scholarly journals Investigation on Parameter Calibration Method and Mechanical Properties of Root-Reinforced Soil by DEM

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Hao Bai ◽  
Ruidong Li ◽  
Wubin Wang ◽  
Kang Xie ◽  
Xiang Wang
Keyword(s):  
Laboratory Tests ◽  
Calibration Method ◽  
Reinforced Soil ◽  
Reinforcement Effect ◽  
Parameter Calibration ◽  
Shear Tests ◽  
Root Characteristics ◽  
Soil System ◽  
Root Reinforcement ◽  
Direct Shear Tests

The behavior of root-soil system has raised more and more attention in both ecological and geotechnical fields. In this study, a two-dimensional discrete element method is employed using PFC2D to simulate the root-reinforced soil. The root system is mimicked by chains of bonded discs, while the soil is modeled by granular particles. The tensile strength of the root is modeled by interdiscs’ bonding strength. Three laboratory tests were studied to calibrate the micromechanical parameters of DEM. Finally, direct shear tests on rooted soil are simulated to investigate the influence of different root characteristics on the root reinforcement effect.

Waste Paper Application in Geotechnical Project

2012 ◽  
Vol 535-537 ◽  
pp. 2148-2153
Author(s):  
Amin Chegenizadeh ◽  
Hamid Nikraz
Keyword(s):  
Shear Stress ◽  
Kaolin Clay ◽  
Direct Shear ◽  
Reinforcement Effect ◽  
Embankment Dam ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Reinforcement Content ◽  
Strength Behavior ◽  
Clay Kaolin

Composite soils have been widely used in civil engineering applications, especially in slopes, embankment dam and landfills. This paper aims to investigate effect of fiber inclusion on shear stress of composite soil (i.e. clay composite). A series of laboratory direct shear tests carried out to evaluate paper reinforcement effect on strength behavior of composite clay. Kaolin clay was selected as soil part of the composite and paper was used as reinforcement. The paper reinforcement parameters differed from one test to another, the paper length was changed from 10 mm to 30 mm and paper content were varied from 5% to 15%. Normal stress kept constant at 150 kPa. For each test, stress_ displacement graph derived and the results were compared. The results proved that inclusion of paper reinforcement affected strength behaviour of clay composite so that increasing in paper reinforcement content and length caused increasing in shear stress.

Micromechanical analysis of loop-formed fiber-reinforced soil composite

2013 ◽  
Vol 44 (3) ◽  
pp. 418-433
Author(s):  
Seyed Mahdi Hejazi ◽  
Seyed Mahdi Abtahi ◽  
Mohammad Sheikhzadeh ◽  
Amir Mostashfi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Reinforced Soil ◽  
Soil Reinforcement ◽  
Fiber Reinforced ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Proposed Model ◽  
Fiber Reinforced Soil ◽  
Element Method

In this research, loop-formed fiber is introduced as a novel reinforcement method of soil composites instead of using ordinary fibers. In order to investigate the materials' mechanical properties, the shear behavior of both fiber and looped-fiber-reinforced soil composites was analyzed by micromechanical method (finite element method) and a set of direct shear tests. The results indicate that the looped-fiber soil composite exhibits greater failure strain energy compared with fiber-reinforced soil composite at the same fiber orientation in the substrate. Furthermore, the proposed model demonstrated two major reinforcing components: “the fiber effect” and “the loop effect.” The latter effect is the key benefit and the main advantage of using looped fibers over ordinary fibers in soil reinforcement. Altogether, there is a close agreement between finite element method outputs and experimental results, suggestive of a novel technical textile material that could potentially be used in geotechnical engineering.

Large Scale Direct Shear Tests on Reinforced Soil

1989 ◽  
Vol 29 (1) ◽  
pp. 18-30 ◽  
Author(s):  
Ennio M. Palmeira ◽  
George W.E. Milligan
Keyword(s):  
Large Scale ◽  
Reinforced Soil ◽  
Direct Shear ◽  
Shear Tests ◽  
Direct Shear Tests

Effect of Random Inclusion of Palm Fibers on Strength Characteristics of Shanghai Cohesive Soil

