Serviceability of segmental concrete arch-frame bridges built by cantilevering

Abstract

The evaluation of the safety degree in service life for a segmental prestressed concrete bridge built by the cantilever method, presents different aspects related to strength, deformability, durability and to effects of time-dependent phenomena as creep and shrinkage. The case-study of a prestressed concrete frame bridge with inclined piers is presented, built by cantilevering, with precast segments. By considering the fundamental items of design and construction stages, the implications due to the arch effect in this static scheme are investigated, with respect to an equivalent bridge with a final scheme of continuous girder on vertical piers. The birth of a significant value of axial force in the main span is considered and the stress redistribution in time due to the effects of creep on the static scheme change during construction is analysed. The main parameters involved are underlined and results in terms of serviceability and ultimate limit state are obtained. Finally aspects related to durability are considered and analysed in the presented case-study.