Experiment And Numerical Simulation On Working Mechanism Of Pressure-dispersive Anchor

With the development of infrastructure construction in China,the prestressed anchorage technology has been more and more widely used in various fields of rock and soil reinforcement,and the pressure-dispersive anchor has been more and more applied to such projects as foundation treatment,slope anchorage,tunnel reinforcement and so on.At present,the research on this kind of anchorage structure is mostly concentrated on the macroscopic force,but the study of its mesoscopic mechanism is few.It is difficult to analyze the anchorage mechanism of the pressure-dispersive anchor from the micro level.The indoor visual simulation test is carried out to study the anchorage mechanism of pressure-dispersive anchor under the static load at micro levels in this paper.Based on this,the mesoscale numerical simulation plat form was established by discrete element bumerical simulation software PFC.The mesoscopic mechanical parameters change rule of sourrounding soils around pressure-dispersive anchor under the action of the external load was simulated and analyzed to reveal the mesoscpoic mechanics mechanism.The concrete research content is as follows:(1)Visualization model experiment on mechanical performance of pressure-dispersive anchor.The model of pressure-dispersive anchor was designed and made to carry out the pull-outs tests of under axial load.The mesoscopic structure evolution law surrounding sand around the pressure type anchor was analyzed and studied by using digital photogrammetry and image correlation analysis.(2)Numerical simulation research on anchorage mechanism of pressure-dispersive anchor.Based on the theory of particle flow and PFC program,the numerical simulation model of pressure type anchor and pressure-dispersive anchor was set up,and the stress state of anchor under axial load is studied.The axial stress and shear stress of the simulation model of pressure type anchor and pressure dispersion anchor are compared and analyzed.At the sametime,through the study of the physical and mechanical parameters,such as displacement field,stress field,rotation amount,particle size,the mesoscopic anchorage mechanism of pressure dispersed anchor bolt is revealed.(3)Numerical simulation research on influencing factors of anchorage mechanism of pressure-dispersive anchor.Considering the factors such as compactness of different sand soil,different burial depth anchor plate,the model of pressure dispersive anchor is established by using PFC program to simulate and study the mechanical behavior of pressure dispersive anchor.