楠竹加筋复合锚杆内部界面黏结滑移模型  

Bond-slip model for bamboo-steel cable composite anchor

作　　者：张虎元[1] 王晓东[1] 王旭东[2] 吕擎峰[1] 张艳军[1] 

机构地区：[1]兰州大学西部灾害与环境力学教育部重点实验室,兰州730000 [2]敦煌研究院,甘肃敦煌736200

出　　处：《岩土力学》2011年第3期789-796,共8页Rock and Soil Mechanics

基　　金：国家科技支撑计划课题资助项目(No.2006BAK30B02);古代壁画保护国家文物局重点科研基地开放课题

摘　　要：楠竹加筋复合锚杆已经应用于中国西北丝绸之路上留存的古代土遗址保护加固工程中。该锚杆截面积大,可以获得足够大的锚固力。针对现场拉拔试验中钢绞线从内黏结剂中拔出的破坏形式,设计了专门的试件及夹具,试验研究了钢绞线与内黏结剂间的力学行为。试验结果表明,钢绞线与内黏结剂的黏结滑移分为指数上升阶段、软化下降阶段和残余应力阶段3个阶段,可以用简化模型和精确模型描述。试验还表明,钢绞线与内黏结剂接触界面上应力分布不均匀,靠近加载端的应力较大,且有应力峰,应力峰随荷载的逐渐增大向远离加载端的方向移动;钢绞线与内黏结剂间平均剪切应力随锚杆的长度增大呈指数衰减。通过理论分析,给出了界面黏结滑移微分方程及相关曲线,结果表明,钢绞线轴力及界面相对滑移沿钢绞线均呈不均匀分布,且随着距加载端的距离增加其值急剧下降,该规律可以指导锚杆设计及工程应用。The bamboo-steel cable composite anchor（BSCC anchor） is a new anchor with phyllostachys heterocyclavar as pipe material,and was applied to reinforce earthen ruins bequeathed on the ancient silk road in Northwest China,which can get high anchorage strength due to its big cross-section.Field test illustrated that the failure of BSCC anchor was characterized by pulling-out of steel strand from inner binder.In order to understand the working mechanism between inner binder and steel strand,laboratory tests were conducted on four species of specimens,to investigate the bond-slip property between them.The test results indicate that there are three stages for the bond-slip process between inner binder and steel strand which are exponential-enhancing stage,softening-declining stage and residual stress stage.Moreover,the length of softening-declining stage is short,and the bond-slip process can be described by a simplified model and an exact model.It is found that the shear stress is not uniform distributing between the interface of inner binder and steel strand;and it approaches a peak near the loading end;and the peak stress increases and shifts far further from the loading end when pulling load is increased.The average shear stress between inner binder and steel strand,submits exponential decay regularity,and decreases along with the anchor length during the bond-slip process.It acquires the differential equation of bond-slip through theory analysis,and the variation rules of the axial force of steel strand and relative displacement between the interface of inner binder and steel strand.From results,it is found that the axial force of steel strand and relative displacement decrease along with the anchor length;and the results can be used for anchor design and application.

关 键 词：楠竹加筋复合锚杆 土遗址 黏结滑移 模型 

分 类 号：TU502.6[建筑科学—建筑技术科学]