ABSTRACT
Nowadays in the Russian Federation there is a problem of the construction and exploitation of the subgrade on the weak foundation, including the efficiency assessing of subgrade stability assessing methods on the weak silty soils. Especially this problem has a significant importance in the northwestern part of Russia where the foundation soil is silty clay. The paper presents the results of physical modelling and monitoring carried out by the Russian Railway Universities of Moscow and Saint-Petersburg to assess the efficiency of several methods to reinforce the embankments foundation. There is the evaluation of the performance models for the foundation reinforce by geomattresses, filled with stone material. The simulation results showed that the embankment reinforced with geotextile has significant uniform precipitation, which can later lead to bulging of the underlying subsoil outside the contour of the slopes. The optimal solution in this case is the lightweight embankments with a core of expanded polystyrene (foam). This solution is effective to reduce the total embankment deformations on soft soils and to limit the lateral displacement.
