Impacts of Compaction Load and Procedure on Stress-Deformation Behaviors of a Soil Geosynthetic Composite (SGC) Mass—A Case Study

Abstract

Fill compaction in the construction of Geosynthetic Reinforced Soil (GRS) mass is typically performed by operating a vibratory or roller compactor, which in turns imposed a compaction load in direction perpendicular to the wall face. The compaction process resulted in the development of the so-called compaction-induced stress (CIS), which may subsequently increase the stiffness and strength of the fill material. Compaction process is normally simulated using one of the following compaction procedures—(i) a uniformly distributed load acting on the top surface of each soil lift, (ii) a uniformly distributed load acting on the top and bottom surface of each soil lift, and (iii) a moving strip load with different width. Uncertainties such as compaction procedures, compaction and surcharge loads led to the disparity in studying the mechanism of GRS mass. This paper aimed to study the impact of compaction load, compaction procedure, surcharge load and CIS on the stress-deformation behavior of GRS mass via the simulation of a 2 m high Soil Geosynthetic Composite (SGC) mass and a 6 m high GRS mass. The results were examined in terms of reinforcement strains, wall lateral displacements, and net CIS. Results from the analysis show the important impacts of compaction conditions on the stress-deformation behavior of SGC mass and the CIS.

Mechanical Responses of Soil-Geosynthetic Composite (SGC) Mass under Failure Load

“…Figure 2 depicts the typical geometry, loading condition, interface elements, and finite element mesh configured in the simulated SGC mass. The sensitivity of mesh sizes was examined, for examples, by Wu and Pham [4] and Gui et al [8]; the numerical results suggested that, to produce sufficiently accurate results, fine mesh without refinement should be chosen when performing simulation on the GRS problem. Thus, a fine mesh without refinement was used to discretize the model.…”

“…These experiments not only showed that the reinforcement spacing plays a more prominent role than the reinforcement strength but also revealed that the behavior of closely spaced reinforced soil can be designated as a nonhomogeneous GRS. Two-dimensional (2D) finite element (FE) analyses have also been performed by References [3][4][5][6][7][8][9] with the aim to appraise the composite behavior of the GRS mass experimented by Pham [3]. In particular, Pham [3] performed a number of finite element analyses and examined the effect of specimen sizes on the overall stress-strain and volumetric change distributions of the SGC mass with the aim to determine a generic dimension for the SGC mass that would produce a sufficiently close load-deformation behavior of a large GRS mass.…”

“…References [16][17][18][19][20][21][22][23][24] assessed the compaction effect by modeling the compaction load as a uniformly distributed load applied to the top surface of every newly placed fill as the wall was built from the base to the top, while Mirmoradi and Ehrlich [25][26][27] simulated the effect by applying the uniformly distributed load to the top and bottom surfaces of the fill layer. Gui et al [8] and Phan et al [9] conducted a series of numerical analyses on an SGC mass to evaluate the influence of compaction loads, compaction procedures, and surcharge loads on the response of the SGC mass. Gui et al [8] found that the compaction procedures and the compaction loads of 44 kPa and 70 kPa used throughout the construction of the SGC mass had negligible effect on the reinforcement strain and the lateral displacement of the wrapped-faces of the SGC mass.…”

“…Gui et al [8] and Phan et al [9] conducted a series of numerical analyses on an SGC mass to evaluate the influence of compaction loads, compaction procedures, and surcharge loads on the response of the SGC mass. Gui et al [8] found that the compaction procedures and the compaction loads of 44 kPa and 70 kPa used throughout the construction of the SGC mass had negligible effect on the reinforcement strain and the lateral displacement of the wrapped-faces of the SGC mass. However, their analyses were limited to the SGC mass with a reinforcement spacing of 0.2 m only; the compaction effect on SGC masses with different reinforcement spacings has yet to be validated.…”

Finite element analysis of compaction load to investigate the stress-deformation behavior of soil geosynthetic composite mass: A case study

“…The numerical methods have many advantages over laboratory experiments and field measurements, including obtaining more thorough results, examining the effects of various loading conditions, and researching the effects of various variables and parameters, which are challenging or expensive to achieve in laboratory and field tests. To assess the composite behavior of the GRS walls under static loading, two-dimensional (2D) numerical modeling studies have been carried out [26][27][28][36][37][38]44].…”