A new technique of strengthening soft soil under a strip footing by a granular trench reinforced with geogrid micro mesh

摘要

A series of 25 laboratory model tests was conducted to investigate the feasibility of using a granular trench reinforced randomly with Geogrid Micro Mesh (GMM) to achieve further soil improvement in terms of bearing capacity ratio and settlement reduction percentage as compared to the same trench systematically reinforced with layers of geogrid. The laboratory model was presented by a surface strip footing resting on reinforced and unreinforced granular trench (UGT) embedded in soft clay to simulate a plane strain condition. The effect of depth ratio (depth/width ratio of the trench) and reinforcement methods (randomly by GMM, systematically by layers and combination of these two methods) were considered. The results indicated that the depth ratio significantly increases the bearing capacity for both reinforced and unreinforced granular trench. Improvement in bearing capacity and settlement reduction increased gradually with increasing GMM percentage up to 1.2%. Beyond this value the strength tends to decrease. Further improvement can be obtained using a combination of these two methods of reinforcement. Such testing program on models reinforced by random GMM is not available in the literature.