Journal of the Korean Geosynthetics Society ISSN:2508-2876(Print) 2287-9528(Online) 한국지반신소재학회 논문집

Vegetated block retaining walls are constructed by stacking individual blocks and may therefore exhibit relative displacement and localized sliding along the block interfaces. However, conventional analyses often assume that the entire wall behaves as an integrated structure, which may result in inaccurate estimations of the resisting moment and wall displacement. In this study, the shear characteristics obtained from direct shear tests on block interfaces were incorporated into three-dimensional finite element models. The resisting moments and horizontal displacements obtained from an integrated model and an interface model were compared. The factors of safety against sliding for integrated and individual block behavior were also evaluated using the trial wedge method. For a 5m-high wall, the resisting moment calculated using the integrated model was 4.09 times greater at the top course and 1.49 times greater at the bottom course than that calculated using the interface model. The maximum top displacement of the interface model was 4.34 times that of the integrated model. For a 7m-high wall, the top displacement exceeded the allowable limit of H/200 by approximately 32.4%. The factor of safety for individual behavior under the block–block condition was approximately 0.86–0.93 times that for integrated behavior. In contrast, the block–pad–key–block condition increased the factor of safety to approximately 1.46–1.57 times that for integrated behavior. The shear connection elements improved the factor of safety by approximately 1.58–1.73 times compared with the block–block condition. The factor of safety increased as the wall slope became gentler; however, under a surcharge load of 10kPa, the block–block condition did not satisfy the required factor of safety of 1.5 at slopes steeper than or equal to 1:0.2. These results demonstrate that the shear characteristics of block interfaces, shear keys, wall slope, and surcharge load should be considered together for the rational stability evaluation of vegetated block retaining walls.