Review of Study of Long-term Deflection for Long Span Prestressed Concrete Box-girder Bridge*

Long-term deflection of long span prestressed concrete box girder bridges (LSPCBB) is getting ever more serious in terms of structural safety. And there are still many ambiguous reasons as to the cause of the deflection of LSPCBB. In consideration of the causes of long-term deflection, domestic (Chinese) and abroad research literature on the deflection problems of LSPCBB are reviewed and analyzed taking into account concrete creep and shrinkage, prestress effect, box-girder cracking, calculation, and retrofit methods. Not only are the cause mechanism and research difficulties of the deflection explained, but also the suggestions about further research of long-term deflection control in design calculation, construction, and retrofit technologies of LSPCCB are presented.