摘要(英) |
For the backfill materials of the geosynthetic reinforced earth walls (GREWs), the design and construction guidelines usually require the use of high quality granular. In practice, nevertheless, the cohesive soil or clay is frequently used to cut down the cost. Over the past years, centrifuge modeling technique has been adopted to investigate the effect of cohesive soil on the deformation of GREWs, where either the kaolin or the laterite was chosen as the backfill. However, even under the category of clayey soil, different kinds of clayey soil exhibit different mechanical properties which may affect the wall behavior significantly. Therefore, in this study, a series of centrifuge modeling tests was performed to investigate the deformation of the vertical geosynthetic reinforced earth wall (VGREW) with low strength kaolin backfill and the improvement on the wall deformation was also studied by using the different arrangement of reinforcement. The obtained results were then compared with those using laterite as backfill.
From the test results, conclusions can be drawn as follows. (1) The secant modulus, E50, of the cohesive backfill is the most important factor to influence the deformation of VGREWs, implying that the in-situ soil should be used as the backfill to simulate the wall behaviors. (2) It is more effective to reduce the settlement and the horizontal displacement of VGREW by decreasing reinforcement spacing with better effect being for laterite backfill than for kaolin backfill. (3) From the deformation point of view, the deformed shape of wall face changes form bulging to tilting when the reinforcement spacing is decreased. (4) For two types of backfill soil compared in this study, with the same arrangement of reinforcement, the positions of the crack on the wall top are identical, while the timing for crack occurrence is totally different. |
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