Investigation On Tangential Stiffness Of Prestressed Anchorage Structure’s Contact Interface

Prestressed anchorage structure is widely applied in bridge and tunnel engineering,geotechnical engineering and other fields.The main feature is improve the bearingcapacity of structure,stability and security.However,too much loss of prestress ofprestressed anchorage structure or failure problem don’t make the structure reach thelevel of design goals and structural failure destruction.According to the forcetransmission characteristics of prestressed anchorage structure,the contact ofanchorage and anchor plate transformation for the contact problem of roughsurface.This paper is combine the Hertz contact theory with the GW model,and putforward the analytical solution of tangential stiffness of prestressed anchoragestructure’s contact surface,and modification-MB fractal model of the tangentialstiffness,outdoor model test results are compared,proves the applicability andreliability of the formula.This paper provides a theoretical basis for the research on thetension of prestressed anchorage structure detection principle and the method.Thework of the research and the results basically has the following four aspects:1.According to the two spherical asperities are pressed by normal and tangentialloads,and considering the partial slip condition,apply to combination of the knownHertz stress distribution to structure the more accurate and reasonable stressdistribution of contact of single-peak,and put forward the analytical solution oftangential stiffness of prestressed anchorage structure’s contact surface.The resultsshow that the friction coefficient of the contact interface is relatively small on theeffect of tangential contact stiffness;and the equivalent of the effect of surfaceroughness on the tangential contact stiffness is bigger than friction coefficient.Withinthe elastic range,there is a one-to-one function relation of prestressed anchoragestructure of tangential stiffness and contact surface normal tension.2.In this paper,completed the prestressed anchorage structure(screw nut type) ofthe static load test,measuring the anchoring structure’s contact surface tangential static elastic displacement under the action of surface tangential force.3.The theoretical calculation formula, the static load test of tangential andcorrection-MB fractal contact model for effective tension anchor structure (normalload) and tangential contact stiffness relationship curve were analyzed.The resultsshow that the contact of prestressed anchorage structure interface tangential stiffnesscalculation formula was consistent with the results of static load test of tangential,withappear consistent regularity of modification-MB fractal contact model for tangentialstiffness answers.4.Prestressed anchorage structure tension test route, process and methods hadmade detailed in this paper.