Download or read book Testing and Acceptance Criteria for Geosynthetic Clay Liners written by Larry W. Well and published by ASTM International. This book was released on 1997 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: An engineering perspective on the liners, which are used as barriers for containing liquid and in conjunction with geomembranes in landfills and capping systems. Explore aspects of testing for shear strength and long-term creep, issues and methods of testing for hydraulic conductivity, and specifica
Download or read book Laboratory Hydraulic Conductivity Testing of GCLs in Flexible Wall Permeameters written by JJ. Bowders and published by . This book was released on 1997 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the important properties of geosynthetic clay liners (GCLs) is hydraulic conductivity. In the laboratory, hydraulic conductivity of GCLs is typically measured in flexible-wall permeameters. The most important variables in hydraulic conductivity testing of GCLs are addressed, including (i) trimming the GCL specimen; (ii) determining the thickness of the specimen; (iii) selecting the effective stress; (iv) selecting the hydraulic gradient; and (v) selecting the first wetting liquid and permeant liquid. A round-robin testing program was conducted in which 18 laboratories independently measured the hydraulic conductivity of a GCL that was permeated with water. The test specimens all came from the same GCL sample. The coefficient of variation, accounting for all sources of variability, was 42%. For experienced laboratories, this value reduced to 35%, which was identical to the variation in quality control tests performed over a 7-month period by the manufacturer on a variety of GCL samples. The round-robin test results are encouraging; there was less variability than might be expected, considering the difficulty in accurately measuring the hydraulic conductivity of relatively impermeable materials such as GCLs.
Download or read book Comparing GCL Performance Using Rigid Versus Flexible Wall Permeameters written by GR. Koerner and published by . This book was released on 2004 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geosynthetic clay liners consist of a layer of bentonite supported by various types of geosynthetics to form a composite material. Their primary function is to serve as liners for environmental, geotechnical and transportation applications. These materials are conformance tested as well as designed based upon their hydraulic conductivity. There are currently two different permeability tests used to measure the permeability of these materials. They are rigid and flexible wall variations of ASTM D5887 entitled Test Method for Measurement of Index Flux through Saturated Geosynthetic Clay Liner Specimens Using Flexible Wall Permeameter. It is the intent of this paper to illustrate how results are influenced by different equipment. This issue is relevant because it appears that many European and Asian testing laboratories are tending toward rigid walled testing, whereas laboratories in the USA are testing via flexible permeameters.
Download or read book Comparison of Laboratory Measured GCL Hydraulic Conductivity Based on Three Permeameter Types written by RJ. Petrov and published by . This book was released on 1997 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specimen preparation, installation, and testing procedures are presented for testing a needle-punched geosynthetic clay liner (GCL) in a consolidation-type, fixed-ring constant-flow-rate hydraulic conductivity apparatus. The proposed approach is illustrated by reporting the results obtained for a GCL statically confined to effective stresses of ~3 and ~35 kPa, hydrated and permeated with distilled water and concentrated aqueous salt solutions (0.6 and 2.0 N NaCl), and sequentially permeated with concentrated aqueous salt solutions (0.6 and 2.0 N NaCl) after initial permeation with distilled water. The issue of potential preferential sidewall flow in the fixed-ring permeameter tests was then addressed by comparing results with those conducted under otherwise similar testing conditions in a double-ring and flexible-wall permeameter. Reasonable reproducibility of the test results was obtained between the different types of permeameters, suggesting that, if present, preferential sidewall flow was negligibly small and was not significant on the calculated hydraulic conductivity values. This conclusion was found to be valid for the range of permeant types (distilled water and 0.6 and 2.0 N NaCl), static-confining stresses, and hydrating mediums considered. Premature arrival of the salt solution front in the effluent (i.e., solute breakthrough) during fixed-ring hydraulic conductivity testing was explained as a probable diffusion-dominated transport mechanism through the relatively thin GCL specimens.
Download or read book Fixed Wall Versus Flexible Wall Permeameters written by DC. Anderson and published by . This book was released on 1985 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Permeameters are of two general types: fixed-wall and flexible-wall cells. A controversy has developed over which type of cell is best suited for measuring the hydraulic conductivity of relatively impermeable, fine-grained soils. The various types of permeameters are discussed and their relative advantages and disadvantages are listed. Differences in applied stress, boundary leakages, and degree of saturation are the major differences between cells. It is concluded that no one type of cell is best suited to all applications. Data show that the type of permeameter used has little effect for laboratory-compacted clay permeated with water but can have a major effect for clays permeated with concentrated organic chemicals. Fixed-wall cells are perhaps best suited to testing laboratory-compacted clays that will be subjected to little or no effective overburden pressure in the field. Flexible-wall cells are better suited to testing undisturbed samples of soil (to minimize boundary leakages) and testing soils that will be subjected to significant effective stress.
