Resumen

GODHO RAMIREZ, Gustavo Adolfo; RIVERA-VARGAS, Darío  y  RAMIREZ GUZMAN, Leonardo. Seismic response measured of an urban bridge located on soft ground. Ing. sísm [online]. 2024, n.113, pp.81-114.  Epub 07-Mar-2025. ISSN 0185-092X.  https://doi.org/10.18867/ris.113.666.

Given the increase in vehicular traffic in the metropolitan area of the Valley of Mexico, the construction of bridges has been resorted to in places with soft soil, with highly compressible clays, which give rise to a significant amplification in the excitation of the soil. This situation generates uncertainties in the seismic performance of the bridges located in these sites, so it is convenient to monitor their dynamic response in order to improve the criteria for their seismic analysis and design. This paper presents the analysis of the seismic response of the Impulsora Vehicular Bridge, located in soft ground, based on the processing and interpretation of the seismic records derived from the instrumentation of the structure, during the monitoring period 2004 to 2017. From this analysis, the main vibration periods and the damping of the structure were obtained, with which an analytical model was calibrated and its seismic safety review was carried out. It was found that when it comes to a bridge, whose fundamental vibration period is less than 0.5 s, located on a soft ground with a site period of 4.25 s, the seismic risk condition to which it is exposed is low. Consequently, it has a large safety factor, which shows that the bridge was designed with a spectral acceleration higher than that which will actually be demanded, which is attributed in part to the uncertainty in the estimation of the seismic intensity. In addition to the above, the drift demands that the resisting frames of this bridge experienced during the September 19, 2017 earthquake, gave rise to a satisfactory level of full operation performance, which is desirable in this type of works, given its importance.

Palabras llave : Urban bridge; seismic records; seismic response measured; vibrations period; damping.

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