Abstract: The corner effect has a significant effect on the deformation of the supporting system for the rectangular shaped deep excavation sites. The critical aspect ratio of the excavation site and the corner effect on the deformation influence zone are studied by 3 dimensional finite element analyses.  The deformations of various dimensions of supporting systems are also numerically analyzed. The results indicate when the aspect ratio of a rectangular excavation is greater than the critical aspect ratio, the deformation distribution pattern, earth pressures on the supporting structures, and the magnitude of heaves at the bottom of the excavation, are approaching to the constant values and will not change with the variation of the aspect ratio. The corner effect limits the deformation of the supporting system.

Key words: Deep Excavations, Scale Effect, Three-dimensional FEM, Critical aspect ratio