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Showing 1 to 20 of 23 for “"Geomembrane"”.
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An Investigation into the Effects of Asperities on Geomembrane/Geotextile Interface Shear Characteristics
Geomembranes are often utilized as fluid barriers in geotechnical applications such as landfills. Due to their relative impermeability and chemical resistance characteristics, they are usually used alongside other geosynthetics like geotextiles in landfills to constitute base, side-slope, and cover …
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Comparison of shear strength properties of textured polyethylene geomembrane interfaces in landfill liner systems
The interface shear strength between geomembranes and geosynthetics is a critical factor governing the stability of slopes that incorporate geosynthetics. In order to better characterise the shear properties of geomembranes, a wide-range of shear strength friction measurements were conducted. This …
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Two-Dimensional Analysis of Water-Filled Geomembrane Tubes Used as Temporary Flood-Fighting Devices
A water-filled geomembrane tube is considered for the purpose of temporary flood protection. With proper design, this tube can be a cheap and efficient breakwater, temporary levee, or cofferdam. This thesis considers a single tube resting on clay and sand foundations. A finite difference program, …
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Two-Dimensional Analysis of Four Types of Water-Filled Geomembrane Tubes as Temporary Flood-Fighting Devices
Two-dimensional analysis of four types of water-filled tube dams is carried out: an apron-tube dam, a single baffle tube dam, a sleeved tube dam, and a stacked tube dam. Since the analysis of the water-filled tube dam involves highly nonlinear geometric deformations and interactions with soil, …
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Physical Performance of Geomembranes Used in Heap Leach Pad Applications
Geomembranes (GMB) are normally used as part of the liner system in heap leach pads. There is a need to quantify tensile strains in the geomembrane that could affect short-term puncture and long-term performance of the GMB. In this thesis, short-term tensile strains arising from indentations caused …
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Field-Scale Monitoring and Laboratory Simulation of Geosynthetic Liners During Construction and After Placement of Waste
Two physical issues of geomembrane wrinkle deformations and downslope shear deformations – that need to be considered to obtain good long-term geomembrane liner performance – are examined. First, field-scale monitoring of geomembrane wrinkles in a 1.5-mm-thick, black high-density polyethylene …
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Field Performance of Exposed Geosynthetic Composite Liner Systems
Geosynthetic clay liners (GCL) overlain by a geomembrane (GMB) in a geosynthetic composite liner system in landfill liner and other waste containment applications can be left exposed for weeks, months, or in some extreme cases, even years. Three known consequences of leaving a GMB-GCL composite …
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Calculating and Limiting Local Strains in Geomembranes From Gravel Indentations
… in municipal solid waste landfill base geomembrane liners are investigated with an emphasis on quantifying how strains are obtained and providing methods for limiting long-term local geomembrane strains below allowable levels. This involved the development of new experimental techniques …
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Long-Term Performance of HDPE Geomembranes as Landfill Liners
High density polyethylene (HDPE) geomembranes are normally used as part of a composite liner for waste containment facilities such as municipal solid waste (MSW) landfills and heap leach pads. Field conditions, which include physical stresses on the geomembrane, elevated operating temperatures, and …
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Laboratory Investigation of the Effects of Temperature and Moisture on Interface Shear Strength of Textured Geomembrane and Geosynthetic Clay Liner
… and moisture on the shear strength of textured geomembrane (T-GM) and geosynthetic clay liner (GCL) interface. Several landfill slope failures involving geosynthetics have occurred within the past three decades. Interface shear strength of T-GM/GCL is well documented for testing conducted at …
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Elevated temperatures in waste containment facilities
… temperatures to high density polyethylene (HDPE) geomembrane service life. MSW landfills with a gas collection and control system used to comply with federal regulations (40 CFR, Part 60, Subpart WWW) operate each gas extraction well with a landfill gas temperature less than 55°C (131°F) because …
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Effects of Freezing Temperature on Interface Shear Strength of Landfill Geosynthetic Liner
… strength of geocomposite clay liner (GCL) and geomembrane interface in landfills. Using direct shear tests, shear stress was measured as a function of normal load to determine the values of interface frictional angle and adhesion of the geosynthetic interface. The variation of interface …
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Containment of Organic Contaminants Using Geosynthetics
… and xylenes (BTEX) and PCBs through geomembranes are evaluated. Diffusion of BTEX is also evaluated through vapour barriers, as well as diffusion of PCBs through a compacted clay liner (CCL) and a GCL. The permeation coefficient (Pg) for BTEX diffusion was lowest for high density …
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Ageing of HDPE Geomembranes Used to Contain Landfill Leachate or Hydrocarbon Spills
The ageing of high density polyethylene geomembrane (GM) liners used to minimize advection and diffusion of contaminants in municipal solid waste landfill leachate and in hydrocarbon spills to the environment is examined. The evaluation of the ageing of GMs used in landfills involved four …
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An Investigation of the Effects of Specimen Gripping Systems on Shear Stress at the Geosynthetic/Geosynthetic Interface in Landfill Applications
… installed in a landfill i.e. geotextile, geomembrane and geosynthetic clay liner. The results revealed that there exists a dissimilarity in the mobilized shear strength at geosynthetic interface when the NP is used as compared to the utilization of the SP due to the specimen engagement …
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Coal Combustion Waste Disposal Facility Design: Electric Power Cooperative Selby, South Dakota
… of a 60 mil high density polyethylene (HDPE) geomembrane overlying a compacted soil layer were evaluated with and without a leachate collection system. Two cover systems were evaluated to predict the performance of the closed landfill. Again, the HELP model was used to determine the predicted …
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Comparative Assessment of Single & Double Interface Shear Strength Properties: A Case Study of a Landfill Project in the Western Cape Province, South Africa
… three nonwoven geotextiles, two smooth-sided geomembranes, a synthetic cuspate drain, sand, gravelly sand (GS), and leachate collection stone (LCS). All tests were conducted at applied normal pressures of 150, 300, & 450 kPa under saturated conditions with fresh tap water at a 1mm/min shearing …
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Dimensional Stability of Geosynthetic Clay Liners in Landfill Applications
… on a compacted sand subgrade beneath an exposed geomembrane liner outdoors in late summer.</p> <p>Initial moisture content tests resulted in shrinkage strains as high as 20% after 20 wet-dry cycles. GCLs ranged from slightly anisotropic [approximately 1.1:1 ratio of machine (MD) to cross-machine …
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A Comparative Study on Shear Strength Testing of Single and Multi-layer Interfaces using Large Direct Shear Apparatus
… three geosynthetics were used: geotextile (GTX), geomembrane (GMB) and geosynthetic clay liner (GCL), which generally constitute the critical interface components of a lining system in a modern South African landfill liner. Two soils were utilised as a part of the materials required for the …
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HYDRAULIC PERFORMANCE OF GEOSYNTHETIC LINERS IN TAILINGS STORAGE FACILITIES
Experiments are conducted to investigate the impact of fines content on the compressibility and permeability of the cyclone tailings, and to quantify leakage through a GMB hole overlain by saturated tailings. The effect of hole shapes, hole sizes, GMB thicknesses, tailings thicknesses, tailings …
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