关键词: 加筋土挡墙, 土工格室, 模型试验, 变形, 格室应变

Abstract: For the advantages of light weight and high stability, the geocell-reinforced soil retaining walls will be widely used in the retaining construction in the near future. The performance of the facing-type geocell retaining wall reinforced by extending geocell layers with uniform spaces over the full height of the wall (FE-type), is better than other types of geocell retaining structures. However, the experimental researches on the FE-type geocell retaining walls are limited at present. The model test in this study was performed on an FE-type geocell retaining wall to examine the mechanical characteristics in terms of deformations and vertical stresses of the retaining wall under vertical static load. The strains of the extended geocell layers were examined and the effect mechanism was also discussed. Results show that the differential settlements of upper fillers of the retaining wall present as larger in the middle than that approaching the face-plate. The tuck net effect of the geocell layers inside the upper fillers owing to bending, and the strong lateral restriction of the geocell layers have transformed parts of vertical forces into the horizontal forces exerting on the geocell layer. Through the transformations of several geocell layers, the vertical stresses significantly decrease and the differential settlements almost disappear at the bottom of the retaining wall. Due to the warping deformation, the upper geocell layers exert downward tensions and inward contractions on the upper face-plates of the retaining wall. Consequently, the vertical displacements of the face-plates increase rapidly with increasing loads. And it also effectively limits the increasing of the horizontal displacements of the face-plate. The horizontal displacements of the face-plates ranging from 0.375H to 0.75H (where H is the height of the retaining wall) are larger than other parts, and the maximum displacement locates at the 0.375H height. The influences of the back filling height and loads on the distribution of the geocell layers strains along the horizontal direction are week. The potential failure surface of the FE-type geocell reinforced retaining wall resembles the curved shape that changes slowly along the vertical direction without penetrating the face-plates. The findings could provide valuable and practical references for the design and construction of the FE-type geocell-reinforced soil retaining wall.

Key words: reinforced-soil retaining wall, geocell, model test, deformation, strain of geocell layer