Numerical modelling of the reinforcing effect of geosynthetic material used in ballasted railway tracks

Abstract

This article deals with finite-element (FE) modelling of the reinforcing effect of the geosynthetic material used in the construction of a ballasted track. Various different designs of geosynthetic material are studied and their reinforcing effects are evaluated in terms of the total settlement reduction. Three-dimensional FE models of the reinforced railway superstructure are compared to a reference FE model with no reinforcement. Each geosynthetic material is modelled respecting its material properties, and the interaction with the ballast material is simulated according to its primary function. A clear distinction in the modelling of the interaction with the ballast material is made between geogrids and the remaining geosynthetics. A new approach to model the reinforcing effect of a geogrid is proposed and evaluated by FE analysis. The results of numerical modelling are compared to those of experiments conducted using an experimental box instrumented with one half of an instrumented concrete sleeper. Different types of geosynthetics were used to reinforce the ballast material, and the settlement reduction was measured using linear variable differential transformer (LVDT) sensors. The proposed FE models enable quick evaluation of the reinforcing effect of a given geosynthetic and comparison to other possible solutions in terms of the total settlement reduction. Other design possibilities (e.g. the use of reinforcing geosynthetics in several layers) are briefly discussed, too.

Stress-Strain Degradation Response of Railway Ballast Stabilized with Geosynthetics

“…Various types of geosynthetic reinforcements placed in unbound ballast have usually improved the performance of rail transportation systems, but unfortunately, the optimal location and number of geogrid layers have not been established. A few recent studies have attempted to analyze the effects of multiple geosynthetic reinforcement through model studies (Raymond and Ismail 2003;Jirousek et al 2010) and full-scale field trials (Montanelli and Recalcati 2003).…”

A comparative study of geosynthetically reinforced earth foundations in multi-utility transportation infrastructure for high-speed railways

“…The finite element model for reinforcement using geosynthetics from the experimental outputs were validated by Jiroušek et al (2010). There have been analytical models for the same in the literature (Rajesh et al, 2015).…”

Finite Element Modeling of Ballasted Rail Track Capturing Effects of Geosynthetic Inclusions

“…Previous laboratory studies (Bathurst and Raymond, 1987;Gobel and Weisemann, 1994;Raymond, 2002;Shin et al, 2002;Brown et al, 2007;Indraratna et al, 2011a) and field studies (Indraratna et al, 2010(Indraratna et al, , 2014a have demonstrated the successful application of geogrids in track reinforcement. Limited numerical simulations have been conducted to analyze the reinforcement mechanism of geogrids in railway tracks (Indraratna et al, 2007;Jirousek et al, 2010;Chen et al, 2012;Indraratna and Nimbalkar, 2013). The discrete element models are usually applied to capture the particle-scale mechanism and interface behavior using geosynthetics (Han et al, 2011;Tutumluer et al, 2012;Ngo et al, 2017;Gao and Meguid, 2018).…”