摘要
为了探究锁固岩桥破坏模式及演化机制,通过在完整试样端部预制裂隙以形成中部岩桥,采用物理试验和RFPA^2D数值模拟方法,研究不同锁固岩桥角度试样破坏模式及裂隙扩展演化机制的影响规律,并利用断裂力学理论分析岩桥裂隙扩展机理。研究结果表明:利用数字图像技术,从定量角度分析裂隙扩展类型,得出试验试样最终破坏是由前期损伤不断积累所导致的结果;锁固段岩桥角度α对锁固段的破坏有重要影响,当α≤90°时,锁固岩桥段发生张拉贯通破坏;当90°<α<120°时,锁固岩桥段发生张拉剪切贯通破坏;当α≥120°时,锁固岩桥段并没有发生贯通破坏。最终得出3种试样破坏模式:下部裂隙张拉扩展,贯通中部岩桥;上下部裂隙同时张拉扩展,剪切贯通中部岩桥;下部裂隙张拉扩展,贯通试样上端面,中部岩桥没有发生破坏。
In order to explore the failure mode and evolution mechanism of the locked rock bridge,the central rock bridge was formed by prefabricating the cracks at the end of intact specimen,and the influence of different locked rock bridge angles on the failure mode and crack propagation evolution mechanism of the specimens was studied by means of physical test and RFPA2D numerical simulation,and the crack propagation mechanism of rock bridge was analyzed by using the fracture mechanics theory.The results showed that by using the digital image technology,the types of crack propagation were analyzed quantitatively,and it was concluded that the final failure of the test specimen was caused by the continuous accumulation of damage in the early stage.The rock bridge angleαof the locked section had important influence on the failure of the locked section.Whenα≤90°,the tension penetration failure occurred in the locked rock bridge section.When 90°<α<120°,the tension-shear penetration failure occurred in the locked rock bridge section.Whenα≥120°,there was no penetration failure in the locked rock bridge section.Three failure modes of the specimens were summarized,the first was the tension and expansion of lower crack penetrated the central rock bridge,the second was the simultaneous tension and expansion of lower upper and lower cracks penetrated the central rock bridge with shearing,and the third was the tension and expansion of lower crack penetrated the upper end face of the specimen,without the failure of central rock bridge.
作者
袁新华
YUAN Xinhua(Department of Architectural Engineering,Henan Technology College of Construction,Zhengzhou Henan 450000,China)
出处
《中国安全生产科学技术》
CAS
CSCD
北大核心
2020年第9期116-121,共6页
Journal of Safety Science and Technology
