Failure analysis of widened railway embankment with different reinforcing measures under heavy axle loads: A comparative FEM study

• FE models for predicting stability of widened railway embankment were established. • Analysis of the effectiveness of various structural countermeasures is performed. • Relationship among safety factor, deformation and train load were established. • It is concluded that piled constructions demonstrates a better reinforcement effect. The widening of the railway roadbed for additional tracks is one of the effective ways to increase the carrying capacity of railway lines. However, the experience in using such railway sections shows that differences in the properties of soils and the degree of their compaction, as well as the effects of external force and climatic factors, greatly complicate the possibility of ensuring stable long-term joint operation of a new and old parts of the subgrade. This problem is especially acute with an increase in axle train loads associated with the transition from conventional to heavy traffic. In this work, we use the finite element method to perform a comparative analysis of the effectiveness of reinforcement of a widened railway embankment for heavy traffic by various structural countermeasures, including geosynthetics reinforcement, soil nailing techniques, and piled constructions. The purpose of the work is to establish the relationships between the reinforcement scheme, train load intensity, and the nature of embankments deformation, and to identify rational areas of their application. The regularities in the changes in the deformability of soils during reinforcement, as well as the changes in the stress gradient and the safety factor under axle loads from heavy trains are revealed. The mechanism of destruction of the slopes of the widened part of the embankment is investigated. Rational application domains of reinforcing structures for a widened railway embankment in terms of increasing the stability of its slopes and minimizing the deformability of the subgrade are determined.