Characterization of the dynamic behavior of a concrete arch dam by means of forced vibration tests and numerical models

Abstract

The characterization of the dynamic behavior of an arch dam, and its evolution throughout the structure's lifetime, provides important data for the safety control process. Forced vibration tests remain a reliable technique for this purpose. The Baixo Sabor dam is a 123 m high arch dam recently built in Portugal. Forced vibration tests were performed before and after the reservoir filling.Two techniques for forced vibration test are compared, discrete frequency scanning, the standard methodology, and continuous frequency scanning (sine sweep), a new proposed methodology, which allowed faster results without loss of precision. For the interpretation of test results two numerical models of the dam-reservoir-foundation system were built, and calibrated with the experimental data. A good match of numerical and experimental results was obtained for the six lowest frequencies and corresponding mode shapes. K E Y W O R D Sconcrete arch dam, dam-water interaction, dynamic behavior, force vibration test, numerical models

Modelling Dam-Water Dynamic Interaction. Numerical Options and Experimental Validation

“…These authors also performed an application of this model to the case of a gravity dam in Japan, for which field records of earthquake response are available. Forced vibration tests were performed for the dynamic characterization of the dam, before the reservoir filling [7], and with full reservoir. The dam is equipped with a seismic monitoring system to evaluate the behavior of the structure when subjected to seismic actions.…”

“…A research project involving a recently built arch dam in Northern Portugal is providing extensive data on the dynamic behavior of the structure. In situ measurements of the dam dynamic response were made by two methods: forced vibration tests, performed before and after filling the reservoir, and a continuous monitoring system that has been installed in the structure [7,8]. In the present paper, the results obtained with the proposed numerical model are compared with these field measurements, providing a test of its practical performance under essentially linear conditions, given the relatively low levels of vibration induced.…”

Continuous Dynamic Monitoring Programs of Large Civil Infrastructures

“…The results obtained from this forced vibration test were later confronted with results obtained from a numerical model developed by LNEC. This model, based on discrete and finite elements, takes into account the dam's contraction joints, the deformability of the foundation and the reservoir [59]. To model the dam, 32 vertical blocks were discretized in isoparametric 20-node brick finite elements.…”

An RF-PCE Hybrid Surrogate Model for Sensitivity Analysis of Dams

“…Determination of the vibration characteristics in concrete dams (especially the unsymmetrical tall arch dams) is an essential task prior to perform any nonlinear seismic analysis [1], dynamic health monitoring [2,3], and system identification [4,5]. This research topic has received a lot of recognition in the past few years [6] and several advanced techniques have been developed such the one by Sevieri and De Falco [7] based on Bayesian interface model.…”