Download or read book The field hydraulic conductivity of compacted clay test pads written by Owen Robert Michaelis and published by . This book was released on 1996 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Representative Sample Size for Hydraulic Conductivity of Compacted Clay written by Fransiscus S. Hardianto and published by . This book was released on 1992 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Relationship of Laboratory and Field determined Hydraulic Conductivity in Compacted Clay Layer written by A. S. Rogowski and published by . This book was released on 1990 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Variability in the Hydraulic Conductivity of a Test Pad Liner System Using Different Testing Techniques written by Matthew Jonathan Nanak and published by . This book was released on 2013 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Historic methods (the time lag approach, the velocity approach, and the Z-t approach), utilized to reduce two stage borehole test data, were evaluated. Two of the historic methods provided viable results and were used for this research project. Additionally, these two methods are recommended for reducing two stage borehole test data in the future. Flexible wall permeameter and soil index laboratory testing were conducted on the soil used to construct three environmentally controlled compacted clay liners (test pads) to develop a zone of acceptance (placement window). Using the results from the laboratory testing, two acceptance criterions were evaluated, while one criterion was used for construction purposes and is recommended. Two stage borehole testing was conducted in Test Pads 1 and 2, while sealed double ring infiltrometer testing was conducted in Test Pad 3. After in-situ hydraulic conductivity testing was completed for Test Pads 1 and 2, Shelby tube and hand carved samples were obtained and laboratory testing was performed on the samples. Time domain reflectometry probes and tensiometers were used to monitor the movement of the wetting front during testing conducted in Test Pad 3. Hydraulic conductivity results obtained from each testing method were compared. The laboratory obtained hydraulic conductivity values from testing conducted on Shelby tube samples were compared to laboratory hydraulic conductivity values obtained from testing conducted on hand carved samples. The laboratory hydraulic conductivity values obtained from testing conducted on Shelby tube and hand carved samples were compared to field hydraulic conductivity values obtained from two stage borehole hydraulic conductivity testing. The field hydraulic conductivity values obtained from two stage borehole hydraulic conductivity testing were compared to field hydraulic conductivity values obtained from sealed double ring infiltrometer hydraulic conductivity testing. Collection of soil specimens using Shelby tubes causes the soil to compress and thereby changes the soil parameters (unit weight and hydraulic conductivity). Results of this research project indicate that comparable hydraulic conductivities within half an order of magnitude can be obtained from two stage borehole and sealed double ring infiltrometer field testing and laboratory testing conducted on hand carved and Shelby tube flexible wall samples.
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 State of the art Field Hydraulic Conductivity Testing of Compacted Soils written by Joseph O. Sai and published by . This book was released on 1991 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydraulic Conductivity and Waste Contaminant Transport in Soil written by David Edwin Daniel and published by ASTM International. This book was released on 1994 with total page 617 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field Hydraulic Conductivity Tests for Compacted Soil Liners written by JO. Sai and published by . This book was released on 1990 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Field hydraulic conductivity tests are required to determine the in situ hydraulic conductivity of compacted clay soils used in the liners for hazardous waste management facilities. The test must be capable of measuring hydraulic conductivities of 1 × 10-9 m/s or less, and the values obtained must be representative of the overall soil liner. Few of the methods available are capable of both measuring low hydraulic conductivities and obtaining representative values. Test methods which meet these requirements include large single-ring infiltrometers, sealed double-ring infiltrometers, and collection lysimeters. The main drawback in the use of collection lysimeters is that it can take months to obtain steady-state hydraulic conductivity values. Sealed double-ring infiltrometers are practical to use and have the advantage of few ambiguities in the experimental procedures, few possibilities for yielding false low values, and are large enough to yield results representing the overall liner characteristics.
Download or read book An Evaluation of Borehole Hydraulic Conductivity Equations and Field Determined Soil Water Characteristic Curves written by Johnathan Dale Blanchard and published by . This book was released on 2017 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The methods utilized to determine the hydraulic conductivity of compacted clay liners (CCLs) are of importance for safe guarding the environment from landfill leachate. Therefore, the methods utilized in the analysis of the Two Stage Borehole (TSB) test, as described in the ASTM D6391-11 (Method A, B, and C) standard, were evaluated. Data from hydraulic conductivity tests, as performed on three test pads, were utilized to review the ASTM D6391-11 equations. Additionally, two test pads were instrumented with volumetric water content and soil water matric potential sensors to facilitate the determination of field-obtained soil water characteristic curves (SWCCs) and hydraulic conductivity functions (k-functions) for unsaturated soils. For the determination of the SWCCs and k-functions, each test pad was subjected to an infiltration cycle, using either a sealed double ring infiltrometer or a two-stage borehole infiltrometer, followed by a drying cycle. To compare the results that were obtained from the field-obtained SWCCs and k-functions, laboratory tests were performed on Shelby tube samples acquired from the corresponding test pad. The obtained data were fitted using the van Genuchten model and the RETC (RETention Curve) program. The results that were obtained from TSB testing led to the conclusion that Method B and C, as written in the ASTMs D6391-11 standard contained errors that impacted the results that were obtained from hydraulic conductivity testing. Specifically, utilizing Method C provided results that were four times greater than the hydraulic conductivity and utilizing Method B provided results that were as much as two orders of magnitude greater than the hydraulic conductivity. Several recommendations are proposed herein to ensure accurate hydraulic conductivity analysis is performed in the future. It was further determined that a poor agreement exists between field-obtained and laboratory-obtained k-functions and SWCCs, as reported in other studies. Therefore, field-obtained k-functions are preferential, when available.
