DEM analysis of geobag wall system filled with recycled concrete aggregate

• Published in: Construction & building materials 2020-03, Vol.238 (C), p.117684, Article 117684
• Main Authors: Wu, Jiujiang, El Naggar, M. Hesham, Li, Xiaonan, Wen, Hua
• Format: Article
• Language: English
• Subjects: DEM analysis; Geobag wall system; Model test; Parameter calibration; Recycled concrete aggregate
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2019.117684

•Geobag wall system provides a novel way to deal with recycled concrete aggregate.•The study is both numerical and experimental.•The overall deformation of the geobag wall system appears to be a flexible mode.•The results provide more insights into the DEM modeling of geobag wall systems. This paper investigates numerically a novel geobag wall system using recycled concrete aggregate. The analysis of the performance of the geobag wall system as a flexible retaining wall to support an embankment was conducted employing the discrete element method (DEM) code PFC2D. The slope soil was simulated as bonded balls utilizing the contact-bond model, and the recycled concrete aggregate was treated as unbonded balls based on the linear contact stiffness model. The geotextile of the geobags was set as ball clusters with the parallel bond model. The corresponding parameters of the slope soil, aggregate, and geotextile were derived from biaxial tests, large-scale direct shearing tests, tensile tests, and modified shearing tests. These parameters were calibrated by contrasting the measured data with the numerical results. Utilizing the calibrated parameters, numerical models were established for slopes strengthened by the geobag wall systems, which had been investigated in a series of experimental indoor 1-g model tests. The numerical results were contrasted with the measured data in terms of settlement, horizontal displacement, soil pressure, and crack distribution. Additionally, the coordination numbers, porosities and displacement vectors of the DEM models were also investigated. The modeling methods and results presented in this paper can provide researchers with more insights into the DEM modeling of geobag wall systems and recycled concrete aggregate.