The bridge over the Quisi Ravine in Alicante Province (Spain), built between 1913
and 1915, consists of six 22-22-42-42-22-22 m long steel Pratt truss spans, the lateral
spans being isostatic and the central spans continuous. All the joints between the steel
elements are riveted. As the bridge has been carrying railway traffic for more than 100
years, its condition needed to be assessed before carrying out the necessary repairs reinforcement to extend its service life. One of the most interesting tasks on the bridge
involved a study of its fatigue behaviour to estimate its remaining useful life. Only a few
kilometres away there happened to be another bridge with identical geometry over the
Ferrandet Ravine, which had recently been dismantled and taken out of service and had
carried the same railway traffic as the one over the Quisi Ravine. Advantage was therefore
taken of this unique opportunity to test one of its isostatic spans in order to extrapolate the
results to the Quisi Bridge. These tests were carried out at the ICITECH laboratories at the
Universitat Politècnica de València in two different scenarios: 1) one test on a 22 m span,
and 2) another on one of its girders, in both of which simulated railway traffic cyclical
loads were applied. The results allowed us to estimate the number of trains that could
pass over the bridge and its remaining service life, and also to define a monitoring
method to help in decision making in case of possible failures of its component parts.
The study also included an analysis of the bridge’s robustness in local failures of some
of its elements, which led to a further bridge cyclical loading test with a deliberately
damaged component. Even though other researchers had previously carried out fatigue
tests on full-scale riveted bridge elements, the ICITECH study is unique in that it is the
first time a full-scale bridge has been subjected to fatigue tests. This work was
accompanied by advanced numerical modelling studies considering the fracture
mechanics theory
