不同边界约束对锚杆锚固段承载特征的影响  

Influence of different boundary constraints on bearing characteristics of anchorage section of bolt

作　　者：李怀珍[1] 贺炫 LI Huaizhen;HE Xuan(College of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,China)

机构地区：[1]河南理工大学安全科学与工程学院,河南焦作454000

出　　处：《煤矿安全》2022年第6期204-211,共8页Safety in Coal Mines

基　　金：河南省科技攻关资助项目(202102210230);河南理工大学青年探索基金资助项目(NSFRF210306);河南理工大学博士基金资助项目(B2020-5)。

摘　　要：为研究不同边界约束对锚杆锚固段承载特征的影响,在锚杆张拉预紧、锚杆-围岩协调变形承载状态受力分析基础上,采用数值计算方法开展相关研究。结果表明:不同边界约束锚杆轴力沿锚固长度均呈递减分布,有侧向约束锚杆轴力衰减速度较快;顶端固定侧向约束锚杆轴力在锚固长度1/2处递减明显变缓且接近0;底端固定侧向约束锚杆轴力在锚固始端5 cm内递减缓慢,随后呈幂函数递减;顶端固定侧向约束锚杆-锚固剂界面剪应力在锚固外端2 cm处出现峰值,但底端固定侧向约束剪应力峰值位于锚深9~10 cm处;顶端固定侧向约束锚固剂-围岩界面剪应力峰值位于锚固外端口,而底端固定侧向约束时剪应力峰值位于锚深8 cm处;不同边界约束两界面剪应力峰值大小和位置不同,是影响锚固失效模式的重要影响因素。In order to study the influence of different boundary constraints on the bearing characteristics of the bolt anchorage section,the stress conditions of the bolt in the state of tension bearing and bolt-surrounding rock coordinated deformation bearing state were analyzed,and the numerical calculation with different boundary constraints was carried out.The research results show that the axial force of the bolt decreases along the anchorage length under different boundary constraints,and the attenuation speed is faster under lateral constraints.Under the condition of top fixed and lateral restraint,the axial force of the bolt decreases at 1/2 of the anchorage length,obviously slows down and approaches to zero.The axial force of the bottom fixed lateral restraint bolt decreases slowly within 5 cm of the anchorage beginning,and then decreases in a power function.Under the condition of top fixed and lateral restraint,the shear stress peak of the bolt-anchorage agent interface appears at 2 cm of the outer end of the anchorage,while under the condition of bottom fixed and lateral restraint,the shear stress peak is at 9-10 cm of the anchorage depth.Under the condition of top fixed and lateral restraint,the peak shear stress of anchorage agent-surrounding rock interface is located at the outer end of anchorage,and the peak shear stress under the condition of bottom fixed lateral restraint is located at 8cm outside the anchorage.The magnitude and location of the shear stress peak value of the two interfaces are different,which is the important influencing factor of various anchorage failure modes.

关 键 词：煤巷锚杆 锚固段 承载特征 边界约束 数值计算 

分 类 号：TD353.6[矿业工程—矿井建设]