2015 ◽  
Vol 1096 ◽  
pp. 572-581
Author(s):  
Ji Li Qu ◽  
Dong Xue Zhao ◽  
Bei Bei Li
Keyword(s):  
Cohesive Soil ◽  
Reinforced Soil ◽  
Strength Characteristics ◽  
Test Results ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Shear Tests ◽  
Residual Shear Strength ◽  
Direct Shear Tests ◽  
Fiber Reinforced Soil

Abstract This paper presents the effect of random inclusion of palm fibers on strength characteristics of Shanghai cohesive soil. Locally available cohesive soil (CL) is used as medium and palm fibers with three lengths (l = 6, 12 and 18 mm) are used as reinforcement. Soil is compacted with standard Proctor’s maximum density with low percentage of reinforcement (0–1% by weight of oven-dried soil). Direct shear tests, unconfined compression tests and CBR tests were conducted on un-reinforced as well as reinforced soil to investigate the strength characteristics of fiber-reinforced soil. The test results reveal that the inclusion of randomly distributed palm fibers in soil increases peak and residual shear strength, unconfined compressive strength and CBR value of soil. It is noticed that the optimum fiber content for achieving maximum strength is 0.6–0.8% of the weight of oven-dried soil for fiber length 12 mm.

scholarly journals Sand- and Clay-Photocured-Geomembrane Interface Shear Characteristics Using Direct Shear Test

2021 ◽  
Vol 13 (15) ◽  
pp. 8201
Author(s):  
Lihua Li ◽  
Han Yan ◽  
Henglin Xiao ◽  
Wentao Li ◽  
Zhangshuai Geng
Keyword(s):  
Soil Surface ◽  
Friction Angle ◽  
Direct Shear ◽  
Tensile Crack ◽  
Shear Tests ◽  
Interface Shear ◽  
Direct Shear Tests ◽  
Carbon Black Powder ◽  
Shear Characteristics ◽  
Impermeable Layer

It is well known that geomembranes frequently and easily fail at the seams, which has been a ubiquitous problem in various applications. To avoid the failure of geomembrane at the seams, photocuring was carried out with 1~5% photoinitiator and 2% carbon black powder. This geomembrane can be sprayed and cured on the soil surface. The obtained geomembrane was then used as a barrier, separator, or reinforcement. In this study, the direct shear tests were carried out with the aim to investigate the interfacial characteristics of photocured geomembrane–clay/sand. The results show that a 2% photoinitiator has a significant effect on the impermeable layer for the photocured geomembrane–clay interface. As for the photocured geomembrane–sand interface, it is reasonable to choose a geomembrane made from a 4% photoinitiator at the boundary of the drainage layer and the impermeable layer in the landfill. In the cover system, it is reasonable to choose a 5% photoinitiator geomembrane. Moreover, as for the interface between the photocurable geomembrane and clay/sand, the friction coefficient increases initially and decreases afterward with the increase of normal stress. Furthermore, the friction angle of the interface between photocurable geomembrane and sand is larger than that of the photocurable geomembrane–clay interface. In other words, the interface between photocurable geomembrane and sand has better shear and tensile crack resistance.

scholarly journals Experimental and Numerical Investigation on the Steel Reinforced Grout (SRG) Composite-to-Concrete Bond

2020 ◽  
Vol 4 (4) ◽  
pp. 182
Author(s):  
Luciano Ombres ◽  
Salvatore Verre
Keyword(s):  
Bond Length ◽  
Failure Modes ◽  
Peak Load ◽  
Element Model ◽  
Test Results ◽  
Shear Tests ◽  
Bond Slip ◽  
Bond Behavior ◽  
Direct Shear Tests ◽  
Inorganic Matrix

In the paper, the bond between a composite strengthening system consisting of steel textiles embedded into an inorganic matrix (steel reinforced grout, SRG) and the concrete substrate, is investigated. An experimental investigation was carried out on medium density SRG specimens; direct shear tests were conducted on 20 specimens to analyze the effect of the bond length, and the age of the composite strip on the SRG-to-concrete bond behavior. In particular, the tests were conducted considering five bond length (100, 200, 250, 330, and 450 mm), and the composite strip’s age 14th, 21st, and 28th day after the bonding. Test results in the form of peak load, failure modes and, bond-slip diagrams were presented and discussed. A finite element model developed through commercial software to replicate the behavior of SRG strips, is also proposed. The effectiveness of the proposed numerical model was validated by the comparison between its predictions and experimental results.

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