Research On Anchorage Mechanism Of Full-length Bonded Anchor

As the key to engineering anchoring technology,anchor rods not only have excellent mechanical properties,can give full play to the strength of the rock and soil itself,but also have relatively low prices,which can greatly reduce engineering costs.With the development of my country’s infrastructure construction,anchoring technology has become more and more widely used in major anchoring projects such as slope protection,urban foundation pits,and underground tunnels.However,in actual engineering,the analysis and optimization of the anchoring performance of anchor rods are often neglected,which leads to blindness in the selection of many anchor rod parameters,and the value of anchor rods cannot be fully utilized.Therefore,the research on the reinforcement mechanism of the bolt has become an important research topic.Based on literature investigation,indoor bolt pull-out test and numerical simulation,this paper explores the anchoring mechanism of the full-length bonded bolt under pull-out load.Through previous literature research,the results and shortcomings that have been achieved so far are summarized;single factor analysis method is used to carry out pull-out tests on 12 groups of bolts under different working conditions,and the failure forms and shapes of different bolts are analyzed..The four influencing factors of anchor rod anchorage length,anchor rod diameter,anchor rod shape and anchoring agent strength were compared respectively,and the shear stress distribution curve of the anchor rod interface under different working conditions was analyzed.The results show that the shear stress distribution of the anchor rod rises first and then decreases.In the elastic stage,the shear stress of the anchor rod is mainly concentrated near the orifice,and the shear stress at the end of the drawing is 0.With the gradual increase of the load,the position of the shear stress peak gradually moves to the distal end;the ultimate pull-out load of the anchor rod increases with the increase of the anchoring length,which is roughly linear,and the critical anchorage of the 16mm anchor rod is inferred The approximate range of length.In addition,the shape,diameter and strength of the anchor rod have a significant impact on the pull-out bearing capacity of the anchor rod.Finally,using the Abaqus finite element analysis software,based on the cohesion element and the concrete plastic damage model,a numerical simulation study was carried out,and a comparative analysis was carried out with the test results,and a conclusion of certain engineering guiding significance was obtained.