Study On The Final Closure Technology Of Hybrid Girder Cable-stayed Bridge Under The Undesigned Condition

With the increase of cable-stayed bridge span,bridge structure becomes more complex,bridge construction is more and more difficult.In the main span closure construction as the bridge linking the controlling process,will be affected by temperature,cable force,linear beams,structure system transformation,temporary load placed factors,such as construction quality fit and unfit quality will directly affect the stress state of the whole structure and service life.In order to guarantee the smooth across the final closure,which makes the bridge into the bridge state of linear and internal force and the design perfectly,long-term studies should be carried out to the mid-span closure technology.In this paper,by taking Chongqing rail link garden Gao Bridge as the engineering background,using finite element software MIDAS/Civil 2015,system hybrid girder cable-stayed bridge is studied under the condition of the design of the joining key technology.The main research work includes papers:1?Simply introduces the Chongqing rail link garden Gao Bridge modeling ideas and methods of the whole bridge finite element model,and cable force,main girder of the bridge at construction stage accumulated deformation and internal force of main girder and so on has carried on the analysis and calculation,it is concluded that the calculation results meet the specifications and design requirements,the bridge construction status to normal.2?Of cable-stayed bridge under the condition of low temperature the temperature cutting closure method,the geometric control method and the seaming closure method to carry on the simulation,a detailed analysis of the above three kinds of the final closure for the closure method under the condition of four types of low temperature on the influence of the bridge into the bridge state,by comparing the additional cable force,main girder,additional stress,additional deformation of main girder,main tower additional migration and site construction technology,the view that are preliminarily closure temperature difference at 20? to 10?,appropriate uses the seaming closure method,the final closure temperature difference in 10? ~ 5?,joining the seaming closure method or the geometric control method,the final closure temperature difference within 5?,appropriate temperature cutting closure method.3?Studying the calculation method of closure pusher displacement and jacking force,put forward based on the rigid support continuous beam method,and combine the temperature effect of the displacement equation of beam body temperature shrinkage method.It is concluded that the cable-stayed bridge girder under different temperature shrinkage value.Through the analysis of the factors that influence the girder pusher.The jacking force calculation formula is obtained,and combining the formula of jacking force of cable-stayed bridge has carried on the detailed calculation,put forward based on the key factors of influence matrix method to the formula target hanger forces method.The main girder is obtained in the process of pushing the target and then identify the pusher displacement and the relationship between the jacking force.4?For the on-site seaming closure method has carried on the summary analysis,detailed comparison and analysis of the final closure pusher displacement and jacking force difference and contact of measured value with the theoretical value.Pusher displacement measured value with the theoretical value is smaller.This paper is proved the feasibility of the calculation method of beam body temperature shrinkage.Jacking force change rule,the deflection measured value with the theoretical value but also has a link between the two,the measured values,always focus on the theoretical value changes are not completely from the theoretical value,and illustrates the theoretical value has a certain guiding role.