Download or read book Saturated Hydraulic Conductivity of Poorly Graded Sands with Non Plastic Silt Using a Flexible Wall Permeameter written by Thanabalasingam Sathees and published by . This book was released on 2006 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Issues in Global Environment Biology and Geoscience 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 1120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Global Environment: Biology and Geoscience: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Global Environment—Biology and Geoscience. The editors have built Issues in Global Environment: Biology and Geoscience: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Global Environment—Biology and Geoscience in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Global Environment: Biology and Geoscience: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

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 the Hydraulic Conductivity of Gravels Using a Laboratory Permeameter and Silty Sands Using Field Testing with Observation Wells written by Aaron Judge and published by . This book was released on 2013 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new laboratory permeameter was developed for measuring the hydraulic conductivity of gravels ranging from 0.1 to 2 m/s. The release of pneumatic pressure applied to the test specimen induces an underdamped oscillatory response of the water level above the permeameter, similar to an underdamped in situ slug test response in monitoring wells. A closed form model was derived to calibrate the hydraulic minor losses in the permeameter and the hydraulic conductivity of the specimen by performing tests without and with a specimen. The majority of each test series performed on individual specimens produced hydraulic conductivity values within 10% of the average, which is very small for such a measurement. Tests were performed using the permeameter on a collection of subrounded and angular gravels prepared to measured grain size distributions and porosities. The surface area was determined by evaluating the shape and angularity using a method developed in this research and these parameters were used with the measured tortuosity and hydraulic conductivity, to back calculate the packing factor of the Kozeny-Carman equation. The results show that the packing factor for the gravels and materials tested is proportional to the tortuosity cubed. These results provide a valuable update to the Kozeny-Carman equation for predicting the hydraulic conductivity of gravels. Field slug interference tests were performed in pairs of monitoring wells installed at the same elevation in a floodplain deposit of silty sand in Dedham MA. Slug tests were performed in one of the wells while the response was monitored simultaneously in both wells. The measured responses were both analyzed by modifying the KGS model of Hyder et al. (1994) to consider the wellbore storage and filter packs effects. This modification was found to produce estimates of hydraulic conductivity based on the slugged well response that compared well with that estimated based on the observation well's response. Calibrated hydraulic conductivities for the pairs of wells tested ranged from 4x10-6 to 1.5x10-5 m/s and specific storage ranged from 2x10-5 to 7x10-4 m-1.

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 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 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 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 Thesis M S Civil Engineering New Mexico State University 2008 written by Sittampalam Sathiskumar and published by . This book was released on 2008 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of the Velocity head Permeameter to Determine the Saturated Hydraulic Conductivity and for Septic System Site Evaluation written by Kevin Jay Rose and published by . This book was released on 1988 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measuring Saturated Hydraulic Conductivity of Soils written by American Society of Agricultural Engineers. Drainage Research Committee and published by . This book was released on 1962 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laboratory Evaluation of the Constant Rate of Strain and Constant Head Techniques for Measurement of the Hydraulic Conductivity of Fine Grained Soils written by Amy Lynn Adams and published by . This book was released on 2011 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis evaluates the constant rate of strain and constant head techniques for measurement of the hydraulic conductivity of fine grained soils. A laboratory program compares hydraulic conductivity measurements made using both measurement techniques on a total of 12 specimens. Both resedimented and intact materials covering a wide range of plasticity are investigated. Specific material types include Boston Blue Clay, San Francisco Bay Mud, Maine Clay, Ugnu Clay and Kaolinite. Constant rate of strain (CRS) and constant head tests were conducted in a standard Trautwein CRS device modified to allow control of the base pore pressure for constant head testing. A flexible wall permeameter device was used to perform constant head hydraulic conductivity testing on two specimens; this allowed for comparison with the constant head measurements made in the CRS device. A bottom seating error was found in the CRS device. Bottom seating error occurs during set up when the top of the base porous stone is not flush with the bottom of the rigid specimen ring, causing a gap to form between the specimen and the porous stone. A bottom seating error translates into a strain error, which affects both the measured CRS compression and hydraulic conductivity results. Bottom seating error can be avoided using a modified set up procedure. Void ratio errors are sometimes noted between the void ratio measured in the CRS device and that measured upon removal from the CRS device. These errors are likely resultant from specimen swelling following load removal. Based on comparison to the results of an interlaboratory study into the reproducibility of the saturated hydraulic conductivity measured in a flexible wall permeameter, the CRS and constant head techniques were found to measure the same hydraulic conductivity. This conclusion is independent of specimen origin, i.e. resedimented or intact. The CRS and constant head techniques measure the same average hydraulic conductivity even when non uniformities are present, provided the non uniformities are continuous and oriented perpendicular to the axial loading direction.

