A Fast Calculation Method for Camber of Concrete Arch Bridges with a Span of 100 m-150 m Based on Specific Steel Arch Centerings
For the camber calculation of the specific steel arch centering used in concrete arch bridges with a span of 100 m～150 m,a method was proposed to quickly calculate the camber of steel arch centering using the deformation under the action of self-weight of the arch ring and the deformation ratio of the steel arch frame caused by the concrete pouring.In order to obtain the deformation ratios of steel arch centering for different ratios of rise-span and arch axis coefficients,an auxiliary program was developed to establish a Midas/Civil finite element model by importing MCT files,which can achieve rapid modeling of the entire process from defining elements,boundary conditions,construction stages,and joint sections during construction.The arch ring concrete was poured into three layers:the bottom plate,the web plate,and the top plate,the coaction of the steel arch centering and the arch ring was considered.A calculation formula for the camber of the steel arch centering was given.The calculation results show that for concrete arch bridges with common ratio of rise-span and arch axis coefficient,the average ratio of deformation caused by arch ring poured into layerers to arch ring by self-weight was 4.37-4.88.However,to facilitate the calculation of elastic deformation of steel arch centering,it was recommended to uniformly set the deformation ratio as 5.0.The method was applied to the calculation of the camber of the steel arch centering of a concrete arch bridge with a net span of 135 m.The maximum error between the elastic deformation of the steel arch centering obtained by the proposed method is 4.30%,which could meet the engineering accuracy requirements.It's indicated that the method proposed in the paper is reasonable and feasible,which can be proposed and applied on calculation of camber for steel arch centering of concrete arch bridge.
concrete arch bridgesteel arch centeringlayer by layer pouringcalculation of camberratio of deformationdeformation of arch ring by self-weight
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