页岩动态拉伸力学特性试验研究  

Experimental Study on Dynamic Tensile Mechanical Properties of Carbonaceous Shale in Western Hubei

作　　者：张湘平[1,2] ZHANG Xiang-ping(China Railway 18th Bureau Group Co.,Ltd.,Tianjin 300222,China;Tianjin University,Tianjin 300192,China)

机构地区：[1]中铁十八局集团有限公司,天津300222 [2]天津大学,天津300192

出　　处：《爆破》2023年第4期52-59,共8页Blasting

基　　金：湖北省自然科学基金(2020CFB428);湖北省重点研发计划项目(2021BAD004)。

摘　　要：为探索湖北省西部地区郑万高铁湖北段苏家岩隧道炭质页岩段围岩动态拉伸力学特性,从而为层状岩体地层隧道爆破破岩机理研究提供依据,采用分离式霍普金森压杆(SHPB)装置,同时借助高速摄像及数字图像相关技术(DIC),开展0°、30°、45°、60°和90°共5种不同冲击角度(冲击加载方向与试样层理面夹角)下鄂西炭质页岩动态巴西劈裂试验,每个冲击角度工况采用0.1 MPa、0.2 MPa及0.3 MPa共3种冲击气压进行动态加载来达到不同冲击速率,以研究冲击角度和冲击速度对炭质页岩动态抗拉强度及动态拉伸破坏模式的影响规律。研究结果表明:不同冲击速度下,随着冲击角度增加炭质页岩动态抗拉强度整体呈现出先减小后增大的趋势,且冲击角度为30°时最小,冲击角度为90°时最大,页岩动态抗拉强度呈现出显著的各向异性特征,且随着冲击速度增加页岩动态抗拉强度各向异性程度也随之降低;随着冲击速度增加,炭质页岩动态抗拉强度均相应增大,且动态抗拉强度与冲击速度具有显著的线性关系;此外,冲击角度和冲击速度均对页岩动态拉伸破坏模式有较大的影响。In order to better study rock blasting mechanism better in layered rock strata,the dynamic tensile mechanical characteristics of the carboniferous shale surrounding rock mass around the Sujiayan tunnel were explored,which belongs to the north section of the Zhengwan high-speed railway project in western Hubei Province.To reveal the effects of impact angle and velocity on the dynamic tensile strength and corresponding failure mode of carbonaceous shale,dynamic Brazilian splitting tests were carried out under five impact angles(0°,30°,45°,60°and 90°)by the split Hopkinson pressure bar(SHPB)device with a high-speed camera and the digital image correlation technology(DIC).At the same time,different impact velocities for every impact angle were also tested by three impact pressures(0.1 MPa,0.2 MPa and 0.3 MPa).The results show that the dynamic tensile strength of the shale decreases first and then increases with the increase of impact angle under different impact velocities.The minimum value is reached when the impact angle is 30°and the maximum value is reached when the impact angle is 90°.The dynamic tensile strength of shale presents a significant anisotropy,and the degree of anisotropy decreases with the increase of impact velocity.With the increase of impact velocity,the dynamic tensile strength of shale increases correspondingly,and there is a significant linear relationship between the dynamic tensile strength and impact velocity.In addition,both impact angle and impact velocity have a great influence on the dynamic tensile failure mode of shale.

关 键 词：炭质页岩 霍普金森压杆 动态巴西劈裂 动态抗拉强度 动态拉伸破坏模式 

分 类 号：TD235.1[矿业工程—矿井建设]