Mathematical Models Calibration of Bridge-Type Structures by Means of Natural Period and Ambient Vibration

The analytical results of distinct sections of an 8 km length vehicular bridge located in Mexico City, which is based in a finite-element three-dimensional structural model, are compared to the obtained ambient vibration on-site results performed with triaxial accelerometers placed in strategic points along the bridge. The comparison includes the main natural vibration periods and dynamic properties. The soil in which the project is located covers different geotechnical zones (compressible, transition and bedrock) according to Mexico City's Construction regulations. The results obtained with the three-dimensional mathematical model are verified (calibrated) with the dynamic properties obtained from the ambient vibration tests. The main properties of the structural system are described, which include a reinforced concrete foundation, steel columns, a superstructure with steel girders and a reinforced concrete solid slab. Based on the on-site measurements and results, different recommendations are provided regarding conditions and criteria to be considered in the structural analysis execution performed with specific software for bridge-type structures.