朱昌星, 刘旭,等.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）,2026,45(1):95-102.

ZHU C X, LIU X,et al.Study on the bearing characteristics of variable-section anchor bolts under pullout loads[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(1):95-102.

拉拔荷载下变截面锚杆承载特性研究

朱昌星, 刘旭

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，提出一种尾部空心的变截面锚杆，开展拉拔荷载下变截面锚杆承载特性研究。 方法 采用理论分析研究拉拔荷载下变截面锚杆锚固段内力分布规律、破坏模式和弹性承载力，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验证理论成果。 结果 结果发现：与普通锚杆相比，空心段引起锚杆轴力分布曲线非线性增加和锚固剂-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2种破坏模式为锚固剂-围岩界面滑脱和变截面位置锚杆破断，根据二者发生条件推导出相应的弹性承载力计算公式和破坏模式临界状态方程，对比2种破坏模式下锚杆弹性承载力和安全性的基础上，确立以锚固剂-围岩界面滑脱为首要破坏模式；当变截面锚杆发生锚固剂-围岩界面滑脱破坏时，其弹性承载力随着空心段尺寸参数增大，初始阶段先缓慢下降，随后加速下降，呈现负指数衰减。 结论 该研究结果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借鉴。

关键词:变截面锚杆;承载特性;破坏模式;弹性承载力

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:2023/12/25

出版日期:2025-12-03

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

Zhu Changxing, Liu Xu

School of Civil Engineering， Henan Polytechnic University， Jiaozuo 454000， Henan， China

Abstract: Objectives To address the problem that the pullout resistance of the steel at the tail of resin anchor bolts in coal mine roadways cannot be fully utilized， a variable-section anchor bolt with a hollow tail is proposed， and its load-bearing characteristics under pullout loads are investigated. Methods Theoretical analysis was employed to examine the internal force distribution， failure modes， and elastic bearing capacity of the anchorage segment of the variable-section anchor bolt under pullout loads. This revealed the influence of the hollow section on the bolt's bearing performance. The theoretical findings were validated through laboratory pullout tests Results Compared to conventional bolts， the hollow section causes a nonlinear increase in the axial force distribution of the bolt and an increase in the maximum shear stress at the resin-rock interface. The magnitude of these changes grows with the size of the hollow section. Two failure modes are identified for the variable-section anchor bolt： debonding at the resin-rock interface and bolt fracture at the variable-section. Based on their occurrence conditions， formulas for calculating the elastic bearing capacity and the critical state equation for each failure mode were derived. By comparing the elastic bearing capacity and safety under the two failure modes， debonding at the resin-rock interface is established as the primary failure mode. When this debonding occurs，  the elastic bearing capacity of the variable-section anchor bolt decreases with increasing hollow section size： initially it declines gradually， then accelerates， showing a negative exponential decay pattern. Conclusions These findings provide theoretical guidance for improving the economic efficiency of coal roadway support systems and addressing the low steel utilization problem in conventional anchor bolts.

Key words:variable-section anchor bolts;bearing characteristics;failure mode;elastic bearing capacity