Investigation About Reconstruction Technology Of Widening For Rigid-frame Arch Bridge Of Reinforced Concrete

With the growth of the volume of traffic and technological transformation of the highway, this paper proposed reconstruct technology of widening for rigid-frame arch bridges. Because of the deck width of bridges floor, the volume of traffic can not reach the highway rating requirements, many old bridges have become"bottleneck"on highway transportion artery in our country. In order to improve the bridge capacity, suitable for the broaden highway route, it's urgently to investigation about reconstruct technology of widening for existed rigid-frame arch bridges.First of all, this paper introduces the origin and development, summarizes the common way of evalution, and puts forward the common forms and methods about reconstruct technology of widening for rigid-frame arch bridges.Secondly, this paper introduces the structure characteristics, the mechanics characteristic and computional theory and method of rigid-frame arch bridge.According to the theory, the author establish plane finite element model of the original bridge and find the existence of the weak link.Combined with practical problems, the author proposes solutions to the problems of thinking and the transformation method.Then,the author establish plane finite element model of the widened bridge, and analysis the static state under the dead load ,live load and combination load,using Dr.Bridges plane fininte element analysis software. After the new and the old rib stitching, the upper part of the original structure of the bridge due to the impact of the new part of the bridge, the superstructure stress produced change.Combined with a space"MIDAS/FEA"finite element model, the author do comparative analysis about the force of the original bridge and the new.With the stiffness of the new arch and the junction beam increasing, We can find the bearing capacity of the original structure will improve.Finally, through the research of reinforced concrete frame arch bridge on the widening reconstruction technique, the author proprose buried rib shear reinforcement at the junction of the old and the new loction.To implant anchorage in the original arch ribs, when the new beams and slightly curved board structure pouring, through anchorage the new and old arch rib together into a whole, to achieve the common good and the overall work force purposes.Though the numerical method of time delay widening the bridge to shrinkage and creep analysis ,the delay time can be effectively improve splicing shrinkage and creep on the impact of widening the bridge.