Evaluation of Interface Shear Strength Properties of Geogrid-Reinforced Construction and Demolition Materials Using a Modified Large-Scale Direct Shear Testing Apparatus

2014 ◽  
Vol 26 (5) ◽  
pp. 974-982 ◽  
Author(s):  
A. Arulrajah ◽  
M. A. Rahman ◽  
J. Piratheepan ◽  
M. W. Bo ◽  
M. A. Imteaz
2020 ◽  
Vol 48 (5) ◽  
pp. 625-633 ◽  
Author(s):  
Farshid Maghool ◽  
Arul Arulrajah ◽  
Mehdi Mirzababaei ◽  
Cherdsak Suksiripattanapong ◽  
Suksun Horpibulsuk

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Arul Arulrajah ◽  
Suksun Horpibulsuk ◽  
Farshid Maghoolpilehrood ◽  
Wisanukorn Samingthong ◽  
Yan-Jun Du ◽  
...  

The interface shear strength properties of geogrid reinforced recycled foamed glass (FG) were determined using a large-scale direct shear test (DST) apparatus. Triaxial geogrid was used as a geogrid reinforcement. The geogrid increases the confinement of FG particles during shear; consequently the geogrid reinforced FG exhibits smaller vertical displacement and dilatancy ratio than FG at the same normal stress. The failure envelope of geogrid reinforced FG, at peak and critical states, coincides and yields a unique linear line possibly attributed to the crushing of FG particles and the rearrangement of crushed FG after peak shear state. The interface shear strength coefficientαis approximately constant at 0.9. This value can be used as the interface parameter for designing a reinforced embankment and mechanically stabilized earth (MSE) wall when FG is used as a lightweight backfill and triaxial geogrid is used as an extensible earth reinforcement. This research will enable FG, recently assessed as suitable for lightweight backfills, to be used together with geogrids in a sustainable manner as a lightweight MSE wall. The geogrid carries tensile forces, while FG reduces bearing stresses imposed on the in situ soil. The use of geogrid reinforced FG is thus significant from engineering, economical, and environmental perspectives.


Author(s):  
Jakub Stacho ◽  
Monika Sulovska ◽  
Ivan Slavik

The paper deals with the laboratory testing of coarse-grained soils that are reinforced using a geogrid. The shear strength properties were determined using a large-scale direct shear test apparatus. The tests were executed on original as well as on reinforced soil, when the geogrid was placed on a sliding surface, which permitted determining the shear strength properties of the soil-geogrid interface. The aim of the tests was to determine the interface shear strength coefficient α, which represents the ratio of the shear strength of the soil-geogrid interface to the unreinforced soil. The tests were executed on 3 samples of coarse-grained materials, i.e., poorly graded sand, poorly graded fine gravel and poorly graded medium gravel. Two types of geogrids were tested, i.e., a woven polyester geogrid and a stiff polypropylene geogrid. The results of the laboratory tests on the medium gravel showed that the reduction coefficient α reached higher values in the case of the stiff polypropylene geogrid. In the cases of the fine gravel and sand, the values of the interface coefficient α were similar to each other. The shear strength of the interface was reduced or was similar to the shear strength of unreinforced soil in a peak shear stress state, but significantly increased with horizontal deformations, especially for the fine gravel and sand. The largest value of the coefficient α was measured in the critical shear stress state. Based on the results of the testing, a correlation which allows for determining the optimal grain size distribution was obtained.


2010 ◽  
Vol 30 (8-9) ◽  
pp. 1544-1555 ◽  
Author(s):  
Dimitrios Zekkos ◽  
George A. Athanasopoulos ◽  
Jonathan D. Bray ◽  
Athena Grizi ◽  
Andreas Theodoratos

Author(s):  
Minh-Duc Nguyen ◽  
Minh-Phu Ho

The paper presents a series of modified direct shear tests to investigate the interface shear strength between clay and nonwoven geotextile under different normal stresses and degrees of saturation. The modified direct shear apparatus consists of a 60 mm × 60 mm square shear box assembly with a 60 mm × 60 mm acrylic block inserted in the bottom shear box. A woven geotextile layer was glued to the top of the acrylic block, while the top shear box was filled by the compacted clayey soil. The results revealed that the interface shear strength of clay and nonwoven geotextile reduced by 13.4-27.7% when changing from optimum moisture content (OMC) of the soil to saturation condition. The high permeability of nonwoven geotextile induced the dissipation of excess pore water pressure at the interface when shearing. As a result, the adhesion factor of the clay-geotextile interface increased from about 0.6 for the specimens at OMC to over 0.8 for consolidated saturated specimens. In contrast, for the impermeable reinforcement, the interface shear strength analysis of previous studies shows that the adhesion factor of the reinforcement and clayey soil would be reduced when increasing the water content of the clay specimens. Keywords: adhesion factor; clay; nonwoven geotextile, interface shear strength; saturation.


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