A study of geogrid-reinforced ballast using laboratory pull-out tests and discrete element modelling

Abstract

This paper presents an evaluation of the behaviour of geogrid-reinforced railway ballast. Experimental large box pull-out tests were conducted to examine the key parameters influencing the interaction between ballast and the geogrid. The experimental results demonstrated that the triaxial geogrid outperforms the biaxial geogrid and the geogrid aperture size is more influential than rib profile and junction profile. The discrete element method (DEM) has then been used to model the interaction between ballast and geogrid by simulating large box pull-out tests and comparing with experimental results. The DEM simulation results have been shown to provide good predictions of the pull-out resistance and reveal the distribution of contact forces in the geogrid-reinforced ballast system. Therefore, the calibrated geogrid model and the use of clumps to model ballast particles hold much promise for investigating the interaction between geogrids and ballast and therefore optimising performance.

Experimental and numerical studies of the performance of the new reinforcement system under pull-out conditions

“…These parameters might be affected by several factors: for example, the physical and mechanical features of the soil, the geometry of the reinforcement, boundary conditions, the experiment equipment, and overburden pressure. Many researchers have studied the effects of various parameters on friction resistance between soil and reinforcement, through numerical and experimental approaches (Jewell et al, 1984;Milligan and Palmeira, 1987;Bergado et al, 1993;Alfaro et al, 1995;Perkins and Edens, 2003;Alfaro and Pathak, 2005;Sieira et al, 2009;Hsieh et al, 2011;Esfandiari and Selamat, 2012;Hussein and Meguid, 2013;Chen and McDowell, 2013;Shi and Wang, 2013;Balunaini et al, 2014;Chen et al, 2014;Esmaili et al, 2014;Hatami and Esmaili, 2015).…”

Flexural Performance and Toughness Characteristics of Geogrid-Reinforced Pervious Concrete with Different Aggregate Sizes

“…Geogrid has been playing an important role in solving geotechnical problems due to its high strength and elongation ratio [ 10 , 11 , 12 , 13 , 14 ]. In pavement applications, geogrid is commonly used to provide safety for traffic and increase the service life of roads.…”

DEM-FDM Coupled Numerical Study on the Reinforcement of Biaxial and Triaxial Geogrid Using Pullout Test

“…Through analyzing the contact between the particles and the bonded particles in the geogrid, the discrete element method can well simulate the interaction between the geogrid and the surrounding soil. Although the microscopic parameters of geogrids composed of bonded particles can be obtained through a series of index calibration tests [17,18], it is difficult to intuitively show stress-strain characteristics similar to those of a real geogrid, which makes it difficult to capture the real deformation characteristics of the geogrid in pullout simulations. To combine the advantages of these continuous and discontinuous methods, the discrete/continuous coupled numerical method can be used to simulate the interaction between the geogrid and the surrounding soil.…”