Research And Analysis About Extended Structure Of P.C. Continuous Box Girder

In highway extended project, the extended methods of P.C. box girder bridge and interactional effects between new box girder and old box girder is the most important problem. According to LuMu Bridge which lies in HuNing Highway, article makes a systematical research about box girder's loaded performance and connection form in expended P.C. continuous box girder bridge. Main research contents included effect of concrete shrinkage, creep, differential settlement of foundation, change of temperature, vehicle loading, compares different performance of two kinds connection form, rigid connection and hinge connection.The results shows: due to effect of vehicle loading and change of temperature, old P.C. box girder's loaded performance has been improved after expended with hinge connection form. All kinds partial action, such as concrete shrinkage, creep, differential settlement of foundation, change of temperature, vehicle loading influences girder and flange plate's loaded performance in longitudinal and lateral direction. Especially effect of differential settlement.Compare with two connection forms in expended P.C. continuous box girder bridge find out , rigid connection will increase concrete stress in lateral direction, on average increase extent can reach 15%~20%.