Three-dimensional finite-element analysis of diaphragm wall installation

A series of finite-element analyses has been carried out to investigate the impact of three-dimensional effects and panel length on horizontal ground movements and changes in lateral stress during the sequential installation of number of diaphragm wall panels, The analyses show that the magnitude an d extent of lateral stress reduction in the vicinity of a diaphragm wall du ring construction depend on the panel length and are overpredicted in analy ses assuming conditions of plane strain, Furthermore, an overall increase i n lateral stress below the toe of the wall is calculated in a plane strain analysis, but is not evident following completion of the wall when a three- dimensional analysis modelling the sequential installation of a number of p anels is carried out. The analyses also show that three-dimensional effects tend to reduce lateral soil movements during installation of a diaphragm w all in panels compared with the plane strain case, but soil movements incre ase markedly with panel length at aspect ratios (panel depth:panel length) of less than three.