公路土质边坡全长黏结锚杆拉拔极限荷载研究  

Research on Pull-out Ultimate Load of Full-length Bonded Anchor Rod for Earth Slope of Highway

作　　者：张亚卿[1] 武博强 冯军强 张葆永 王勇 余贤元 ZHANG Ya-qing;WU Bo-qiang;FENG Jun-qiang;ZHANG Bao-yong;WANG Yong;YU Xian-yuan(CCCC First Highway Consultants Co.Ltd.,Xi'an 710075,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,西安市710075

出　　处：《公路》2025年第1期115-121,共7页Highway

基　　金：国家重点研发计划课题项目,项目编号2016YFC0802203。

摘　　要：为在设计阶段更合理地确定全长黏结锚杆极限荷载,在前人的研究成果基础上,以在建高速公路项目土质挖方边坡为研究对象,基于FLAC3D,提出了在设计阶段通过数值分析研究拉拔力加荷与锚杆位移及位移增量双重判据的关系以确定极限荷载的方法。首先建立边坡模型分析加固前后的边坡稳定性,得到设计锚固力;然后分析不同加荷工况下的位移及位移增量关系,通过拐点法和规范法共同确定极限荷载,并提取锚杆轴向力获得水泥浆与锚杆界面的剪应力,分析界面剪应力与锚固深度的关系;最后通过施工阶段的拉拔试验进行对比校核。对比结果显示,在土体及加固锚杆物理力学参数准确的前提下,通过数值模拟分析不同加荷工况下的锚杆端头部位移及位移增量与荷载的关系确定出的极限荷载与拉拔试验最终确定的极限荷载完全一致。这说明,在设计阶段完全可通过数值分析确定不同岩土体情况下锚杆的极限拉拔荷载,并对设计锚固力与极限荷载进行数值对比,当设计锚固力大于极限荷载时再考虑施加预应力或选择其他支护形式,解决了设计中由于无法确定极限荷载而采用固定设计值导致设计偏保守的难题,进一步提升了设计阶段指导施工的准确性与合理性。In order to determine the ultimate load of the full-length bonded bolt more reasonably in the design stage,based on the previous study results,the soil excavation slope of the highway project under construction is taken as the research object,Based on FLAC3 D,a method of determining the ultimate load by numerical analysis of the relationship between the pull-out force loading and the displacement and displacement increment of the bolt is proposed.Firstly,the slope model is established to analyze the slope stability before and after reinforcement,and the design anchorage force is obtained.Then,the relationship between displacement and displacement increment under different loading conditions is analyzed.The ultimate load is determined by the inflection point method and the specification method.The axial force of the bolt is extracted to obtain the shear stress at the interface between the cement slurry and the bolt,and the relationship between the interface shear stress and the anchorage depth is analyzed.Finally,the pullout test in the construction stage is compared and checked.The comparison results show that under the premise of accurate physical and mechanical parameters of the soil and the reinforced anchor rod,the ultimate load determined by the numerical simulation analysis of the displacement of the head of the anchor rod and the relationship between the displacement increment and the load under different loading conditions is completely consistent with the ultimate load determined by the pull-out test.This shows that in the design stage,the ultimate pull-out load of the bolt under different rock and soil conditions can be determined by numerical analysis.The design anchorage force is numerically compared with the ultimate load.When the design anchorage force is greater than the ultimate load,the prestressing force is considered or other support forms are selected.The problem of conservative design due to the inability to determine the ultimate load and the use of fixed design values in the design is solve

关 键 词：道路工程 边坡支护 全长黏结锚杆 拉拔极限荷载 FLAC3D 位移~荷载曲线 

分 类 号：U416.1[交通运输工程—道路与铁道工程] P642.131[天文地球—工程地质学]