Force Analysis And Key Technology Research Of Steel Truss Bridge In Dragging Construction

With the rapid development of China's bridge industry,steel truss bridges have also developed rapidly in bridge construction,steel truss bridge has the characteristics of beautiful appearance,high gravity rigidity and good stability.Dragging construction is a common construction method in steel truss bridge construction,especially in cross-road,cross-river,cross-valley,and cross-line construction,it has obvious advantages.Its construction method has the characteristics of short construction period,does not affect the existing traffic,and is safe and reliable.This article takes the 96 m steel truss bridge of the Weilai Qingrong down link line across the Qingrong railway bridge as an example.To elaborate the towing technology and construction process of large-span simply supported steel truss beams,optimized the design of the guide beam plan,the stress,deformation and stability of the bridge in the process of dragging construction are analyzed.(1)The construction process and construction principle of towing method and jacking method were compared and analyzed.The temporary facilities during towing method construction were studied.The distribution of temporary support horizontal force during the towing process was analyzed.(2)Combined with engineering examples,the guide beams in haulage construction were optimized,and the optimal guide beam design was determined by studying the influence of main beam weight,guide beam length,and guide beam height on the stress and deformation of the structure.(3)The finite element software Midas / Civil is used to model the steel beams in various construction stages,the towing of the whole bridge is divided into 16 construction stages,The changes of bearing reaction force,internal force,stress and deformation of each member in each construction stage were studied,the buckling analysis and anti-overturning stability calculation of the structure were also carried out.(4)The influence of train wind load on the steel truss beam during towing construction was studied,and the stress internal force and deformation time-history curve of the steel truss beam were analyzed.