Pullout Testing of Geogrids in Tire Shreds and Rubber-Sand

2009 ◽  
pp. 109-109-13 ◽  
Author(s):  
A Bernal ◽  
RH Swan ◽  
R Salgado ◽  
CW Lovell
Keyword(s):  
Tire Shreds ◽  
Pullout Testing

scholarly journals Experimental Pullout Capacity of Screw Piles in Dry Gypseous Soil

2021 ◽  
Vol 318 ◽  
pp. 01002
Author(s):  
Mahdi O. Karkush ◽  
Omar J. Mukhlef
Keyword(s):  
Relative Density ◽  
Offshore Structures ◽  
Pullout Capacity ◽  
Single Screw ◽  
Gypsum Content ◽  
Pullout Testing ◽  
D 20 ◽  
Pile Model ◽  
Supporting Structures ◽  
Gypseous Soil

Screw piles are widely used in supporting structures subjected to pullout forces, such as power towers and offshore structures, and this research investigates their performance in gypseous soil of medium relative density. The bearing capacity and displacement of a single screw pile model inserted in gypseous soil with various diameters (D = 20, 30, and 40) mm are examined in this study. The soil used in the testing had a gypsum content of 40% and the bedding soil had a relative density of 40%. To simulate the pullout testing in the lab, a physical model was manufactured with specific dimensions. Three steel screw piles with helix diameters of 20, 30, and 40 mm are used, with a total length of 500 mm. The helix is continuous over the pile's embedded depth of 400 mm. The results of tests revealed that decreasing the length to diameter (H/D) ratio resulted in a higher pullout capacity of screw piles and a lower corresponding displacement.

Large-scale pullout testing and numerical evaluation of U-shape polymeric straps

2019 ◽  
Vol 26 (3) ◽  
pp. 237-250 ◽  
Author(s):  
S. Razzazan ◽  
A. Keshavarz ◽  
M. Mosallanezhad
Keyword(s):  
Numerical Evaluation ◽  
Large Scale ◽  
Pullout Testing

Load-strain-displacement response of geosynthetics in monotonic and cyclic pullout

1998 ◽  
Vol 35 (2) ◽  
pp. 183-193 ◽  
Author(s):  
D M Raju ◽  
R J Fannin
Keyword(s):  
Relative Displacement ◽  
Cyclic Loads ◽  
Normal Stresses ◽  
Constant Ratio ◽  
Pullout Resistance ◽  
Maximum Resistance ◽  
Constant Rate ◽  
Pullout Testing ◽  
Pullout Behaviour ◽  
Cyclic Dynamic

Mobilization of the pullout resistance of geosynthetics in monotonic and cyclic modes is described from both displacement- and load-controlled tests performed at normal stresses in the range 4-17 kPa. The tests were performed on three geogrids and two geomembranes embedded nearly 1.0 m in a uniformly graded sand. Results for load-controlled tests at a constant rate of 0.25 kN/(m ·min-1), followed by several series of load cycles of increasing amplitude, are compared with displacement-controlled tests at a constant rate of 0.5 mm/min. In general the geogrids behave as an equivalent textured sheet. Pullout behaviour, and especially the incremental displacement mobilized at cyclic loads close to the maximum resistance, is found to vary with type of geogrid. In only one case was cyclic pullout resistance of a grid found to exceed the monotonic resistance. A comparison of the cyclic and monotonic response yields a constant ratio of pullout resistance at large displacement, but one which is not unique to a particular specimen. Cyclic strains of decreasing amplitude are mobilized along a test specimen, with most of the necessary relative displacement occurring close to the loaded end and the embedded end showing little response.Key words: pullout testing, monotonic, cyclic, dynamic, geosynthetics, reinforced walls.

Modelling the clogging of coarse gravel and tire shreds in column tests

2007 ◽  
Vol 44 (11) ◽  
pp. 1273-1285 ◽  
Author(s):  
R. Kerry Rowe ◽  
Dan Babcock
Keyword(s):  
Laboratory Tests ◽  
Suspended Solids ◽  
Good Prediction ◽  
Column Tests ◽  
Average Grain Size ◽  
Tire Shreds ◽  
Different Types ◽  
Monod Kinetic ◽  
Coarse Gravel ◽  
Waste Leachate

A combination of data from laboratory tests and modelling is reported for both coarse gravel (19–38 mm) and two types of tire shred permeated with municipal solid waste leachate. It is suggested that the dispersivity of both the coarse gravel (initially about 4 mm) and tire shreds (initially about 45 mm) increases as the porosity of the drainage media is reduced because of clogging. The detachment of biofilm caused by growth and shear is examined and both are found to influence clogging. The average grain size estimated based on the measured surface area of the particles within a unit volume is shown to provide a good prediction of the rate of clogging for gravel and a conservative prediction for tire shreds. The size and density of suspended solids in leachate is found to significantly influence clogging rates. It is shown that Monod kinetic constants deduced for gravel at 27 °C give a good prediction of clogging for two different types of tire shred at the same temperature. Calibrated parameters used with the BioClog model are shown to give good fits to the porosity of both gravel and tire shred drainage material in laboratory column tests over time periods of up to 2 years.

Change in leachate chemistry and porosity as leachate permeates through tire shreds and gravel

2005 ◽  
Vol 42 (4) ◽  
pp. 1173-1188 ◽  
Author(s):  
Reagan McIsaac ◽  
R Kerry Rowe
Keyword(s):  
Hydraulic Conductivity ◽  
Attractive Potential ◽  
Spatial And Temporal Variation ◽  
Equivalent Thickness ◽  
Leachate Collection ◽  
Rubber Tire ◽  
Tire Shreds ◽  
Potential Alternative ◽  
Long Term Performance ◽  
Term Performance

Rubber tire shreds are an attractive potential alternative to conventional gravel in the drainage layer of leachate collection systems at the base of landfills, yet the clogging and thus the long-term performance of tire shreds in this application is not known. This paper presents the results of an experimental investigation into the clogging potential of rubber tire shreds used as part of a leachate collection system at the base of a landfill when permeated with leachate. Experimental columns filled with two different rubber tire shreds and a conventional gravel drainage material were used to study the spatial and temporal variation of leachate characteristics and porosity changes within the drainage materials. It is shown that there are significant differences in the pore structures of the drainage materials and that these differences affect clog development and the length of time it takes for the hydraulic conductivity to drop below a threshold of 10–5 m/s. The gravel is found to have a service life at least three times greater than that of an equivalent thickness of compressed (at 150 kPa) tire shred.Key words: tire shreds, landfill, clogging, hydraulic conductivity, porosity, leachate collection.

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