|Software for Operational
Operational Modal Analysis of the Vasco da Gama Bridge
The results presented here were obtained by
performing a re-analysis with ARTeMIS Modal Pro of the database created
by Professors Alvaro Cunha and Elsa Caetano (Laboratory of Vibrations and
Structural Monitoring of the Faculty of Engineering of the University of
Porto, Portugal) during the dynamic tests performed on the Vasco da Gama
Bridge at the commissioning stage, under contract with Novaponte ACE
The Vasco da Gama bridge is located near Lisbon and is the second crossing
of the Tejo river. Three types of test were done: Ambient vibration test,
free vibration test and measurements in the stay cables. The results shown
below are based on the ambient vibration test. The equipment used were 6
triaxial GeoSIG seismographs synchronized by a portable PC.
In the table below the modes are presented. The mode has been estimated with
default settings of the Crystal Clear Stochastic Subspace
Identification estimator available in the ARTeMIS Modal Pro version.
Laboratory of Vibrations and Structural Monitoring
of FEUP VIBEST has their own web site at:
A detailed description of the test they did can be found in the following
Cunha Á., Caetano E. and Delgado, R.: "Dynamic
Tests on a Large Cable-Stayed Bridge. An Efficient Approach". Journal of
Bridge Engineering, ASCE, Vol. 6, No.1, pp.54-62, 2001.
Cunha Á., Caetano E., Brincker R., Andersen P.: "Identification from the
Natural Response of Vasco da Gama Bridge", 22nd International Modal Analysis
Conference (IMAC), Dearborn, Michigan, 2004.
Pictures from the Test
The Vasco da Gama bridge in its full length, seen
from northern edge of the Tejo (Tagus) river:
The main span consist of a cable stayed bridge:
The main span seen from the northern edge of the
The main span seen from the southern edge of the
The bridge during construction: