Effectiveness of Using Shelves with Cantilever Retaining Walls

Cantilever retaining walls with pressure relief shelves are considered one special subset of retaining walls. The concept of providing pressure relief shelves towards the backfill side of a retaining wall reduces the total earth pressure on the wall, which results in reducing the thickness of the wall and ultimately to get an economic design. Limited solutions were presented for this type of walls in some research. This paper presents a set of finite element analyses for this type of wall using PLAXIS2D-AE. The reduction of the total active earth pressure due to provision of shelves has been studied. It was found that the shelves have a significant effect on the distribution of the earth pressure. It follows approximately the distribution of the Klein's, 1964, solution. A parametric study is conducted to discuss the effect of the number of shelves, shelf rigidity and shelf position on the resulted lateral earth pressure distribution, top wall movement and the maximum acting bending moment on the wall. For high retaining walls and some repairing systems of constructed walls having stability problems, it is much recommended to provide the cantilever wall by one shelf at one third of the wall height from wall top or more shelves at different levels.