充气膨胀控制型锚杆的承载性能研究

Study on bearing capacity of inflatable expansion control anchors

为深入、系统地研究充气膨胀控制型锚杆的承载性能,考虑充气压力、挤土管片厚度及挤土管片外表面粗糙度的影响,制作了5组充气膨胀控制型锚杆和3组传统注浆锚杆,在相同的地质土层中进行了锚杆拉拔试验。依据试验加载现象和试验数据对这5组充气膨胀控制型锚杆的承载性能进行了深入、系统的分析,通过绘制荷载-位移曲线对比分析了不同试验组充气锚杆的承载能力。结果表明,充气压力、挤土管片厚度及挤土管片外表面粗糙度的增加均可提高充气膨胀控制型锚杆的承载性能。对比传统注浆锚杆,充气膨胀控制型锚杆的承载能力和抵抗变形能力更强,具有重要的工程应用价值。进一步基于圆孔扩张理论推导出充气膨胀控制型锚杆的承载力计算理论公式,极限承载力理论值与试验值较为符合,为该型号锚杆的工程设计及运用提供了理论依据。

In order to deeply and systematically study the bearing capacity of inflatable expansion control anchors, five groups of inflatable expansion control anchors and three groups of traditional grouting anchors were made in this paper to investigate the influence of the inflation pressure, the thickness of the extruded segment and the surface roughness of the extruded segment.The anchor pull-out test was carried out in the same geological soil layer.According to the test loading phenomenon and test data, the bearing capacity of inflatable expansion control anchors in five different experimental groups was analyzed deeply and systematically.By drawing the load displacement curves, the bearing capacity of different test groups of inflatable anchors was compared and analyzed.The results show that the increase of inflation pressure, the thickness of soil-extruded segment and the roughness of the outer surface of soil-extruded segment can improve the bearing performance of inflatable expansion control anchors.Compared with the traditional grouting anchors, the bearing capacity and the ability to resist deformation of inflatable expansion control anchors has been improved, which has important engineering application value.Based on the theory of circular hole expansion, the theoretical formula of bearing capacity calculation of inflatable expansion control anchors has been deduced.The theoretical value of ultimate bearing capacity is in good agreement with the experimental value, which provides a theoretical basis for the engineering design and application of this type of anchor.