Download or read book Variability of Saturated Hydraulic Conductivity Measurements Made Using a Flexible Wall Permeameter written by C. H. Benson and published by . This book was released on 2016 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was conducted following the procedures in ASTM E691-14 (Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method) to develop a precision statement for hydraulic conductivity measurement of fine-grained soils using Method C (falling head, rising tailwater elevation) of ASTM D5084-10 (Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter). Twelve laboratories conducted tests on three replicate specimens of three fine-grained soils (9 specimens total per laboratory) from the ASTM Reference Soils Program: Soil ML (silt), Soil CL (low plasticity clay), and Soil CH (high plasticity clay). The data indicated that the measurement variability for hydraulic conductivity is modest but not negligible, and probably contributes to the spatial variability reported in past studies of hydraulic conductivity. No systematic relationships were observed between variability in hydraulic conductivity and testing time (consolidation, permeation), backpressure, B-coefficient achieved at end of consolidation, compliance with the termination criteria, or specimen compaction conditions. Many laboratories did not comply with the test standard or the supplemental instructions, which may indicate that greater oversight of geotechnical laboratories is needed via accreditation and auditing programs. Analysis of the data indicate that hydraulic conductivity can be measured using Method C of ASTM D5084 within a factor of 2 for the 10-6 cm/s range, a factor of 1.5 for the 10-8 cm/s range, and a factor of 4 for the 10-9 cm/s range.
Download or read book Measurement of Hydraulic Properties of Geosynthetic Clay Liners Using a Flow Box written by DE. Daniel and published by . This book was released on 1997 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important property of geosynthetic clay liners (GCLs) is hydraulic conductivity. The authors describe and evaluate a new device, a GCL flowbox, that offers several advantages over large tanks or flexible-wall permeameters. The GCL flowbox can be used to test large-scale intact specimens, overlapped specimens with a full-width seam, and specimens subjected to environmental stresses such as freeze-thaw. A transparent, acrylic GCL flowbox was developed for testing at low normal stresses, and a metal version was developed for applying higher normal stresses. Results from the GCL flowbox compared favorably to results obtained with tanks and flexible-wall permeameters. It is concluded that the GCL flowbox provides a convenient and reliable testing methodology for verifying the hydraulic conductivity of both intact specimens and overlapped GCL panels.
Download or read book Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter written by and published by . This book was released on 2004 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison Between Various Field and Laboratory Measurements of the Hydraulic Conductivity of Three Clay Liners written by G. Didier and published by . This book was released on 2002 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: For waste facilities, field assessment of the hydraulic conductivity of fine- grained soils has been a real challenge for the past decades that has led to several types of test methods. Although standards (ASTM, NF, etc.) have been adopted in many countries, any test method needs careful application for constructing quality-control programs. The type of apparatus, its geometry, and even specimen preparation may be major sources of discrepancy. We compared hydraulic-conductivity values obtained from various field-testing methods (open, sealed, single and double infiltrometers, and borehole methods), and laboratory-testing methods such as oedometer cells or rigid and flexible-wall permeameters. Three materials were tested in this study: a compacted sandbentonite mixture, compacted clayey silt, and natural sandy clay. The field tests were run on soil-test pads whose characteristics were defined beforehand in the laboratory and the field. Comparison of the results shows a large range of hydraulic-conductivity values for a single soil sample. Such variability can commonly be explained by a scale effect, as demonstrated by the use of various types of diameter or geometry for the field or laboratory tests. Soil behavior (swelling or shrinkage) and test-analysis methods (saturated or unsaturated-flow analysis) are other important parameters. In conclusion, we identified the main problems affecting tests with infiltrometers and permeameters, and how they can be reduced or avoided by the improvement of current techniques.
Download or read book Geotechnical Engineering Handbook written by Braja M. Das and published by J. Ross Publishing. This book was released on 2011 with total page 801 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Geotechnical Engineering Handbook brings together essential information related to the evaluation of engineering properties of soils, design of foundations such as spread footings, mat foundations, piles, and drilled shafts, and fundamental principles of analyzing the stability of slopes and embankments, retaining walls, and other earth-retaining structures. The Handbook also covers soil dynamics and foundation vibration to analyze the behavior of foundations subjected to cyclic vertical, sliding and rocking excitations and topics addressed in some detail include: environmental geotechnology and foundations for railroad beds.
