ABSTRACT
Deformation of shoring walls used in cut-and-cover excavations in clayey soil is significantly reduced when the walls are constructed in improved ground and supported by preloaded braces. At the same time, earth pressure on the backside of the walls is greater than it would be if the above methods were not employed. In such cases, when developing a design method, it is no longer valid to assume that the earth pressure on the backside is a known value independent of wall displacement. The use of a calculation method that assumes a ground spring on the backside may be considered. This paper proposes a method to determine the horizontal subgrade reaction coefficient based on a numerical calculation using the finite element method. It also discusses the results of applying this proposition to two sites: one with ground improved on the excavation side and another where preloaded braces were used.
