Abstract: Reinforcing the zone near the crest using geo-grid is one of the seismic engineering measures for earth core rockfill dams. However, there lacks experimental study on the seismic response of the reinforced dams. In order to assess the performance of geo-grid reinforcement, a series of centrifuge dynamic tests was performed using the IWHR (China Institute of Water Resources and Hydropower Research) horizontal-vertical shaker. The influence of the vertical spacing between geo-grid layers and the stiffness of geo-grid materials on the seismic response has been investigated. The results of the dynamic centrifuge tests indicate that the stiffness has been increased in the zone near dam crest by geo-grid reinforcement. This leads to stronger seismic response in both upstream-downstream and vertical directions. In addition, the seismic resistance of the dam can be increased by placing geo-grid in a spacing of 0.08H~0.16H. Moreover, the stiffness of the geo-grid has a strong influence on the seismic resistance. If the geo-grid is too strong, the coupling between geo-grid and soil cannot be maintained, and thas the performance of geo-grid reinforcement cannot be satisfying.

Keywords： dynamic centrifugal model test； geo-grid； earth core rockfill dam； seismic response； seismic measure

(Journal of China Institute of Water Resources and Hydropower Research, Vol. 16, No. 6, 2018)