Evaluating the Role of Geofoam Properties in Reducing Lateral Loads on Retaining Walls: A Numerical Study

Abstract

Expanded polystyrene (EPS) geofoam is a lightweight compressible material that has been widely used in various civil engineering projects. One interesting application of EPS in geotechnical engineering is to reduce the lateral earth pressure on rigid non-yielding retaining walls. The compressible nature of the EPS geofoam allows for the shear strength of the backfill soil to be mobilized, which leads to a reduction in lateral earth pressure acting on the wall. In this study, a finite element model is developed and used to investigate the role of geofoam inclusion between a rigid retaining wall and the backfill material on the earth pressure transferred to the wall structure. The developed model was first calibrated using experimental data. Then, a parametric study was conducted to investigate the effect of EPS geofoam density, relative thickness with respect to the wall height, and the frictional angle of backfill soil on the effectiveness of this technique in reducing lateral earth pressure. Results showed that low-density EPS geofoam inclusion provides the best performance, particularly when coupled with backfill of low friction angle. The proposed modeling approach has shown to be efficient in solving this class of problems and can be used to model similar soil-geofoam-structure interaction problems.

Numerical Modelling of Soft Soil Improvement Using Expanded Polystyrene Geofoam for Road Embankment

“…Table 1 shows the soil parameters obtained from Chik et al (2013) from the East Coast Expressway project, while Table 2 shows the parameters of reinforced material using geotextile material obtained from Mamat et al (2021). In addition, table 3 shows the EPS parameter used in the FEM analysis obtained from Khan & Meguid (2021).…”

Enhancing retaining wall stability with geofoam

“…Arellano et al [ 7 ] also delve into the use of geofoam beads as lightweight fill materials, highlighting their effectiveness in reducing lateral stress and enhancing the seismic response of soil structures. Additionally, the static applications of geofoam are crucially highlighted in studies like that of Imran Khan and Meguid [ 8 ], which demonstrate how geofoam properties can significantly reduce lateral loads on retaining walls, thereby emphasizing the relevance of these applications to my focus on static load reduction [ 9 ].…”

Optimum Orientation of Geofoam Inclusion in the Retaining Wall

“…There are many studies on geofoam including retaining walls (Elragi 2000 [1], Zarnani and Bathurst (2008) [2], Zarnani and Bathurst (2009) [3], Dasaka et al, (2014) [4], Abdelsalam and Azzam (2016) [6], Sayed et al, (2020) [8], Xie et al, 2020 [7]). Some of the studies had dealt with the numerical modelling of the geofoam inclusion non-yielding walls (Zarnani and Bathurst (2008) [2], Zarnani and Bathurst (2009) [3], Abdelsalam and Azzam (2016), Sayed et al, (2020) [8], Khan and Meguid (2019) [9]. Elragi (2000) [1] gave the detailed overview of the engineering properties and engineering applications of geofoam.…”

“…The study also examined the application of geofoam in the yielding walls and found the minimum thickness of geofoam for the effective reduction of the lateral pressures. Parametric studies like geofoam thickness and geofoam density were carried out to examine the lateral pressures on the retaining walls (Sayed et al 2020 [8], Khan and Meguid (2021) [9]. Khan and Meguid (2021) [9]) studied the lateral pressures at the retaining wall with various internal friction angle values of the backfill and various densities of the geofoam materials.…”