河南理工大学学报（自然科学版）2025，Vol.44Issue(2)：1-9,9.DOI:10.16186/j.cnki.1673-9787.2023110042
可接长注浆锚杆连接段破坏失效模式及参数优化
Damage failure mode and parameter optimization of the connecting section of extendable grouting bolts
摘要
Abstract
Objectives To address the challenges of large deformation,prolonged deformation periods,and poor anchorage in high-stress soft-rock tunnels,extendable grouting bolts are commonly used as an im-proved support and reinforcement method.Enhancing the strength and deformation capacity of these bolts has become critical for controlling the significant deformation of surrounding rock.Methods To improve the strength of extendable grouting bolts,theoretical analysis and numerical simulations were employed to study the threaded connection characteristics and failure modes of the connecting segments.The effects of different thread types on the mechanical properties of the bolts were analyzed,and the connection strength of commonly used thread types was compared.The influence of connection length,thread pitch,and con-nector outer diameter on the strength and deformation capacity of the bolts was evaluated,leading to the identification of optimal parameter combinations.Results The findings reveal three failure modes for the connecting segments:thread slip failure,connector pull-off failure,and bolt pull-off failure.These modes depend on the thread shear strength and the minimum tensile strength of the bolts and connectors.When the connection length is short,thread slip failure occurs;as the connection length increases,the weak point transitions from the thread cross-section to the bolt thread root,resulting in bolt pull-off failure.In-creasing the thread pitch initially raises the peak load,which reaches a maximum at a pitch of 2.0 mm be-fore declining.Similarly,increasing the connector outer diameter changes the failure mode from connector pull-off failure to thread slip failure,and eventually to bolt pull-off failure,with the connection strength peaking before declining.Conclusions Taking a hollow grouting bolt with an outer diameter of 22 mm and an inner diameter of 12 mm as an example,the optimal tensile strength of the connecting section is achieved when the connection length is 20 mm,the thread pitch is 2.0 mm,and the connector outer dia-meter is 28 mm.Under these conditions,the peak load reaches 118.8 kN,meeting the support require-ments of high-stress soft-rock tunnels.关键词
中空注浆锚杆/锚杆支护/螺纹连接/螺纹螺距Key words
hollow grouting bolt/bolt support/threaded connection/thread pitch分类
矿山工程引用本文复制引用
刘少伟,张玮钰,贺德印..可接长注浆锚杆连接段破坏失效模式及参数优化[J].河南理工大学学报（自然科学版）,2025,44(2):1-9,9.基金项目
国家自然科学基金资助项目(52074102) （52074102）
河南省自然科学杰出青年基金资助项目(212300410006) （212300410006）
河南省高校科技创新团队项目(23IRTSTHN007) （23IRTSTHN007）
