Comparative Analysis of Numerical Simulation Methods for Active Earth Pressure on Rigid Retaining Walls

There are significant advantages in analysing lateral earth pressure on retaining walls using numerical simulation methods because soil deformation behaviours can be fully involved in the methods. Operational processes as well as advantages and disadvantages of five typical numerical approaches are generally summarized and analysed, including wall active displacement method, wall elastic modulus reduction method, soil weight increase method, wall bottom friction coefficient reduction method and wall weight reduction method. Taking a wall translation mode as a typical example, the numerical analysis of each method is carried out via FLAC3D. The results show that distribution curves of active earth pressure along the height of wall exhibit a parabolic mode with the peak close to the wall bottom. The slip surface in the retained soil is curved, in contrast to the plane mode in the classical theories. The difference of the resultant force of the earth pressure between these numerical methods and the Coulomb theory is about 0.3–7.2%. In the condition that the retained soil reaches the active limit state, the computed wall displacements are about 1.2–2.4‰ of the wall height and they are very close to the test values. The rationality of computation principle, feasibility of simulating wall motion mode, applicability of simulation results and calculation efficiency of the five numerical methods are comprehensively compared, which indicates the calculation principle of the latter two methods is more reasonable than that of the first three methods. It is accordingly suggested to give priority to the wall weight reduction method, which can be followed by the bottom friction coefficient reduction method. The former can present the translational and rotational movement modes of the wall, but the latter can only be used in the translational mode.