Determination of clay stiffness with finite element method for ground movement prediction of soil-cement column wall and pile wall reinforced with soil-cement column used in deep excavation

Abstract

This paper presents research work on studying behavior of earth retaining system for deep excavation and determines appropriate stiffness of clay for prediction of wall movement using finite element method. Four types of retaining wall constructed in the same subsoil profiles are used in the studies i.e. contiguous pile wall (PW), soil-cement column wall (SCCW), and pile wall reinforced with soil-cement column (SCC). The behavior of wall is observed by measurement of wall movements and strut load at various stages of excavation and used for back-analysis with 2D and 3D finite element. The stiffness of clay in term of Eu/Su is 750 – 1250 for PW reinforced with SCC and 750-2000 for SCCW. The stiffnesses of clay is inversely proportional to the approximated shear strain from measured wall movement increase. The calculated strut forces agree well with the forces measured from the field.