MODAL ANALYSIS OF A CONCRETE GRAVITY DAM: EXPERIMENT, FINITE ELEMENT ANALYSIS AND LINK

摘要

Within the framework of EMPA research activities on experimental modal analysis applied to civil engineering structures the "Vieux Emosson" concrete gravity dam In the Canton Valats has been investigated in summer 1992. The aim of this project was firstly to gain experience with modal testing techniques applied to large dams. A randomly driven servohydraullc vibration generator was used as an exciter and the dam response was measured as acceleration at 53 points in three directions. Subsequently, the modal parameters such as natural frequencies, damping and mode shapes were determined. Secondly, an attempt was undertaken to update a Finite Element model of the structure taking the experimental results into account by using the Link-Procedures. The study shows that experimentally supported FE model optimization is possible with reasonable effort and good accuracy. The latter can be further Improved by taking the well known structure/soil/reservoir-interaction effects Into account.