论文部分内容阅读
在25个室内模型试验基础上,研究了均质砂土中竖向拉拔扩体锚杆的几何尺寸及埋深对其承载特性的影响。试验结果表明,根据深径比的不同,扩体锚杆可以分为浅埋与深埋扩体锚杆2种形式,它们在拉拔过程中均经历了土体弹性变形阶段、非扩体锚固段-土界面剪切破坏阶段、土体弹塑性变形阶段以及剪切破坏阶段,破坏特征分别表现为整体剪切破坏与局部剪切破坏。通过扩体锚杆与普通拉力型锚杆模型试验对比发现:与普通拉力型锚杆相比,扩体锚杆极限承载力、承载比与安全性均有大幅度提高。而通过增大扩体锚固段直径的方式提高扩体锚杆承载力的优势较为明显。此外,根据承载比分析,扩体锚杆存在最优扩体锚固段直径,因此,在实际工程中应寻找一个满足需要的最优扩体锚固段尺寸以取得较好的经济效益。
Based on 25 indoor model tests, the influence of the geometrical dimension and depth of the vertically-drawn bolting in the homogeneous sand on the bearing characteristics was studied. The test results show that, depending on the ratio of depth to diameter, the two types of extended-depth anchors can be divided into two types: shallow-buried and deep-buried anchors. Both of them experience elastic deformation during drawing, In the stage of shear failure of the segment-soil interface, the elastic-plastic deformation phase of the soil mass and the stage of shear failure, the failure characteristics are shown as the total shear failure and the local shear failure, respectively. Comparing with ordinary tensile anchor bolt test, it is found that the ultimate bearing capacity, bearing ratio and safety of expanded anchor bolt are greatly improved compared with ordinary tension anchor bolt. However, the advantage of increasing the bearing capacity of the expansion anchor by increasing the diameter of the expansion anchor is obvious. In addition, according to the analysis of bearing ratio, there is an optimal diameter of the anchor segment expansion, so in the actual project should find a suitable size to meet the needs of the optimal anchor segment to obtain better economic benefits.