Download or read book Permeability Tests in Rigid Wall Permeameters written by RP. Chapuis and published by . This book was released on 2004 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper documents a method to determine the degree of saturation, Sr, of a soil specimen at any time during a rigid-wall permeameter test. This method first indicates that the tested specimen usually is not fully saturated. Then it is used to prove that the usual test termination criterion based on equality of inflow and outflow volumes may be misleading. Examples are provided where the two volumes were equal within 1 %, whereas Sr increased from 80 to 100 % and k increased by a factor of 4. Without knowing the technique to determine the Sr value at any time, the test would have been stopped prematurely and would have given some k(Sr) value for an unknown Sr with the risk of misinterpreting this result as k(Sr = 100 %). New equations for gas transfer between water and gas bubbles are also established and experimentally verified for specimens permeated with either deaired water or water over-saturated with air.

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 Book excerpt: ASTM D2434, Standard Test Method for Permeability of Granular Soils (Constant Head) (Withdrawn 2015) , and ASTM D5856, Standard Test Method for Measurement of Hydraulic Conductivity of Porous Material Using a Rigid-Wall, Compaction-Mold Permeameter , are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 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 Large Scale Laboratory Permeability Testing of a Compacted Clay Soil written by CD. Shackelford and published by . This book was released on 1991 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constant-head permeability (hydraulic conductivity) tests were performed on samples of a compacted clay soil using a 0.914 by 0.914 by 0.457-m (3 by 3 by 1.5-ft) large-scale, double-ring, rigid-wall permeameter. A naturally occurring silty clay soil was used for the permeability tests. The soil was separated into five different fractions representing five different ranges in precompaction clod sizes. Soil from each of the soil fractions was used for soil specimens. The soil for the large-scale permeameter was compacted in two 7.62-cm (3-in) lifts. Small-scale, constant-head permeability tests also were performed on soil specimens compacted into standard Proctor molds (9.44 × 10-4 m3). Comparison of the results from the two different scales of permeameters indicated that, in all cases, the permeability for a given soil fraction was higher in the large-scale permeameter than it was in the small-scale permeameter. In addition, the permeability for all soil fractions measured in the large-scale permeameter ranged from 0.6 to 2.4 orders of magnitude higher than the value measured in the small-scale permeameter. As a result of the permeability tests performed in this study, there appears to be a scale effect associated with laboratory permeability testing, especially when a significant proportion of the soil being tested consists of precompaction clod sizes which are large relative to the size of the permeameter. The scale effect in this study is thought to be due to the relationship between the compactive effort and the different degrees of confinement associated with the different scales of permeameters. The implication of the study is that a more realistic evaluation of the fieldmeasured permeability of a compacted clay soil may be possible in the laboratory if the permeameter is sufficiently large to test a representative sample of soil.

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 An Introduction to Seepage Failure Modes in Embankment Dams for Professional Engineers written by J. Paul Guyer, P.E., R.A. and published by Guyer Partners. This book was released on 2022-05-20 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introductory technical guidance for civil engineers interested in seepage failure analysis of embankment dams. Here is what is discussed: 1. DEFINITION OF TERMS, 2. SEEPAGE-RELATED ISSUES AND FAILURE MODES, 3. KEY DATA FOR SEEPAGE EVALUATION.

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 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 Evaluation and Remediation of Low Permeability and Dual Porosity Environments written by Martin N. Sara and published by ASTM International. This book was released on 2002 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydraulic Barriers in Soil and Rock written by Arnold Ivan Johnson and published by ASTM International. This book was released on 1985 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hazardous and Industrial Solid Waste Testing written by James K. Petros and published by ASTM International. This book was released on 1985 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hard Rock Mine Reclamation written by Bruno Bussière and published by CRC Press. This book was released on 2020-12-09 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hard rock mines have significant effects on the territories where they operate, through both infrastructure construction as well as resource use. Due to their extractive activities, these mines store large quantities of wastes at the surface, which can be both physically and chemically unstable. Reclamation aims to return a mine site to a satisfactory state, meaning that the site should not threaten human health or security, should not generate in the long term any contaminant that could significantly affect the surrounding environment, and should be aesthetically acceptable to communities. This book focuses on the reclamation of waste storage areas, which constitute the main source of pollution during and after mine operations, and especially issues with acid mine drainage and neutral contaminated drainage. Features: Provides fundamental information and describes practical methods to reclaim mine-waste facilities Compares the different methods and illustrates their application at sites through case studies Identifies new reclamation issues and proposes solutions to address them Presents existing and new technologies to reclaim mine waste disposal areas from hard rock mines in different climatic conditions Integrates reclamation into mine operations and long term performance of techniques used through an interdisciplinary approach With mine site reclamation a young and still emerging science, the training needs for professionals and students working in this field are huge. This book is written from an engineering point of view and in it the authors identify new reclamation issues and propose well-tested as well as innovative approaches to addressing them. Students in graduate programs focused on mines and the environment as well as professionals already working in departments related to mine site reclamation will find this book to be a valuable and essential resource.

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 Engineering Geology and the Environment written by Paul G. Marinos and published by CRC Press. This book was released on 1997 with total page 1168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Procedure and Equipment Factors Affecting Permeability Testing of a Bentonite Sand Liner Material written by TB. Edil and published by . This book was released on 1985 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents the findings of an investigation regarding the effects of procedural and equipmental factors on the laboratory measurement of permeability of a bentonite-sand liner. In the experimental program, permeability tests were performed on compacted specimens of a bentonite-sand mixture to study the effect of (1) permeameter type (rigid- versus flexible-wall permeameters), (2) back pressure application, and (3) hydraulic gradient magnitude on the measured permeabilities. The liner material used in the tests was a mixture of 90% P20-R30 Ottawa sand and 10% bentonite clay. Water was used to prepare the specimens and as the permeant. Specimens were prepared by compaction at moisture contents exceeding optimum using the standard proctor method. A pressure of 380 kPa was used in the tests involving back pressure. The low and high hydraulic gradients used were nominally 29 and 290, respectively. Prior to the termination of a test, a red indicator was passed through the permeameters under the high gradient. The specimens were dissected and inspected after the test for the identification of flow areas and channels.

Download or read book Hazardous Solid Waste Testing written by Conway and published by ASTM International. This book was released on 1983-09 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Geotechnical Papers of James K Mitchell written by James K. Mitchell and published by ASCE Publications. This book was released on 2001-01-01 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sponsored by the Geo-Institute of ASCE. This collections contains 35 key papers by James K. Mitchell during his extraordinary career as a geotechnical engineer.Ø In addition to teaching, Mitchell's career encompassed geotechnical projects ranging from research on hazardous waste landfill stability at Kettleman Hills in California, to lunar soil analysis for NASA Apollo Missions, to working with the Mayor of San Francisco following the 1989 Loma Prieta Earthquake. He was elected to the National Academy of Engineering and the National Academy of Science. Topics include: experimental and analytic studies of soil behavior related to geotechnical and geo-environmental problems; soil improvement and ground reinforcement, physicochemical phenomena in soils, the stress-strain time behavior of soils, in situ measurement of soil properties, and mitigation of ground failure risk during earthquakes. ASCE's Engineering Classics series presents selected papers of lasting importance by eminent engineers who have made outstanding contributions to their field.