Water–structure interaction analysis of a segmental bridge using ambient vibration testing at different water levels

Abstract

Updating a finite-element (FE) model using dynamic parameters obtained from field testing requires an adequate understanding of the variation of such parameters due to changes in environmental conditions. This paper presents an experimental program to study the influence of the water–structure interaction in the dynamic response of a prestressed concrete segmental bridge with partially submerged piers in an artificial reservoir. The bridge, located in Colombia, has a total length of 558 m. Ambient Vibration Tests (AVTs) consisted of four experimental campaigns at different water levels to perform modal identification. In addition, existing empirical formulations accounted for the effect of the hydrodynamic masses concentrated in the piers. This paper shows that updating FE models from identified dynamic properties in partially submerged bridges involves percentage reductions in natural frequencies related to the reservoir's water level. Thus, providing a better insight into the incidence of water–structure interaction on partially submerged bridges' dynamic response. Finally, considerations during dynamic characterization tests are discussed.