各向异性初始地应力软岩中自膨胀锚杆扩体-拉拔试验研究  

Experimental study on expansion-pullout of self-expansion bolt in soft rock with anisotropic initial ground stress

作　　者：刘杰[1,2] 孙荣琪 张研 宋瑞[1,2] 王昊 孙涛 LIU Jie;SUN Rongqi;ZHANG Yan;SONG Rui;WANG Hao;SUN Tao(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area,Ministry of Education,China Tree Gorges University,Yichang 443002,China;Hubei Geological Disaster Prevention and Control Engineering Technology Center,Yichang 443002,China;Guangxi Key Laboratory of Geomechanics and Engineering,Guilin University of Technology,Guilin 541004,China;School of Civil and Architectural Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [2]湖北省地质灾害防治工程技术中心,湖北宜昌443002 [3]桂林理工大学土木与建筑工程学院,广西桂林541004 [4]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004

出　　处：《煤炭学报》2022年第10期3634-3644,共11页Journal of China Coal Society

基　　金：广西岩土力学与工程重点实验室(桂林理工大学)开放基金资助项目(20-Y-KF-02);湖北省自然科学基金一般面上资助项目(2020CFB584)。

摘　　要：研发了一种掺入了较多HCSA型膨胀剂的自膨胀锚杆,可提升锚杆的极限抗拔力。但对于刚度较低、易变形的介质,自膨胀锚杆的锚固力提升主要因素还不确定。为探明自膨胀锚杆在各向异性初始地应力软岩中的抗拔力提升效果,采用3种壁厚的钢管模拟不同径向刚度的围岩,向钢管内部加入不同膨胀剂掺量的自膨胀锚固材料,通过测试锚固结构的径向膨胀应力和变形的演化规律,推导了在各向异性初始地应力中自膨胀锚杆膨胀应力和位移的分布解析式,建立了应力、变形与钢管壁厚、膨胀剂掺量的关系。基于ABAQUS数值模拟方法验证了公式与试验相吻合,并通过拉拔模拟得到了自膨胀锚杆在低刚度岩土体中的膨胀规律和极限抗拔力的提升效果。研究结果表明:①降低钢管壁厚时,不同膨胀剂含量自膨胀锚杆对应的应力-变形的变化趋势高度一致,在膨胀剂含量较大时,降低钢管壁厚,径向膨胀应力仅减小8.6%,但径向变形量却增大117%,说明扩大头效应更明显。②膨胀剂含量为25%的自膨胀锚杆极限抗拔力在不同刚度的围岩中提升幅度相近,但自膨胀锚杆在相对较高的围岩中抗拔力峰前能量增幅明显更大,达到819%。说明摩擦力对自膨胀锚杆锚固性能的影响比扩体效应更优。最后,建立了以软弱围岩强度参数和初始应力等为判据的膨胀剂掺量设计公式,并在某岩质边坡进行了现场试验,试验结果验证了该公式的可行性。A self-expanding anchor rod with more HCSA-type expansion agent has been developed to increase the ultimate pullout resistance of the anchor rod.But for media with low rigidity and easy deformation,the main factors to increase the anchoring force of self-expanding bolts are still uncertain.In order to prove the lifting effect of the self-expanding anchor rod in the anisotropic initial in-situ stress soft rock,three kinds of wall thickness steel pipes are used to simulate surrounding rock with different radial stiffness,and different expansion agent content is added to the inside of the steel pipe.Self-expanding anchoring material,by testing the evolution law of the radial expansion stress and deformation of the anchoring structure,the analytical formula for the expansion stress and displacement of the self-expanding anchor rod in the anisotropic initial ground stress is deduced,and the stress,deformation and steel pipe are established.The relationship between wall thickness and expansion agent content.Based on the ABAQUS numerical simulation method,the formula is verified to be consistent with the experiment,and the expansion law of the self-expanding anchor in the low-rigidity rock and soil body and the improvement effect of the ultimate pull-out resistance are obtained through the pull-out simulation.The research results show that:①When reducing the wall thickness of the steel pipe,the stress-deformation change trend of the self-expanding anchor rod with different expansion agent content is highly consistent.When the content of the expansion agent is large,the steel pipe wall thickness is reduced,and the radial expansion stress is only reduced.8.6%,but the radial deformation increased by 117%,indicating that the enlarged head effect is more obvious.②The ultimate pull-out resistance of self-expanding bolts with an expansion agent content of 25%is similar in the surrounding rock with different stiffness,but the self-expanding bolts have a significantly greater increase in the energy before the peak of the pul

关 键 词：自膨胀锚杆 锚杆极限抗拔力 围岩刚度 初始地应力 膨胀剂掺量设计 软岩 

分 类 号：TD353.6[矿业工程—矿井建设]