Properties of Shredded Roof Membrane–Sand Mixture and Its Application as Retaining Wall Backfill under Static and Earthquake Loads

Livingston, Bennett; Ravichandran, Nadarajah

doi:10.3390/recycling2020008

Cited by 11 publications

(3 citation statements)

References 14 publications

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“…The effect of rubber content on the friction angle has also been investigated. Livingston and Ravichandran [51] reported that the friction angle of the mixture increases with an increase in rubber content. In contrast, Lee et al [46] found that the friction angle of the mixture decreases with an increase in rubber content.…”

Section: Introductionmentioning

confidence: 99%

Sand–Tire Shred Mixture Performance in Controlling Surface Explosion Hazards That Affect Underground Structures

et al. 2021

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Blasting is an unavoidable activity in geotechnical engineering, road and tunnel construction, and mining and quarrying. However, this activity can expose the environment to various hazards that are challenging to control and, at the same time, critical for the safety of site workers, equipment, and surrounding structures. This research aims to evaluate the ability of sand–tire shred mixtures to reduce peak blast pressure, which is the leading cause of damage to underground structures under surface explosion. ABAQUS software is used to model the material behavior under explosion and is validated using the results of previous studies and an empirical equation. Different scenarios are created by using mixture layers with different thicknesses (2, 4, and 6 m) and tire shred contents (10%, 20%, and 30%) that are subjected to various surface explosion charges (100, 500, 1000, and 5000 kg). The thickness of the mixture layer is found to be directly related to the dissipation of explosion energy. However, the percentage of the rubber content in the mixture is only significant in reducing peak blast pressure when a thick enough mixture layer is used. The results confirm the adequate performance of the correctly chosen sand–tire shred mixtures in reducing peak blast pressure and protecting the underground structure from surface explosion hazards.

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Section: Introductionmentioning

confidence: 99%

Sand–Tire Shred Mixture Performance in Controlling Surface Explosion Hazards That Affect Underground Structures

et al. 2021

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“…In most of the mentioned studies, it is concluded that up to a specific scrap rubber percentage, the higher the percentage of tire shreds or tire chips, the greater the shear strength [39]. While a few studies have concluded that the effects of granulated rubber on mixture behavior are similar to tire shreds and tire chips [40], many others have reported results showing the opposite [41]. In all types of scrap rubbers, however, by increasing aspect ratio and/or confining pressure, the shear strength has increased [41].…”

Section: Introductionmentioning

confidence: 99%

Influence of Initial Anisotropy, Stress Path and Principal Stress Rotation on Monotonic Behavior of Clean and Mixed Sands

Fakharian

Hamedani

2020

KEM

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It is widely accepted that soil behavior is complicated taking into account soil anisotropy owing to the fact that this phenomenon arises from oriented soil fabric or structure forged in the deposition stage. In this study, a review of major findings of authors’ previous studies are presented with the main focus on soil anisotropy using extensive experimental results incuding Triaxial (TXT), Simple Shear (SSA), and Hollow Cylinder (HCA) apparatus. Effects of initial anisotropy, fabric evolution, stress path, principal stress rotation and intermediate stress state are evaluated for a crushed silica sand. In addition, the effects of Portland cement content and granulated rubber contents on anisotropic behavior of the sand are investigated. Bender elments are mounted on triaxial specimens both in vertical and horizontal directions to measure the shear wave velocity and hence maximum shear modulus at the end of consolidation as well as during shearing up to large strains at critical state condition, as an index of evaluating the fabric evolution. The effects of principal stress rotation and stress paths reveals the crucial role of soil anisotropy on the behavior of clean sand. However, adding either cement or granulated rubber to the sand has considerably decreased anisotropy.

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“…Granular filling materials are commonly placed inside confining structures for various engineering purposes; such applications include but are not limited to silos, trenches, mine stopes, and backfill retaining walls [1][2][3][4][5][6][7][8][9][10][11]. Upon placement, the fills settle downward due to self-weight, whereas the stiff confining walls tend to keep fills by limiting vertical displacements.…”

Section: Introductionmentioning

confidence: 99%

Theoretical and Numerical Analyses of Earth Pressure Coefficient along the Centerline of Vertical Openings with Granular Fills

Yang

Aubertin

2018

Applied Sciences

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Granular filling materials are placed into confining structures for various purposes, including but not limited to silos, trenches, mine stopes, and retaining walls for backfill. Stresses in these backfilled openings are commonly estimated using theoretical arching models, with equations that often involve the earth pressure coefficient K (=σ’h/σ’v). Such stress estimation can be dramatically impacted by the magnitude of K, but its value remains debatable. Along the centerline of vertical openings with granular cohesionless fills, the value of K is sometimes obtained by Jaky’s earth pressure coefficient at rest K0, based on the assumption of fixed confining walls, whereas Rankine’s active earth pressure coefficient Ka is regarded more suitable for K as claimed by some others. Recent numerical analyses from the authors have shown that the state of stress close to the center of backfilled openings cannot be solely related to wall movement. It was also shown that the K value can vary between Ka and K0 in backfilled openings with fixed (immobile) walls, depending on the locations and respective values of fill internal friction angle ϕ’ and Poisson’s ratio ν. However, none of the existing works have addressed the mechanisms and answered this fundamental but critical question: which value of coefficient K (K0, Ka, or other) should be used with analytical solutions to assess the stresses in backfilled openings (and why)? After assessing the state of the fill placed in a confined opening, theoretical relationships and specific mechanisms are proposed, for the first time, to evaluate critical values of ν and ϕ’ for defining the at-rest and active states in fills. The approach indicates that when ν or ϕ’ are smaller than or equal to critical values, the value of K near the center line of a backfill opening should be close to Ka; otherwise, K tends to approach K0 defined from ν. The theoretical analysis is complemented and validated (in part) by numerical simulations. The results also demonstrate that Poisson’s ratio can play a major role on the stress distribution within cohesionless fills, and should thus be accurately evaluated.

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Properties of Shredded Roof Membrane–Sand Mixture and Its Application as Retaining Wall Backfill under Static and Earthquake Loads

Cited by 11 publications

References 14 publications

Sand–Tire Shred Mixture Performance in Controlling Surface Explosion Hazards That Affect Underground Structures

Sand–Tire Shred Mixture Performance in Controlling Surface Explosion Hazards That Affect Underground Structures

Influence of Initial Anisotropy, Stress Path and Principal Stress Rotation on Monotonic Behavior of Clean and Mixed Sands

Theoretical and Numerical Analyses of Earth Pressure Coefficient along the Centerline of Vertical Openings with Granular Fills

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