CONSTITUTIVE SOIL MODEL FOR EMBANKMENT OF RAILWAY FRAME BRIDGE

Abstract

This paper examines the suitability of three different soil constitutive models to assess soil movement in the embankment of a railway bridge. As population and traffic demand continue to increase, the implementation of underpasses for roads beneath existing railways has emerged as a viable solution for enhancing current transport infrastructure. The section where the road intersects with railway tracks can be accommodated by constructing a frame bridge. From a stability perspective, the abutments are the crucial locations that may affect the operation of the railway. Numerical analysis is a crucial tool for examining the safety of projects by adopting an appropriate soil constitutive model. This paper analyses the characteristics of commonly used constitutive models for earth bodies. It combines this analysis with actual engineering cases to assess the applicability of these models during the construction of the transition section between the road and bridge on both sides of the railway jacking frame bridge. Considering the elasticity, the plasticity of the soil, and stress changes during actual loading and unloading conditions, three different constitutive models, namely, Mohr-Coulomb, modified Mohr-Coulomb, and HSS Model, are compared and analyzed using the finite element software Midas GTS NX. The results indicate that the HSS model provides numerical results similar to the field monitoring data. Considering that the numerical analysis results showed a similar trend with the field monitoring data, this study establishes a baseline for selecting the constitutive model for the bridge abutments on both sides of the top-in-frame bridge of the railway business line.