Influence of reinforcement-arrangements on dynamic response of geogrid-reinforced foundation under repeated loading

摘要

Dynamic tests were carried out on a square footing resting on unreinforced and reinforced foundation to investigate the influence of the geogrid-reinforcement arrangements on load-carrying characteristics of the footing under repeated loading. In this paper, the arrangements considered include the depth of the first geogrid layer (u), the number of geogrid layers (N) and the method of wraparound ends reinforcement. The settlement of footing, the strain of geogrid and the acceleration rate in soils were measured, and these results were analyzed in detail. The results showed that the bearing capacity of footing on reinforced foundations was at least 12% higher than that of unreinforced foundation. For the single-layer reinforced foundations, the bearing capacity first increased and then decreased with the increase of u. When u was equal to 0.6B (B = footing width), the bearing capacity was maximum, which was 21% and 15% higher than that of 0.3B and 0.9B, respectively. For the multi-layer reinforced foundations, the bearing capacity increased with increasing the N value from 1 to 3, and the maximum increase was 29%. Through analyzing the bearing capacity ratio (BCR) and the attenuation rate of acceleration (AAR), the influence of reinforcement arrangements on the bearing capacity of footing was in the order: the u value, the method of wraparound ends of reinforcement, the N value. The various reinforcement arrangements caused different dynamic responses, and the sensitivity of arrangement on acceleration responses was in the order: the N value, the method of wraparound ends of reinforcement and the u value. Additionally, it is also found that reinforcement arrangements significantly affected the geogrid strain and the failure mode of footing. (C) 2020 Elsevier Ltd. All rights reserved.