Nowadays there is a problem of the rail track structure reconstruction practice for the subgrade on weak foundation soils supply for 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 if the foundation soil is silty clay and peat soils. At the reinforcement of embankments by berms the value of stresses is reduced only by 15-20 percent. The increasing of the embankment height to decrease elastic settlements of the objects of the first group is simple and reliable method. But this method is difficult to provide because in this case it is necessary to reconstruct the contact network on the electrified lines. Subgrade and foundation in these cases follows the enlargement of the acerbity. The paper presents the results of the analysis, physical modeling and monitoring carried out 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 geomatrasses, 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.

weak foundation, physical modelling, light embankment, geodrains