Seismic Damage Behavior Of A High Concrete Gravity Dam

A 203-m high concrete gravity dam is a huge structure the safety and stability of which need to be investigated seriously. The present dissertation is the fruit of the experimental work on the above-said concrete gravity dam. In this document two sets of experiments were carried out on the scaled models and the seismic performance of the dam was studied.Firstly it presents the dynamic characteristics, the seismic responses and the failure mode of the previous structure. Three models of dam have been tested using the shaking table of the Earthquake Engineering Research Institute under the School of Hydraulic Engineering at Dalian University of Technology to simulate the earthquake effects. Two of the models were subjected to the Chinese Seismic Code Wave while the third one was with Lijiang Wave, a natural wave. The location and the length of the cracks at the end of the experiments showed that different seismic waves produce different damage behavior.Secondly, the damage behavior of the structure was studied by using the electro-mechanical-based smart aggregates. The purpose was to evaluate the damage of a scale model of a high concrete gravity dam during and after an earthquake. To detect the damage in the scale model, a built-in smart aggregates (SAs) were used in the scale model of a high concrete gravity dam. The electro-mechanical Impedances (EMIs) of SAs were measured for different experimental cases. The variations in the impedance spectral of the SAs were extracted as the damage-sensitive features. In this study, PZT were embedded in concrete to form a small cylinder, which we call smart aggregates. Then the smart aggregates were placed in the scale model, and the impedance/admittance signatures were measured by the impedance analyzer. The root mean square deviation (RMSD) of the impedance and admittance signatures was statistically calculated to detect the damage. The results demonstrate that the EMI-based SAs can effectively detect the seismic damage in the scale model, which shows the potential application to the structural health monitoring for high concrete gravity dam.