INVERSE IDENTIFICATION OF DAM-RESERVOIR INTERACTION INCLUDING THE EFFECT OF RESERVOIR BOTTOM ABSORPTION

In this paper, a procedure is developed which can be used to identify the natural frequencies and natural modes in vacuum of an Arch-Dam from forced vibration testing data of partially filled reservoir. The effect of hydrodynamic pressure is removed by using an efficient algorithm. To verify the procedure, a simple structure is substituted for the dam with known properties in vacuum. Then a thin SSSF-plate is considered as the retaining wall representing of the dam and a sub-structuring technique is used with regard to a three dimensional linear compressible inviscid fluid body. The calculated resonance in the illustrated example replaces the resonance which in practical in-situ has been measured. Also the effect of the wave absorption at the bottom and bank of the reservoir is considered. The hydrodynamic pressure of the reservoir is calculated using boundary element method. The results which derived by solving an inverse problem, are compared with the exact analytical responses of the plate.