Study On Feedback Control Of Long Span Concrete Cable Stayed Bridge Based On Influence Matrix Method

Long-span cable-stayed bridge construction passes through a complicated process,and in this process will be affected by many certain and uncertain factors,the effect of lead to actual state deviates from the theoretical calculation and analysis of the structure of the bridge.Therefore,the focus of the bridge construction control is through the analysis of deviation in the construction control of recognition,find problems and timely rectification,to predict subsequent stages of the structure at the same time,make the construction system under control all the time.In recent years,the cable-stayed bridge construction technology has made great development in our country,so the research of long-span cable-stayed bridge construction control is becoming more and more important.The construction control is an important guarantee to the construction process of the final state of the bridge meet the design standards,and feedback control is the main construction method of large span cable bridge construction.Through the feedback of checking construction at the current stage,and the next phase of the predictive value of real-time adjustment,ensure the structure of the final bridge line and the internal force state meet the design and design of state or state error is within the allowable range.In order to form a set of simple and feasible feedback control method,based on the construction of Sichuan Dazhou Gold South Bridge In order to support the project,the feedback control based on the influence matrix method is applied to the construction:(1)The current mainstream feedback control based on the grey theory and Calman filter method are briefly introduced,through the establishment of grey theory,grey dynamic model,the feedback correction and prediction,effective control of the cable-stayed bridge.This method can make a modification to the model,which is established by using grey model of the residual data.And the result is added to the original model,but it brings a great amount of work,and the correction is limited.It is a kind of probability thought,is in the collection of certain samples,forecast,collection precision and sample prediction about;and Calman can be through continuous filtering method change the cable to repair The linear error of the main girder,but this method not only increases the workload of the construction,but also constantly change the cable force of the cable,which has a negative impact on the internal force of the mainbeam,increasing the cumulative error.(2)The feedback control based on matrix method is studied,explored the calculation methods.This paper has two key research,one is the error in the construction,how to adjust;two is in error after adjustment,how to predict the next phase of the vertical mold elevation and cable force.To solve the two points through the influence matrix to calculate the current construction segment in the presence of errors,the subsequent construction stage according to the design of cable shape and force construction,the bridge design and bridge state comparison,determine if you need to adjust,if we need to adjust through the influence matrix of cable adjustment,the bridge internal force and alignment is reasonable the next stage,and the prediction of form work Elevation and cable forces.(3)In the construction of Sichuan Dazhou gold bridge south bridge as the project background,based on the influence matrix method of long span concrete cable-stayed bridge construction stage of the construction of linear feedback correction and prediction of the next stage and the cable force implementation process and calculation method are introduced in detail,combined with Midas Civil finite element model to determine the the internal force and alignment of bridge,and using the method of the construction stage is evaluated.