Download or read book Effect of Freeze thaw on the Hydraulic Conductivity of Barrier Materials written by Jason Frederic Kraus and published by . This book was released on 1994 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of the Performance of Engineered Waste Containment Barriers written by National Research Council and published by National Academies Press. This book was released on 2007-08-22 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: President Carter's 1980 declaration of a state of emergency at Love Canal, New York, recognized that residents' health had been affected by nearby chemical waste sites. The Resource Conservation and Recovery Act, enacted in 1976, ushered in a new era of waste management disposal designed to protect the public from harm. It required that modern waste containment systems use "engineered" barriers designed to isolate hazardous and toxic wastes and prevent them from seeping into the environment. These containment systems are now employed at thousands of waste sites around the United States, and their effectiveness must be continually monitored. Assessment of the Performance of Engineered Waste Containment Barriers assesses the performance of waste containment barriers to date. Existing data suggest that waste containment systems with liners and covers, when constructed and maintained in accordance with current regulations, are performing well thus far. However, they have not been in existence long enough to assess long-term (postclosure) performance, which may extend for hundreds of years. The book makes recommendations on how to improve future assessments and increase confidence in predictions of barrier system performance which will be of interest to policy makers, environmental interest groups, industrial waste producers, and industrial waste management industry.
Download or read book Relationship of Laboratory and Field Determined Hydraulic Conductivity in Compacted Clay Layer written by and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field and Laboratory Measurements of the Hydraulic Conductivity of Compacted Mine Waste Rock written by Todd H. Hill and published by . This book was released on 1998 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydraulic Conductivity of Thirteen Compacted Clays written by John Mathew Trast and published by . This book was released on 1993 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field Permeability Test for Clay Liners written by DE. Daniel and published by . This book was released on 1985 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of measuring the hydraulic conductivity of compacted clay liners in the field using single-ring infiltrometers has been developed. It is assumed that the ring has a diameter that is no less than the thickness of the clay liner and that the clay liner is underlain by a freely draining material with negligible suction. Finite element analyses were performed to develop correction factors that account for horizontal seepage for cases in which the ring infiltrometer is partially embedded into the liner. The correction factors were developed for a range in diameter of the ring and for ratios of horizontal to vertical hydraulic conductivity of 1, 10, and 100. Laboratory experiments were conducted to verify the results of finite-element analyses, but the laboratory results showed considerable scatter and were successful only in demonstrating that the finite-element results show the proper trends. Finally, the test method was tried in the field on a full-sized clay liner in which the actual hydraulic conductivity of the entire liner could be calculated from the known rate of leakage. The hydraulic conductivity measured in the infiltration test agreed almost perfectly with the computed overall hydraulic conductivity of the entire liner. It is concluded that the single-ring infiltration test can be used to measure the hydraulic conductivity of clay liners, although it is difficult to measure hydraulic conductivities that are substantially lower than 1 x 10-7 cm/s. In addition, the field tests may take several weeks to complete.
Download or read book Assessing Frost Damage in Compacted Clay Liners written by CH. Benson and published by . This book was released on 1995 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods used to assess frost damage (here defined as a large increase in hydraulic conductivity) in compacted clay liners are reviewed and evaluated using data collected from two test pads that were instrumented and then exposed to winter weather. The methods include comparisons of measurements of either water content and dry unit weight or hydraulic conductivity made before and after winter exposure. Field and laboratory methods of assessing hydraulic conductivity are considered.
Download or read book Representative Specimen Size for Hydraulic Conductivity Assessment of Compacted Soil Liners written by CH. Benson and published by . This book was released on 1994 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: An alternative to field measurement of hydraulic conductivity is to conduct laboratory hydraulic conductivity tests on specimens large enough to simulate field-scale conditions. Laboratory tests can be performed rapidly using standard procedures and with accurate control of state of stress and gradient. The objective of this research program was to identify how large a specimen must be to yield field-scale hydraulic conductivity. This objective was accomplished through field testing, laboratory testing, and statistical modeling.
