Influences of Geocell Reinforcement on Shear Strength of Railway Roadbeds

Abstract

The shear strength of geocell-reinforced railway roadbeds is influenced by diverse factors. This research aimed to explore the shear deformation performance of the geocell-reinforced railway roadbed under conditions of different reinforcement locations, confining pressures, and numbers of reinforced layers. To this end, large-scale undrained triaxial tests were conducted to measure the mechanical properties of a geocell-reinforced railway roadbed. The results show that geocell reinforcement plays a significant role in improving the peak deviatoric stress of the railway roadbed. The stress–strain relationship of the railway roadbed always exhibits strain-hardening characteristics, and the railway roadbed shows the optimal shear deformation resistance and strength when it is reinforced in its upper part. As the confining pressure increases, the shear strength and stiffness of the railway roadbed both increase while the secant modulus decreases with increasing axial strain. Meanwhile, the shear strength and strength coefficient of reinforcement of the railway roadbed both increase significantly with the increasing number of reinforced layers, along with large increases in the stiffness and energy absorption of the railway roadbed. The research results can provide a reference for the structural design of railway ballast layers to comprehensively control the stability and deformation of existing heavy railway roadbeds.