ACCELERATION AMPLIFIED AND DE-AMPLIFIED RESPONSES WITHIN GEOSYNTHETIC-REINFORCED SOIL STRUCTURES

Physical data from various dynamic centrifuge modeling and shaking table tests on geosynthetic-reinforced soil (GRS) structures are compiled and used to evaluate the acceleration amplified and de-amplified responses within GRS structures. Analysis results show the horizontal acceleration (ah) inside GRS structures has a nonuniform distribution with height and varies with maximum input acceleration (amax). The variation and magnitude of acceleration amplification factor (Am), the ratio of ah to amax, decrease with the increasing amax. The horizontal acceleration inside GRS structures amplifies mostly at approximately amax<0.40g and attenuates at amax≥0.40g. The results also show the acceleration amplified and de-amplified responses are highly dependent on acceleration frequency f. The acceleration inside GRS structures amplifies considerably when the predominant and fundamental frequencies are close. Further, this paper examines the Am and amax relationships (i.e., Am=1.45- amax/g), proposed based on a series of finite element simulations and adopted in the current GRS structure design guidelines. The comparative results indicate Am and amax relationships adopted in the current design guidelines follow the lower bound of the physical data compiled in this paper, specifically for underestimate of Am at loweramax. The results obtained from this study provide insightful information for seismic design of GRS structures.