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| 裂隙几何参数对岩体波速及动态力学性能影响的试验研究 |
| Experimental study on the influence of fracture geometric parameters on wave velocity and dynamic mechanical properties of rock mass |
| 投稿时间：2024-07-18 修订日期：2024-09-06 |
| DOI： |
| 中文关键词: 裂隙几何参数 声波波速 霍普金森压杆 破坏模式 DIC |
| 英文关键词:fracture parameters wave velocity split Hopkinson pressure bar failure mode DIC |
| 基金项目:国家自然科学基金面上项目(52374089)；湖南省教育厅科学研究重点项目(23A0350) |
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| 中文摘要: |
| 为研究裂隙几何参数(长度、角度)对岩石波速及动态力学特性的影响,利用RSM-SY5智能声波检测仪和SHPB装置,对不同角度和长度的预制裂隙砂岩试样进行了波速测试和冲击试验,并借助数字图像相关技术(DIC)分析试样在冲击载荷下的变形过程,揭示了不同角度和长度裂隙试样的波速变化规律、动态力学特性以及能量耗散规律。研究表明,裂隙角度与试样纵波波速及初始损伤呈指数关系,裂隙长度与试样纵波波速及初始损伤呈线性关系,且不同裂隙试样纵波波速与其动态抗压强度和动态弹性模量有很好的正相关性。裂隙角度和长度的变化对砂岩的动态力学特性有显著影响,随着裂隙角度和长度的增加,动态抗压强度和动态弹性模量减小,峰值应变增大。α=20°~40°时,试样的动态抗压强度显著下降。试样在受到动载后首先在预制裂隙附近产生剪切裂纹,再产生拉伸裂纹,最后发生拉剪复合破坏；试样表面会出现高应变集中区,在峰值应力附近形成应变局部化带,该局部化带多在裂隙结构面产生。砂岩能量反射率和吸收率随着裂隙角度和长度的增加而增大,能量透射率则减小。研究成果能够更好地预测和评估岩石的破坏行为,为工程灾害的防控与治理提供科学依据。 |
| 英文摘要: |
| In order to investigate the influence of fracture parameters (length, angle) on rock wave velocity and dynamic mechanical properties, wave velocity test and impact test were carried out on the RSM-SY5 intelligent acoustic wave detector and a split Hopkinson pressure bar (SHPB) device for sandstone samples with different prefabricated fracture angles and lengths, and the deformation process of the specimen under impact load were analyzed by utilizing digital image correlation technology (DIC). This approach reveals the variations in wave velocity, dynamic mechanical properties, and energy dissipation characteristics of different angle and length fracture specimens. The results show that there is an exponential relationship between fracture angle, initial damage and the longitudinal wave velocity of the sample, a linear relationship between fracture length, initial damage and the longitudinal wave velocity and a positive correlation between the longitudinal wave velocity, dynamic compressive strength and dynamic modulus of elasticity for different fracture parameters. Differing fracture angles and lengths significantly influence the dynamic mechanical characteristics of sandstone. With increasing fracture angle and length, the dynamic compressive strength and dynamic elastic modulus decrease, while peak strain increases. Notably, when α=20°~40°, the dynamic compressive strength of the sample decreases significantly. Upon exposure to dynamic loads, shear cracks first emerge near the prefabricated fractures, followed by tensile fractures, eventually leading to tensile-shear damage. High strain concentration areas are observed on the specimen surface, forming strain localization zones near the peak stress, primarily seen on the fracture face. The proportions of reflected and absorbed energy in sandstone increase as the fracture angle and length increase, whereas the transmitted energy proportion decreases. The research results can better predict and assess the failure behavior of rocks, providing a scientific basis for the prevention, control, and management of engineering disasters. |
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