Search for: [Abstract = "The distance between the levels of retaining walls should be based on the results of numerical modelling. The objective of this paper is to present a comparison between the data of numerical simulations and the results of the in\-situ lateral tests of couple piles. The problems have been solved by using the following soil models\: Coulomb\-Mohr model\; model, which is based on the dilatation theory\; elastic\-plastic model with variable stiffness parameters."]