Analysis of External Prestressing Effect on Flexural Performance of Composite Steel Box-concrete Continuous Girder Bridge

Abstract

He total construction process of three-span composite steel box-concrete continuous girder bridge having varied cross-section was analyzed by using spatial finite element method. The external prestressing effect on flexural performance of composite steel box-concrete continuous girder bridge was emphatically studied. The element creation technique was adopted to simulate the total flexural process of composite steel box-concrete continuous girder bridge. The analysis results show that when the main span of composite steel box-concrete continuous girder bridge is longer and its cross-section size is limited, the strength requirement of negative moment region at middle support cannot be satisfied by using the conventional measures such as forced top-pier displacement, internal prestressing on bridge deck, etc. The local external prestressing on the bridge deck of the negative moment region at middle support has greater effect on improving the flexural performance of composite steel box-concrete continuous girder bridge. The load carrying capacity and spanning ability of composite steel box-concrete continuous girder bridge can be increased, which will bring greater integrated economic benefits.