Experiments on Large Structures - Dynamic Behavior of Concrete and Seismic Engineering - page 230

As for the project previously described, the experimental results have been used
to develop and calibrate a finite element model of the same type as that shown in
Figure 6.21. The predictions of this model, in terms of the frequency response of the
acceleration on the crown, have been compared with test results for each measuring
position. The main objective of this project was to model the influence of water
level variation inside the reservoir on the dynamic response. For this structure, a
10% reduction of the dam stiffness simulated the opening of the joints in the dam
due to a decreasing hydrostatic pressure.
6.7. Conclusion
A numerical model is only valid if it can accurately represent the behavior of a
structure. Representing the dynamic behavior of a civil engineering structure is far
more difficult than representing its static behavior, and an engineer's experience is
required to determine the important parameters governing the response of the
structure. As far as dimensioning or verifying the safety of a large structure is
concerned, all the techniques presented in this chapter have been shown to constitute
reliable and economical methods to confirm the hypotheses used for the building up
of physical models. Furthermore, these techniques are at the root of new damage
prediction methods in which multiple tests are used to follow the behavior of a
structure over time.
6.8. Acknowledgements
The authors would like to acknowledge the support of the Civil Engineering and
Natural Science Research Committee in Canada, the Quebec Technology and Nature
Research Fund, as well as that of industrial partners who have contributed to the
different research projects on the dynamic behavior of large civil engineering
structures, notably the Ministry of Transport in Quebec, Hydro-Quebec, the Swiss
Water and Geology Federal Office, Electricité de France and Emosson S.A.
6.9. Bibliography
[AND 99] ANDERSEN P., BRINCKER R., PEETERS B., ROECK G. (DE), HERMANS L.,
KRÄMER C., “Comparison of System Identification Methods Using Ambient Bridge
Test Data”, 17 th International Modal Analysis Conference (IMAC) , Kissimee, Florida,
USA, pp. 1035-1041, 1999.