Study On Shear Lag Effect Of Bridge Slab In Construction Of Composite Beam Cable-stayed Bridge

The most obviously feature of the composite girder cable-stayed bridge is that the common force between the bridge deck and the steel girder through the shear connection.The steel beam and bridge deck at the anchorage point of the main beam will produce severe stress concentration under the tension of the cable,which is different from the stress of the bridge deck analyzed by the elementary beam theory.If this phenomenon is not taken into account,it may lead to Local damage.Therefore,it is necessary to analyze the space effect of the bridge deck of the long-span overlay cable-stayed bridge to ensure that the stress is in a safe and controllable range.Although many scholars at home and abroad have done a lot of research on the bridge deck of the overlapped beam cable-stayed bridge,many practical results have been obtained,but mostly for the shear lag of the bridge Analysis,for other factors that may affect the shear lag effect of the bridge deck(such as the construction process,temperature changes,shrinkage of concrete creep)to consider less.Based on this,this paper uses the finite element method to do the following work with the background of a large span overlay cable-stayed bridge:(1)Through the collection of a large number of literature,this paper summarizes the development of the composite girder cable-stayed bridge at home and abroad,and the research methods of the shear lag effect of the bridge deck.(2)The spatial model which is composed with beam,rod,shell and spring is established by the ANSYS finite element software.(3)Taking the maximum cantilever stage in the construction process as an example,the influence of the temperature effect which including the whole temperature's rise or fall and the local temperature between the bridge deck and steel beam on the horizontal distribution of the bridge deck is calculated and analyzed.(4)The results that the wet seam grouting process in the construction process of the composite beam will have a significant effect on the stress of the steel girder and the bridge deck.In this paper,the wetting joints of the bridge deck are considered to be lagging once,lagging twice and not lagging.The effects of different hysteresis processes on the stress of steel girder and bridge deck are analyzed.(5)In the construction process,assuming that the cable's tensioning of middle and side span,the middle and left not asymmetric,and the stress effect under the twoconditions on the bridge deck is calculated and analyzed.(6)The displacement and internal force of MIDAS CIVIL are used to load the two-terminal boundary condition,and the non-linear spring element COMBIN39 is used to simulate the shear.The effect of the shear slip on the stress of the bridge deck is analyzed.In this paper,a large span composite cable-stayed bridge is taken as an example.The finite element method is used to analyze the shear lag effect and some useful conclusions are obtained.This can bring a certain reference value for the same type of bridge design...