Research On Forecasting Invertedcamber Of The Reinforcement Of External Prestressing Bridge By The GM Method

With the expeditious development of our civil traffic projects, most bridges aresuffering from surcharge load and heavy load in their carrying capacity and structuralbehaviour, and the most common and severe defect is the bridge cracking problem ordeformation, which has seriously affected the normal usage of bridges.It’s necessary takingsome reforcment method in order to lengthen the serviceable life.The strengthening techniqueby use of the external prestressing method has been widely used because of activestrengthening, simple and convenient construction,reliable structure and the economy of thecost.Otherwise,with more and more high-strength materials are used in bridge structures,thesectional detail is becoming smaller and smaller and its span is increasing.Compared toordinary constuction the influence of deflection is becoming more sensitive,so it isparticularly important to prevent too large deflection or invertedcamber.This paper as an important component of dynamic quality tracking research in theexisting bridges of the department of communications of Guizhou Provice and as backgroundof the strenthened bridges of GuiXin road. Through precedent extensive research the paperalso comprehensively summarized the key points of the construction technology andconstruction control, and summed up the research achievement about the deflection of theexternal prestressing calculation method,analysed the influcing factors of the externalprestressing deflection.Theoretically,it has some feasibility using the grey system theory topredict the deflection on condition that the deflection and its influcing factors are regarded asgrey variables.Based on this thinking,this paper focus on the adhibition.First of all,this paper comprehensivly summarized the external prestressing reinfoercdtechnology,and trimmed the research results of the calculation method about the deflection ofthe external prestressing structurs at home and abroad, used SAP2000to simulat each stageof constrction,analysed the influcing factors. Based on the theoretical principles of greysystem theory,built a single variable order GM(1,1) model,which takes the error betweentheretical and measured value as the altermating quantity.At the same time,it used MATLABanalysing the alteration of the delection which is influnced by longterm effect determinants,and updated the theretacal value.At last,a case has been analyzed to validate theveracity and reliability of the gray model.Well,it also has a very useful reference for thesimilar reinforeced methods.