Structural Health Monitoring of Offshore Platforms in the Persian Gulf Using "SIJacket" Computer Program for Ambient Vibration Tests

There existing platforms in the persian Gulf were selected and their ambient vibrations were recoded in several intervals. The platforms had been installed in a deep sector of Persian Gulf, with 67 meters water depth. The production platform was four legged steel jacket structure with six horizontal bracings in height and grouted piles. Penetration of piles, were equal to 60 meters. The Jacket had a boat-landing, tow oil risers which were connected to legs by clamps and a H2S riser from -24 meter to cellar deck. The platforms had a service life of 30 years at the time of vibration recordings (Fig. 1). A Procedure was developed to implement the Welch method for estimating the power Spectral Density function (PSD), by using the nonstationary algorithms. The emphasis was to illustrate the nonstationary signal processing for offshore structures and to implement a new method for higher resolution of PSD.

Keywords:

Damage detection system identification , SIJacket , offshore structure , steel jacket , spectral analysis , ambient vibration , nonstationary , nonlinear