刘旭，朱昌星.拉拔荷载下变截面锚杆承载特性研究[J].河南理工大学学报(自然科学版)，doi:10.16186/j.cnki.1673-9787.2023100051

LIU X,ZHU C X．Study on bearing characteristics of variable-section anchor rods under pullout loads[J].Journal of Henan Polytechnic University( Natural Science)，doi:10.16186/j.cnki.1673-9787.2023100051

拉拔荷载下变截面锚杆承载特性研究(网络首发)

刘旭，朱昌星

（河南理工大学 土木工程学院，河南 焦作 454000）

摘要:目的 为了解决煤巷树脂锚杆承载时尾部钢材抗拔性能不能充分发挥的问题，提出了一种尾部空心的变截面锚杆。方法 采用理论分析的方法开展了拉拔荷载下变截面锚杆锚固段内力分布规律、破坏模式及弹性承载力研究，揭示空心段对锚杆承载性能的影响规律，并通过室内拉拔试验检验了理论成果。结果 研究发现：相较普通锚杆，空心段的出现将引起锚杆轴力分布曲线非线性程度增加和锚固剂-围岩界面最大剪应力增大，变化幅度随着空心段尺寸参数增大而增大。变截面锚杆的两种破坏模式为锚固剂-围岩界面滑移脱和变截面位置锚杆破断，根据二者发生条件推导出了相应的弹性承载力计算公式和破坏模式临界状态方程，在对比两种破坏模式下锚杆弹性承载力和安全性的基础上，确立了以锚固剂-围岩界面滑移脱黏为首要破坏模式。当变截面锚杆发生锚固剂-围岩界面滑移脱黏破坏时，其弹性承载力随着空心段尺寸参数增大在初始阶段先缓慢下降，随后加速下降，呈现负指数衰减。结论 该研究可为提高煤巷支护系统的经济效益和解决传统锚杆钢材利用率较低的问题提供一定借鉴。

关键词:变截面锚杆；承载特性；破坏模式；弹性承载力

中图分类号:TD353

doi:10.16186/j.cnki.1673-9787.2023100051

基金项目: 国家自然科学基金资助项目（51874119）；河南省教育厅基金资助项目（2011A440003）；河南理工大学博士基金资助项目（B2009-96）

收稿日期：2023/10/23

修回日期：2023/12/22

网络首发日期：2024/01/09

Study on bearing characteristics of variable-section anchor rods under pullout loads

LIU Xu,ZHU Changxing

(School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000,Henan,China)

Abstract:Objective To solve the problem that the pull-out resistance of the tail steel cannot be fully developed when the resin anchor rod is loaded, a hollow variable-section anchor rods at the tail was proposed.Methods Theoretical analysis was used to study the distribution law of internal forces in the anchorage segment, destruction mode, and elastic bearing capacity of variable-section anchor rods under pullout loads. The influence law of hollow segment on the bearing performance of anchor rods was revealed, and the theoretical results were verified through indoor pullout tests.Ｒesults Research has found that compared to ordinary anchor rods, the appearance of a hollow segment will cause an increase in the nonlinearity of the axial force distribution curve of the anchor rods and an increase in the maximum shear stress at the anchorant-perimeter rock interface. The magnitude of the change increases with the increase of the size parameters of the hollow segment. The two destruction modes of the variable-section anchor rods are slip debonding at the anchorant-perimeter rock interface and anchor rods breakage at variable-section position. Based on the occurrence conditions of the two, the corresponding elastic bearing capacity calculation formula and critical state equation of the destruction mode were derived. On the basis of comparing the elastic bearing capacity and safety of the anchor rods under the two destruction modes, the slip debonding at the anchorant-perimeter rock interface was established as the primary destruction mode. When the variable-section anchor rods occurs slip debonding at the anchorant-perimeter rock interface, its elastic bearing capacity slowly decreases in the initial stage with the increase of the hollow segment size parameters, and then accelerates the decrease, showing a negative exponential decay.Conclusion This researches can provide some reference for improving the economic benefits of coal roadway support systems and solving the problem of low utilization of traditional anchor rods steel.

Key words:variable-section anchor rods; bearing characteristics; destruction mode; elastic bearing capacityt

CLC:TD353

 2023100051-拉拔荷载下变截面锚杆承载特性研究 _首发_.pdf