Artículo:

Excessive Deflections of Record-Span Prestressed Box Girder

Autor:

Zdenek P. Bazant

Qiang Yu

Guang-Hua Li

Gary J. Klein

Vladimir Kristek

Resumen:

When completed in 1977, the Koror-Babeldaob Bridge in Palau held the world-record span of 241 m (790 ft) for segmentally erected prestressed concrete box girders. Within 18 years, its total deflection, compared with the design camber, reached 1.61 m (5.3 ft.) and the prestress loss was measured as 50%. In 1996, the bridge was retrofitted, but three months later the bridge suddenly collapsed. It wasn’t until 2008 that the technical data necessary for complete analysis were released. This article shows that the existing models for creep and shrinkage prediction grossly underestimate the deflections and prestress loss, although one model, model B3, does so much less than the others and, if calibrated by the 10-year tests of Brooks, matches the observations.

Página:

44

Publicación:

Concrete International

Volúmen:

32

Número:

6

Periodo:

Junio 2010

ISSN:

01624075

SrcID:

01624075-2010-06.txt