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 Permeability Testing with Flexible Wall Permeameters written by DE. Daniel and published by . This book was released on 1984 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The equipment and testing procedures used at The University of Texas at Austin for measuring the hydraulic conductivity of fine-grained soil with flexible-wall permeameters are described. The permeability cell is similar to a triaxial cell; it has interchangeable base pedestals to accomodate specimens of various diameters, is equipped with double drainage lines to the top and bottom of the test specimen, and can accomodate a differentially acting pressure transducer to measure head loss across the soil specimen. An air-over-liquid interface is maintained in devices called "accumulators." Stainless steel accumulators designed with transparent sight tubes offer excellent resistance to corrosion, are convenient to use, and can be used with a wide range in flow rates. The permeability tests are normally performed using back pressure. Care is taken to be certain that flow is steady state and that the soil is permeated long enough for the influent liquid to pass through the soil and to appear in the effluent liquid in full concentration. When clays are permeated with dilute chemicals that are adsorbed by the soil, testing times on the order of months or years may be required to achieve full breakthrough of the permeant liquid. Use of large hydraulic gradient and excessive effective confining pressure are sometimes difficult to avoid but are two of the most important sources of potential error.
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 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 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 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 Vadose Zone Hydrology written by Daniel B. Stephens and published by CRC Press. This book was released on 2018-02-06 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vadose Zone Hydrology describes the elements of the physical processes most often encountered by hydrogeologists and ground-water engineers in their vadose zone projects. It illustrates the application of soil physics to practical problems relevant to the characterization and monitoring of the vadose zone. It includes an introduction to physical processes, including basic flow theory, and provides examples of important field-scale processes that must be recognizable by hydrogeologists. Considerable attention is given to the concepts of recharge, including how it is most accurately evaluated in the vadose zone. Field and laboratory methods for characterizing hydraulic properties in the vadose zone are also covered, and case studies illustrating these methods are provided. New and emerging technologies for monitoring the vadose zone, particularly for the purpose of detecting contaminants, are highlighted. In the last section of the book, additional case studies are presented, demonstrating applications related to seepage detection, landfill monitoring, and soil gas investigations. This book is written from the perspective of hydrogeologists and is designed to be directly applicable and to maintain continuity and consistency between chapters. It will be an invaluable primer for environmental or geotechnical consultants, regulators, or students who have no prior formal academic training in unsaturated flow concepts. Because the text contains some of the latest advances in this field, it will be an excellent reference for geologists and engineers currently working on problems of vadose zone hydrology.
Download or read book Standard Test Methods for Determining the Effect of Freeze Thaw on Hydraulic Conductivity of Compacted or Intact Soil Specimens Using a Flexible Wall Permeameter written by and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Standard Test Method for Determining the Effect of Freeze Thaw on Hydraulic Conductivity of Compacted or Intact Soil Specimens Using a Flexible Wall Permeameter written by and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Flexible Wall Permeameter for the Determination of the Water Permeability Function in Unsaturated Soils written by M. P. H. Moncada and published by . This book was released on 2011 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the development of a suction controlled flexible wall permeameter for the direct determination of the water permeability function in unsaturated soils. The new permeameter works with applied constant head or constant rate of flow, i.e., the common steady-state techniques. Total volume change of soil specimens during the test are monitored using a high resolution electronic scale. Numerical simulations were performed to evaluate the influence of factors such as flow velocity and matric suction distribution within the specimen and effects of sample height on such factors. Analyses of tests conducted on two tropical soil samples are used to evaluate conventional proposals for the determination of the water permeability function. It is shown that such proposals do not apply in the case of the materials tested and solutions to that are put forwards.
Download or read book Standard Test Method for Measurement of Hydraulic Conductivity of Porous Material Using a Rigid wall Compaction mold Permeameter written by ASTM Committee D-18 on Soil and Rock and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Apparatus Induced Error in Hydraulic Conductivity Measurement Using a Lucite Fixed Wall Permeameter written by AT. Yeung and published by . This book was released on 2005 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydraulic conductivity is the most variable parameter in geotechnical engineering. Although accurate measurement of hydraulic conductivity of fine-grained soil is not an easy task, it is often required to satisfy the legitimate requirements of various agencies regulating the design, construction, and operation of compacted clay liners. Results are sensitive to the experimental apparatus and testing procedure used for the measurement. As the flow volumes being measured are very small, any minute leakage of permeant during the test will significantly affect the results obtained. The quantification of a significant unexpected loss of permeant through fixed wall permeameters made of Lucite is documented and discussed in this paper.
Download or read book How to Improve the Quality of Laboratory Permeability Tests in Rigid Wall Permeameters A Review written by Robert P. Chapuis and published by . This book was released on 2020 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: ASTM D2434, Standard Test Method for Permeability of Granular Soils (Constant Head) (Withdrawn 2015) , and ASTM D5856, Standard Test Method for Measurement of Hydraulic Conductivity of Porous Material Using a Rigid-Wall, Compaction-Mold Permeameter , are used to measure the saturated hydraulic conductivity, K sat , of soil specimens in rigid-wall permeameters (RWPs). Several laboratory conditions and settings explain why the tests do not give K sat values but unsaturated hydraulic conductivity, K ( S r ), values for a degree of saturation, S r , that is often in the 80-85 % range. It is suggested to improve ASTM D2434 and ASTM D5856 by adding two requirements: (1) use a watertight-and-airtight RWP (a control method is provided), and (2) use a mass-and-volume method to obtain the true S r value of the tested specimen. To illustrate potential detrimental impacts of current standards, the article describes a case where sand was planned to be used as a filter layer for a solid waste project. Large quantities of sand had been delivered at the construction site. The K sat value of the sand, as compacted, had to exceed 10 -4 m/s to satisfy a bylaw. To prove this, two laboratories followed ASTM D2434 for their tests but found K values of 5-8×10 -5 m/s. The project engineers asked the authors to make verifications. The prior tests were redone and yielded similar K values. However, it was found that the real S r value was close to 80 % instead of being assumed to be 100 %. Other tests were performed after using vacuum and deaired water in a watertight-and-airtight permeameter: the specimens reached S r =100 % and gave K sat values of about 2×10 -4 m/s, 3-4 times higher than initial tests. As a result, the already delivered sand satisfied the bylaw condition and there was no need to return large quantities of sand already delivered, to purchase a new type of sand after having done laboratory tests, and to have a time delay in construction, all these items having a high economic impact.
Download or read book Air entry Permeameter Method of Measuring Hydraulic Conductivity of Soil in Situ written by Abdul Satar Younis Aldabagh and published by . This book was released on 1968 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Apparatus for Measuring Hydraulic Conductivity of Undisturbed Soil Samples written by K. E. Wit and published by . This book was released on 1967 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Manual of Soil Laboratory Testing Soil Classification and Compaction Testing written by K. H. Head and published by John Wiley & Sons. This book was released on 1980-07-16 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Geotechnical Engineering written by and published by . This book was released on 1996 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
