输电线路单群锚基础抗拔特征差异的现场足尺试验  

On-site full-scale test research for difference of anti-pull bearing characteristics between single anchor and group anchors foundation of transmission lines

作　　者：张文翔 崔强 邱昊茨 陆洲 奚邦禄 张振华[4] ZHANG Wenxiang;CUI Qiang;QIU Haoci;LU Zhou;XI Banglu;ZHANG Zhenhua(Power China Fujian Electric Power Engineering Co.,Ltd.,Fuzhou Fujian 350003,China;China Electric Power Research Institute,Beijing 102401,China;State Grid Fujian Quanzhou Electric Power Supply Company,Quanzhou Fujian 362000,China;College of Civil Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]中国电建集团福建省电力勘测设计院有限公司,福建福州350003 [2]中国电力科学研究院有限公司,北京102401 [3]国网泉州供电公司,福建泉州362000 [4]合肥工业大学土木与水利工程学院,合肥230009

出　　处：《地质科技通报》2024年第6期114-124,共11页Bulletin of Geological Science and Technology

基　　金：国网福建省电力有限公司科技项目-适用于福建地区输电线路锚杆复合基础研究(521330210078)。

摘　　要：为研究输电线路单锚与群锚基础抗拔承载特征差异,采用理论分析和现场试验相结合的研究方法,首先根据结构特点,从受力与变形2方面分析了单锚与群锚的承载机制;然后以输电线路基础工程中常用的全长黏结型锚杆为研究对象,选取位于福建泉州地区的花岗岩地基作为试验场地,分别开展了3组单锚、4组群锚的现场足尺拉拔试验,采用位移传感器测试基础与地基变形、采用光频域反射光纤传感技术测试锚杆应变,分析得到试验基础的荷载位移曲线以及锚杆界面内力分布;最后对受力过程中2类锚杆基础的变形破坏机制进行对比分析。结果表明:单锚与群锚荷载位移曲线特征存在差异,群锚反映出的塑性变形特征较单锚明显;加载前半段,锚杆体系位移以锚筋拉伸为主,加载后半段,以锚岩界面滑移为主;锚杆截面轴向应力沿深度方向逐渐减小,且最终在2~3 m深度处趋于0;拉拔荷载作用下的单锚破坏模式与基岩饱和单轴抗压强度有关,而群锚的破坏模式与组成的单锚数量有关;工程中建议以群锚基础试验获得锚岩界面黏结强度为设计依据。研究成果可为输电线路岩石锚杆基础的选型与设计提供参考。[Objective]To investigate the differences in anti-pull bearing characteristics between single anchor and group anchors foundations of transmission lines,[Methods]this study employs a combination of theoretical analy-sis and field experiments.First,based on the structural characteristics,the bearing mechanisms of singleand group anchors were analyzed in terms of force and deformation.The full-length bonded anchors,commonly used in trans-mission line projects,were selected as the research object,with the granite ground in Quanzhou selected as the test site.On-site full-scale tests were conducted on three single anchors and four group anchors.Displacement sensors were used to monitor foundation and ground deformation,while optical frequency domain reflectometry(OFDR)re-corded the strain in the anchor rods.The load-displacement curve of the test foundation and the internal force dis-tribution along the anchor interface were obtained.Finally,a comparative analysis of the deformation and failure mechanisms for both anchor types was performed.[Results]The results show that the load-displacement curve of a single anchor differs from that of group anchors,with plastic deformation being more pronounced in group anchors.In the initial stages of testing,anchor system displacement is primarily governed by the tension in the anchor bars,whereas at the end of the test,displacement is more influenced by slippage at the anchor-rock interface.The axial tension stress of the anchor rod decreases gradually with depth,reaching near-zero at depths of 2 to 3 m.The failure mode of a single anchor under tensile load is related to the saturated uniaxial compressive strength of rock,while the failure mode for group anchors is influenced by the number of single anchor.It is recommended that group an-chors foundation tests be used to determine the bond strength at the anchor interface for design purposes in engi-neering applications.[Conclusion]The research findings can provide references for the selection and design of rock anchor foundatio

关 键 词：输电线路 锚杆基础 现场足尺试验 分布式光纤 锚岩黏结强度 拉拔试验 

分 类 号：TM75[电气工程—电力系统及自动化] TU470[建筑科学—结构工程]