Probabilistic structural analysis of São João Bridge based on the on‐site study of the time‐dependent behavior of concrete

Abstract

AbstractThis article aims to present a procedure to take into account the variability of the time‐dependent behavior of concrete on its structural effects, evaluated from the study of creep and shrinkage based on experimental data obtained on‐site. For this purpose, the São João Bridge, a railway bridge built in Porto, Portugal in 1991, is presented as a case study. São João Bridge is a railway bridge crossing the river Douro. It is a prestressed concrete structure, with a total length of 1,028 m, including the main span of 250 m, two side spans of 125 m, six approaching spans on the left river bank, and three approaching spans on the right river bank (Porto). During bridge construction, a comprehensive structural health monitoring (SHM) system was set up, as well as an on‐site study of time‐dependent behavior of concrete. This study was based on creep 15 specimens and 15 shrinkage specimens, prepared simultaneously with some segments of the deck, using the same material, and it was kept running during almost 20 years. The results of this study were treated statistically and used as random variables in a probabilistic analysis of the time‐dependent behavior of the bridge. After a brief description of the mentioned on‐site study and the bridge SHM system, the paper presents the procedure followed on the bridge numerical probabilistic analysis. Finally, the values computed by the numerical model are presented and compared with the experimental values provided by the SHM.