Misplacement of Launching Bearings in PC Launched Bridges

Abstract

In the incremental launch of a prestressed concrete (PC) bridge, the deck is a continuous beam that moves over fixed bearings. Their vertical misplacement causes secondary stresses that sometimes can be resisted by the deck, but that other times require expensive compensating devices. An original theoretical model permits an analysis of this phenomenon and the optimization of the interaction between torsion and distortion. This results in a more agile, faster analysis than finite-element analysis, which requires sophisticated, laborious models and does not distinguish between the two phenomena.