Stress Analysis Of Prefabricated Small Box Beam With Cracks

The Precast box girder’s construction method is simple and feasible, andlow cost,standardization,the girder is easy to maintain and against the earthquake.So the prefabricated box girder is used widely in the bridge with the span of20to40m. It has used widely in the highway and city.But now it’s also difficult to totally understand the force. In the constructionsite, the quality’s fluctuation is in a large range. The emerge of crack is a bigproblem. After the girder appears the crack, the rebar will get rusty quickly,whichis so dangerous, that we must pay attention. In this paper, the practical problems aencountered in one project. After tests in the site were done, the finite elementmethod is used to simulate the bridge tests. The influence of the crack to thegirder and the whole bridge a study. This article is a reference to the deep study ofthe influence to girder, the following works have been done:1、Based on the problems encountered in engineering practice, finite elementmodels are established，to analysis the box girder’s cracks and the carryingcapacity, the girder’s security and reliability are determined.2、The force analysis of the girders in the bridge are studied, under Point loadand Vehicle load.3、Based on the results of the girder static load test on the site, the FEAmodel is calibrated, then it is used girder whole bridge to determine thesafety.