Appraisal of Anchor Arrangement and Size On Sand-Geogrid Interaction In Direct Shear

Mapping Intimacies ◽

10.21203/rs.3.rs-1104294/v1 ◽

2021 ◽

Author(s):

Mahmood Reza Abdi ◽

Mehdi PourRamezan Chafjiri

Keyword(s):

Normal Pressure ◽

Soil Reinforcement ◽

Shear Load ◽

Direct Shear ◽

Shear Surface ◽

Analysis And Design ◽

Reinforced Earth ◽

Earth Structures ◽

Shear Box ◽

Reinforcement Interaction

Abstract Soil – reinforcement interaction is a major factor in the analysis and design of reinforced earth structures. In current research the effects of attaching elements of different size and numbers as anchors on enhancement of interaction at soil - geogrid interface under direct shear conditions were studied. Poorly and well graded sands (SC & Sf), a high density polyethylene geogrid, anchors with three different size and numbers (layouts) and clamping length of 2cm from shear surface were used. Samples were prepared dry at a relative density of 80% in a 30×30cm direct shear box and subjected to normal pressures of 12.5, 25 and 50kPa with the shear load applied at a rate of 1mm/min. Results of the assessment show that anchored geogrids improve shear resistance at interface mainly due to mobilization of passive soil resistance that is significantly influenced by the magnitude of the normal pressure and the number and size of anchors. Interaction enhancements achieved varied between a minimum of 8% and a maximum of 42%.

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Shear-friction behavior of concrete-to-concrete interface under direct shear load

Engineering Structures ◽

10.1016/j.engstruct.2021.112211 ◽

2021 ◽

Vol 238 ◽

pp. 112211

Author(s):

Jin Xia ◽

Kuang-yi Shan ◽

Xiao-hui Wu ◽

Run-li Gan ◽

Wei-liang Jin

Keyword(s):

Shear Load ◽

Direct Shear ◽

Friction Behavior ◽

Shear Friction ◽

Concrete Interface

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Time-Dependent Response of a Recycled C&D Material-Geotextile Interface under Direct Shear Mode

Materials ◽

10.3390/ma14113070 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3070

Author(s):

Fernanda Bessa Ferreira ◽

Paulo M. Pereira ◽

Castorina Silva Vieira ◽

Maria de Lurdes Lopes

Keyword(s):

Shear Stress ◽

Stress Relaxation ◽

Shear Displacement ◽

Time Dependent ◽

Shear Behaviour ◽

Displacement Rate ◽

Shear Mode ◽

Direct Shear ◽

Constant Displacement ◽

Shear Box

Geosynthetic-reinforced soil structures have been used extensively in recent decades due to their significant advantages over more conventional earth retaining structures, including the cost-effectiveness, reduced construction time, and possibility of using locally-available lower quality soils and/or waste materials, such as recycled construction and demolition (C&D) wastes. The time-dependent shear behaviour at the interfaces between the geosynthetic and the backfill is an important factor affecting the overall long-term performance of such structures, and thereby should be properly understood. In this study, an innovative multistage direct shear test procedure is introduced to characterise the time-dependent response of the interface between a high-strength geotextile and a recycled C&D material. After a prescribed shear displacement is reached, the shear box is kept stationary for a specific period of time, after which the test proceeds again, at a constant displacement rate, until the peak and large-displacement shear strengths are mobilised. The shear stress-shear displacement curves from the proposed multistage tests exhibited a progressive decrease in shear stress with time (stress relaxation) during the period in which the shear box was restrained from any movement, which was more pronounced under lower normal stress values. Regardless of the prior interface shear displacement and duration of the stress relaxation stage, the peak and residual shear strength parameters of the C&D material-geotextile interface remained similar to those obtained from the conventional (benchmark) tests carried out under constant displacement rate.

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