Curved concrete bridge girders have very complex internal forces, stress and strain distribution. As a consequence of
their shape, not only the usual bending moments and shear forces are generated, but also important torsion moments are
created. These moments "rotate" the axes of principal tensional stresses increasing the risk of cracking. Post-tensioning
can prevent the cracks, but the added compression forces introduced in different directions increase the complexity of
stress and strain fields. Therefore, the curved post-tensioned concrete girders must be particularly designed and carefully
constructed. However, the real structural behavior should be verified, and risks and uncertainties related to structural
design and quality of construction minimized. Structural health monitoring is a natural solution for these issues.
Structural health monitoring method, based on the use of fiber optic interferometric technology including long-gage
sensors and inclinometers, is presented in this paper. A 36 meters long curved post-tensioned bridge box girder is
equipped with so-called parallel and so-called crossed sensor topologies, and inclinometers, in order to monitor axial
strain, both horizontal and vertical curvature changes, torsion, average shear strain and rotations in both vertical plans.
Important parts of structure life such as construction, post-tensioning and first years of service are registered, analyzed