Research Of The Half-continuous Girder Method To Refit Simply Supported Girder Bridge

It has become a worldwide problem to refit the unsafe bridges, with which we can ensure traffic free at lesser cost and can avoid the bad effect. At the same time, the Country's highroad net is almost perfect and the amount of the new bridges is dimishing, so how to maintain and refit the exist bridges has become primary work for departments of communications. The simply supported girder bridges play a important role in highroad buildings, so it is necessary to research for a good way to refit them.This paper put forward a new structure of half-continuous girder bridges, which can improve their carrying capacity at lesser cost and needn't stop traffic. Anchoring armer plate or high strength bolt near the neutral axis, at the same time using rigid block down the neutral axis can realize the bridge system change. The half-continuous girder method needn't get rid of the upper deck of bridge and just be constructed under bridges, don't disturb the traffic. So by use of the half-continuous girder method to refit simply supported girder bridges is right choice. This paper first do a feasibility study, then bring forward a calculation model and computational scheme. Based on the model and scheme we make use of finite element method and calculate a 2-span, a 3-span and a 5-span half-continuous girder. The result indicate that all the structures'carrying capacity have been improved obviously and the whole bridge's flexural rigidity has also been enhanced. All these results prove the calculation model and computational scheme is right. At last, the model test testify the veracity of the calculation model and computational scheme of the half-continuous girder bridges.At the this time, traffic become more and more busy, but the half-continuous girder method needn't disturb the traffic and also can improve their carrying capacity, so it is a bright choice to refit the unsafe simply supported girder bridges. We can foresee its great foreground.