预应力锚索自由段剪切破坏机制研究  

Research on shear failure mechanism of free section of prestressed anchor cables

作　　者：冯超 刘少伟[1,3] 付孟雄[1] 吕谦 贺德印 何亚飞 FENG Chao;LIU Shaowei;FU Mengxiong;LYU Qian;HE Deyin;HE Yafei(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454000,China;School of Architecture and Civil Engineering,Anyang Institute of Technology,Anyang,Henan 455000,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Henan Polytechnic University,Jiaozuo,Henan 454000,China)

机构地区：[1]河南理工大学能源科学与工程学院,河南焦作454000 [2]安阳工学院土木与建筑工程学院,河南安阳455000 [3]河南理工大学煤炭安全生产与清洁高效利用省部共建协同创新中心,河南焦作454000

出　　处：《岩石力学与工程学报》2024年第6期1468-1479,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52074102);河南省科技攻关计划重点项目(232102321009);安阳市科技攻关项目(2023C01SF207)。

摘　　要：端部锚固型锚索作为一种高效且经济的加固手段,在岩体支护领域应用广泛。端锚锚索自由段剪切破坏是工程实践中常见的一种锚索破坏类型,其破坏机制与全长锚固型锚索有着本质差别,需要进一步深入研究。综合采用实验室试验、理论分析和数值模拟等研究方法,明晰了锚索自由段剪切破坏特征,揭示了预应力锚索自由段板剪切破坏力学机制和细观演化规律。研究结果表明:节理面剪切作用引起锚索内形成耦合增长的轴力和剪力,钢绞线断口同时存在拉伸和剪切破坏2种类型;反弯点处锚索轴力和剪力呈正相关关系,基于拉剪复合破坏准则,较好地解释了锚索剪切破坏力学机制;锚索剪切过程中同时存在拉应力集中区和拉剪复合应力集中区,锚索外缘钢绞线表面剪切损伤导致其较早破坏,锚索内力演化规律证实了锚索剪切破坏属于拉剪复合破坏。研究结果为锚索支护技术的发展提供一定的参考作用。End-anchored prestressed anchor cables,as an effective and economical reinforcement method,are widely used in rock support applications.Shear failure for the free section of end-anchored anchor cables is a common failure type of anchor cables in engineering practice.Its failure mechanism differs from that of full length anchoring cables,which requires further in-depth research.By using the research methods of laboratory test,theoretical analysis and numerical simulation,the characteristics of shear failure in the free section of anchor cables were clarified,and the mechanical mechanism and micro-evolution laws of shear failure in prestressed anchor cables were revealed.The study showed that the shear action on joint surfaces caused coupled growth of axial and shear forces inside the anchor cable,and the steel strands at the fracture exhibited both tensile and shear failure modes.The axial force and shear force in the anchor cable at the inflection point were positively correlated.Based on the combined tensileshear failure criterion,the mechanism of shear failure in anchor cables was well explained.During the shear process,there were both tensile stress concentration area and tensile-shear composite stress concentration area.Shear damage on the surface of the outer steel strands of the anchor cable resulted in earlier failure,and the evolution law of internal forces in the anchor cable confirms that shear failure in the anchor cable was a combination of tension and shear failure.The research results provide a reference for the development of anchor cable support technology.

关 键 词：岩石力学 岩体支护 剪切破坏 锚索自由段 力学模型 数值模拟 

分 类 号：TU45[建筑科学—岩土工程]