In this paper a vibrational method for in situ investigations is described. The method has been applied to a bridge viaduct of about 800 m in length, with slender piers, a continuous deck and supports with a viscoelastic behavior. Three techniques of excitation of the structure have been utilized. The modes of vibration of the deck and the piers have been found with two techniques of excitation. The dynamic inputs for in situ tests have been produced by an artificial generator of vibrations (REM). The structural response has been measured with accelerometers. The spectral analysis of the environmental noise (wind) has been applied and the vibrational modes of the taller piers in the low frequency range have been determined. In this paper the bridge has been modeled with a finite element program and the dynamic behavior of the structure has been numerically determined. Then its vibrational modes have been compared with the ones experimentally obtained. The plots of the Power Spectral Densities (PSD) induced by the wind furnished more information on the vibration modes of the structure in the field of low frequencies. These information filled the lacks determined in this range performing the dynamic tests with the artificial generator of vibrations.
|Titolo:||Dynamic Control of Bridges with Slender Piers|
|Data di pubblicazione:||2008|
|Appare nelle tipologie:||1.1 Articolo in rivista|