Download or read book Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter written by ASTM Committee D-18 on Soil and Rock and published by . This book was released on 2010 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flexible Wall Permeameter to Measure the Hydraulic Conductivity of Soils in Horizontal Direction written by G. Sridhar and published by . This book was released on 2013 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flexible wall permeability apparatus was modified for the direct measurement of the hydraulic conductivity of soils in the horizontal direction. Constant head permeability tests were carried out using the radial flow flexible wall permeameter on soil samples with central sand drain to allow the water to flow radially from the central sand drain towards a peripheral drain. Tests were also conducted using the conventional flexible wall permeameter on samples that were trimmed horizontally, so as to measure the hydraulic conductivity in the horizontal directions for comparison. The test results obtained from the proposed setup agrees well with those obtained from the samples that were trimmed horizontally, proving the validity of the results obtained from the proposed apparatus.
Download or read book Geotechnical and Geoenvironmental Engineering Handbook written by R. Kerry Rowe and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 1130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Preface. Dedication. List of Figures. List of Tables. List of Contributors. Basic Behavior and Site Characterization. 1. Introduction; R.K. Rowe. 2. Basic Soil Mechanics; P.V. Lade. 3. Engineering Properties of Soils and Typical Correlations; P.V. Lade. 4. Site Characterization; D.E. Becker. 5. Unsaturated Soil Mechanics and Property Assessment; D.G. Fredlund, et al. 6. Basic Rocks Mechanics and Testing; K.Y. Lo, A.M. Hefny. 7. Geosynthetics: Characteristics and Testing; R.M. Koerner, Y.G. Hsuan. 8. Seepage, Drainage and Dewatering; R.W. Loughney. Foundations and Pavements. 9. Shallo.
Download or read book Laboratory Investigations written by Louie Weston and published by Createspace Independent Publishing Platform. This book was released on 2017-01-30 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paper sludges are being used with increasing frequency for construction of hydraulic barrier layers in landfill final covers because they often have substantial clay content and relatively low hydraulic conductivity. This paper addresses the assessment of the hydraulic conductivity of paper sludges using data obtained from a series of laboratory and field tests conducted on two barrier layers constructed with paper sludge that were part of final cover test sections. Field hydraulic conductivities were measured using sealed double-ring infiltrometers (SDRIs) and two-stage borehole permeameters (TSBs). Laboratory tests were conducted in flexible-wall permeameters on undisturbed specimens collected as blocks and in thin-wall sampling tubes as well as remolded specimens. The in-service hydraulic conductivity, computed from water balance data, was also available for comparison. Analysis of the data shows that similar hydraulic conductivities are measured in large field tests and on small laboratory specimens regardless of whether the specimens are undisturbed or remolded. Based on the analysis, recommendations are made regarding the need for field testing, laboratory and field test methods, and sampling techniques.
Download or read book Advances in Geosynthetic Clay Liner Technology written by Robert E. Mackey and published by ASTM International. This book was released on 2004 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soon after the inception of ASTM D35.04 Subcommittee on Geosynthetic Clay Liners, the first symposium on Testing and Acceptance Criteria for Geosynthetic Clay Liners (GCLs), STP 1308, was held on 29 January 1996, in Atlanta, Georgia. The intention of the symposium was to bring together the current knowledge and understanding regarding this relatively new product used in containment systems. Since that symposium, numerous GCL standards have been developed along with a greater appreciation of the product's capabilities and limitations. ASTM D35 determined it was time to assess the current state of GCL technology to better address possible revisions of the present ASTM GCL standards and determine what new standards will be required in the future.
Download or read book A Comparison of Sample Preparation Methodology in the Evaluation of Geosynthetic Clay Liner GCL Hydraulic Conductivity written by S. Lucas and published by . This book was released on 1997 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The method of preparing a single needle-punched GCL product for evaluation of hydraulic conductivity in a flexible wall permeameter was examined. The test protocol utilized for this evaluation was GRI Test Method GCL-2 Permeability of GCLs. The GCL product consisted of bentonite clay material supported by a woven and a non-woven geotextile on either side. The method preparation focused on the procedure for separating the test specimen from the larger sample and whether these methods produced difficulty in generating reliable test data. The methods examined included cutting with a razor knife, scissors, and a circular die with the perimeter of the test area under wet and dry conditions. In order to generate as much data as possible, tests were kept brief. Flow was monitored only long enough to determine whether or not preferential flow paths appeared to be present. The results appear to indicate that any of the methods involved will work. Difficulties arose not from the development of preferential flow paths around the edges of the specimens, but from the loss of bentonite from the edges during handling.
Download or read book Cation Exchange and Long term Hydraulic Conductivity of Geosynthetic Clay Liners GCLs Permeated with Inorganic Salt Solutions written by Ho Young Jo and published by . This book was released on 2003 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
