节理接触面积比对压缩波传播影响的动光弹实验研究  

Dynamic photoelastic experimental study on the influence of joint contact area ratio on stress wave propagation

作　　者：王思维 李建春 WANG Siwei;LI Jianchun(Engineering Research Center of Safety and Protection of Explosion and Impact of Ministry of Education,Southeast University,Nanjing,Jiangsu 211189,China;Institute of Future Underground Space,Southeast University,Nanjing,Jiangsu 211189,China)

机构地区：[1]东南大学爆炸安全防护教育部工程研究中心,江苏南京211189 [2]东南大学未来地下空间研究院,江苏南京211189

出　　处：《岩石力学与工程学报》2021年第5期939-947,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家杰出青年基金项目(41525009);国家自然科学基金重点项目(41831281);中央高校基本科研业务费专项资金(3205002010A2)。

摘　　要：岩石节理是影响地下工程安全的重要因素之一,并且显著影响应力波的传播。采用分离式霍普金森压杆(SHPB)设备和光弹设备,开展压缩波垂直入射下节理内部应力集中现象以及波传播特性的无损观测研究。为降低加载杆波阻抗,分离式霍普金森压杆(SHPB)设备的入射和透射杆均采用聚碳酸酯材料。首先,基于改进型SHPB设备,对不同接触面积比的平板型聚碳酸酯节理试样进行压缩波加载实验。根据黏弹性波传播理论和能流密度概念,对动光弹实验图像及波传播特性进行研究。最终,得到不同节理接触面积比及不同节理分布情况下,透射波能流密度与节理附近应力集中现象的内在联系。研究结果表明:随着接触面积比的减小,压缩波透射系数随之减小,透射波能流密度增加,节理附近应力集中现象增加;当接触面积比相同时,随着节理分布的离散程度越高,压缩波透射系数呈现增大的趋势,此时,透射波能流密度增加,节理附近应力集中现象减弱;在动态荷载的作用下,节理附近出现应力集中现象,透射波能流密度与节理附近应力集中现象存在密切的相关性。The presence of rock joints significantly affects not only the propagation of stress waves but also the safety of underground engineering. The purpose of this study is to non-destructively observe the stress concentration around the joints and the characteristics of stress wave propagation. The test on specimens consisting of two contacted polycarbonate plates with an artificial joint was carried out using a modified Split Hopkinson Pressure Bar(SHPB) and a photoelastic equipment. In order to reduce the wave impedance of loading bars, the input and output bars of SHPB equipment were made of polycarbonate materials. The dynamic photoelastic experiment figures and propagation characteristics of the stress wave were studied according to the theory of viscoelastic wave propagation and the concept of energy flow density. Then,the relationship between the energy flow density of the transmission wave and the stress concentration near the joints with different contact area ratios and joint distribution forms was analyzed. The test results show that with decreasing the contact area ratio,the stress wave transmission coefficient decreases while the energy flow density of the transmission wave as well as the stress concentration near the joints increases. When the contact area ratio remains constant,the more dispersed the joints,the greater the stress wave transmission coefficient. In this case,the energy flow density of the transmitted wave increases while the stress concentration near the joints attenuates. Under a dynamic load,the stress concentration phenomenon appears near the joints,and the energy flow density of the transmission wave is closely related to the stress concentration near the joints.

关 键 词：岩石力学 节理接触面积比 SHPB 动光弹法 应力波衰减 节理应力集中 

分 类 号：TU45[建筑科学—岩土工程]