Performance of the 8.7-km Bridge Spanning Lake Maracaibo in Venezuela

Abstract

The bridge spanning Lake Maracaibo in Venezuela, also known as General Rafael Urdaneta Bridge, opened to traffic in 1962 and is frequently referred to as the first modern cable-stayed bridge with multiple spans. The structure extends over 8.7 km (5.4 mi), features six cable-stayed spans, five 235-m-long (771 ft) navigation channels, and was designed by Riccardo Morandi. The remaining spans are formed by a series of piers at variable spacing ranging from 36 to 85 m (118 to 279 ft), which receive simply supported precast prestressed girders. In February 2010, it was found that the support for one prestressed girder had failed and the beam was hanging from the end diaphragm at Pier 27. This paper presents a description of this failure, the replacement of the original supports by pot bearings in combination with flat jacks, and the use of the upper-bound and lower-bound theorems of plasticity to design the retrofitting scheme. The paper also includes a description of the structure and its performance in nearly 60 years of service, the highly corrosive environment of Lake Maracaibo, replacement of the main cable stays in 1980, and a brief comparison with the bridge in Genoa, Italy, that partially collapsed recently, also designed by Morandi.