钢花管与预应力锚索组合结构力学响应现场试验  

Field Test of Mechanical Response of Steel Spoil Tube and Prestressed Anchor Cable Combination

作　　者：钟文杰 袁坤 王辉 ZHONG Wenjie;YUAN Kun;WANG Hui(Dachao Expressway Corporation Limited,Meizhou Guangdong 610036,China;Railway Engineering Research Institute,CARS,Beijing 100081,China;State Key Laboratory for Track System of High-speed Railway,Beijing 100081,China)

机构地区：[1]广东大潮高速公路有限公司,广东梅州610036 [2]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [3]高速铁路轨道系统全国重点实验室,北京100081

出　　处：《铁道建筑》2025年第2期120-125,共6页Railway Engineering

基　　金：中国铁道科学研究院集团有限公司青年基金(2022YJ107);中国铁道科学研究院集团有限公司重点基金(2022YJ126)。

摘　　要：针对松散岩堆体边坡成孔难度大、锚索安装难等问题,提出一种钢花管与预应力锚索组合结构新技术。依托广东大潮高速公路某滑坡治理项目开展现场拉拔试验,结合锚索锚固理论,研究钢花管内植入不同数量的钢绞线及在受荷状态下的内部力学响应,总结新型钢花管与预应力锚索组合结构的预应力损失规律。结果表明:在松散岩堆体地层中,直径为76 mm的钢花管内植入4束钢绞线的组合结构的锚固力与普通预应力锚索相比得到大幅提升,该组合结构的最大锚固力达到567 kN,约为传统4束钢绞线锚索结构的2倍;在对钢绞线施加预应力时,通过监测钢花管表面应变数据发现,自由段钢花管承受压应力,锚固段钢花管承受拉应力,钢花管受力随着钢绞线预应力的增加而增大;对钢花管与预应力锚索组合结构的锚固力进行长期观测,发现在张拉完毕后的瞬时预应力损失较大,约为14.87%~18.35%,但长期预应力损失仅为6.07%~7.56%,表明该结构能够在长期使用中保持稳定,有利于长期应用。此外,长期预应力损失率与钢花管直径呈现明显的负相关关系。A new technology called prestressed steel anchor pipe anchor cable combination structure is proposed to address the difficulties of drilling holes and installing anchor cables in loose rock mass slopes.Based on the landslide control project of Dachao Expressway in Guangdong Province,on-site pull-out tests were conducted,combined with anchor cable anchoring theory.The optimized combination of different numbers of steel bars implanted in the steel pipe and the internal mechanical response mechanism under load were studied,and the loss law of prestress in the new composite structure was analyzed.The results show:In loose rock formations,the anchoring force of the composite structure with 4 bundles of steel strands implanted in the 76 mm steel flower tube has been significantly improved,and the maximum anchoring force of this composite structure reaches 567 kN,which is about 2 times that of the traditional anchor cable(4 bundles)structure;When applying prestress to steel strands,it was found through monitoring the surface strain data of the steel flower tube that the free section of the steel flower tube bears compressive stress,while the anchoring section of the steel flower tube bears tensile stress.Moreover,as the prestress of the steel strands increases,the stress on the steel flower tube continuously increases;Long-term observations on the anchoring force of the combined structure of steel-flowered pipe and prestressed anchor cable show that there is a significant instantaneous prestress loss immediately after tensioning,ranging from approximately 14.87%to 18.35%.However,the long-term prestress loss is only 6.07%to 7.56%,indicating that the structure remains stable over prolonged use,which favors its long-term applications.Additionally,a notable negative correlation is observed between the long-term prestress loss rate and the diameter of the steel-flowered pipe.

关 键 词：钢花管与预应力锚索组合结构 力学响应 锚固机理 现场拉拔试验 预应力缺失 

分 类 号：U213.158[交通运输工程—道路与铁道工程]