摘要
为探究围压对锚杆锚固性能的影响,借助自主研发的锚杆围压拉拔试验系统,开展不同围压作用下的锚杆拉拔试验。通过试验获取不同围压条件下锚固体的失效模式及锚固界面破坏形态,阐明围压对锚杆载荷-位移特征曲线、峰值锚固力、锚固力峰值点位移及残余锚固力的影响机制,揭示围压对锚杆锚固性能的作用规律。研究表明:围压显著影响锚固体失效模式,无围压或低围压时围岩试样易产生径向开裂破坏,高围压下试样外部无明显破坏但内部锚固剂出现剪切破碎;锚杆峰值锚固力及位移值均与围压呈线性增长关系,其中峰值锚固力增速为4.28 kN/MPa,峰值点位移增速为0.09 mm/MPa;围压对锚杆残余锚固力影响显著,二者近似呈类指数增长关系;锚固体失效残余阶段,锚杆载荷-位移曲线出现显著振荡,振荡周期与杆体肋间距吻合,且低围压下曲线振荡幅度更为明显。该研究成果可为深部高应力巷道支护方案的优化设计提供依据。
To investigate the influence of confining pressure on the anchoring performance of rock bolts,laboratory pull-out tests were conducted on rock bolts under varying confining pressures using a self-developed rock bolt pull-out test system.Based on the test results,the failure modes of anchorage bodies and the failure modes of anchoring interfaces were obtained,and the influence mechanism of con-fining pressure on the load-displacement characteristic curve,peak anchoring force and corresponding displacement,and residual anchoring force of rock bolts were elucidated.Furthermore,the effect of con-fining pressure on the anchoring performance of rock bolts was unveiled.The research indicates that con-fining pressure has a significant impact on the failure mode of rock bolts.Under zero or low confining pressure conditions,radial cracking failure easily occurs in the surrounding rock specimen.In contrast,under high confining pressure conditions,no obvious external failure is observed in the specimen,but the internal grout undergoes shear fracturing.Both the peak anchoring force and the corresponding displacement grow linearly with the rise of confining pressure,with their growth rate being 4.28 kN/MPa and 0.09 mm/MPa,respectively.Confining pressure has a noticeable influence on the residual anchoring force of rock bolts,with a quasi-exponential growth relationship between them.During the residual stage of anchoring body failure,the load-displacement curve of rock bolts oscillates violently,and the oscillation period aligns with the rib spacing of the bolt bodies.Moreover,compared to high confining pressure conditions,the oscillation amplitude of the curve is particularly pronounced under low confining pressure conditions.The research results provide theoretical support for optimizing support systems in deep highstress roadways.
作者
董双勇
高富强
娄金福
王晓卿
卢志国
DONG Shuangyong;GAO Fuqiang;LOU Jinfu;WANG Xiaoqing;LU Zhiguo(CCTEG Coal Mining Research Institute,Beijing 100013,China;State Key Laboratory of Intelligent Coal Mining and Strata Control,Beijing 100013,China)
出处
《采矿与安全工程学报》
北大核心
2025年第4期747-758,共12页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(52274085,52274123)
天地开采设计事业部科技创新基金项目(TDKC-2022-QN-02,TDKC-2022-MS-01)。
关键词
锚杆支护
锚固力
围压
拉拔试验
锚固失效
rock bolt support
anchoring force
confining pressure
pull-out test
anchorage failure