Download or read book Method Development for Determining the Hydraulic Conductivity of Fractured Porous Media written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Plausible, but unvalidated, theoretical model constructs for unsaturated hydraulic conductivity of fractured porous media are currently used in Performance Assessment (PA) modeling for cracked saltstone and concrete (Flach 2011). The Nuclear Regulatory Commission (NRC) has expressed concern about the lack of model support for these assumed Moisture Characteristic Curves (MCC) data, as noted in Requests for Additional Information (RAIs) PA-8 and SP-4 (Savannah River Remediation, LLC, 2011). The objective of this task was to advance PA model support by developing an experimental method for determining the hydraulic conductivity of fractured cementitious materials under unsaturated conditions, and to demonstrate the technique on fractured saltstone samples. The task was requested through Task Technical Request (TTR) HLW-SSF-TTR-2012-0016 and conducted in accordance with Task Technical & Quality Assurance Plan (TTQAP) SRNL-TR-2012-00090. Preliminary method development previously conducted by Kohn et al. (2012) identified transient outflow extraction as the most promising method for characterizing the unsaturated properties of fractured porous media. While the research conducted by Kohn et al. (2012) focused on fractured media analogs such as stacked glass slides, the current task focused directly on fractured saltstone. For this task, four sample types with differing fracture geometries were considered: 1) intact saltstone, 2) intact saltstone with a single saw cut, smooth surface fracture, 3) micro-fractured saltstone (induced by oven drying), and 4) micro-fractured saltstone with a single, fully-penetrating, rough-surface fracture. Each sample type was tested initially for saturated hydraulic conductivity following method ASTM D 5084 using a flexible wall permeameter. Samples were subsequently tested using the transient outflow extraction method to determine cumulative outflow as a function of time and applied pressure. Of the four sample types tested, two yielded datasets suitable for analysis (sample types 3 and 4). The intact saltstone sample (sample type 1) did not yield any measureable outflow over the pressure range of the outflow test (0-1000 cm H2O). This was expected because the estimated air entry pressure for intact saltstone is on the order of 100,000 cm H2O (Dixon et al., 2009). The intact saltstone sample with a single saw cut smooth surface fracture (sample type 2) did not produce useable data because the fracture completely drained at less than 10 cm H2O applied pressure. The cumulative outflow data from sample types 3 and 4 were analyzed using an inverse solution of the Richard's equation for water flow in variably saturated porous media. This technique was implemented using the computer code Hydrus-1D (Šimůnek et al., 2008) and the resulting output included the van Genuchten-Mualem water retention and relative permeability parameters and predicted saturated hydraulic conductivity (Van Genuchten, 1980; Van Genuchten et al., 1991). Estimations of relative permeability and saturated conductivity are possible because the transient response of the sample to pressure changes is recorded during the multi-step outflow extraction test. Characteristic curves were developed for sample types 3 and 4 based on the results of the transient outflow method and compared to that of intact saltstone previously reported by Dixon et al. (2009). The overall results of this study indicate that the outflow extraction method is suitable for measuring the hydraulic properties of micro-fractured porous media. The resulting cumulative outflow data can be analyzed using the computer code Hydrus-1D to generate the van Genuchten curve fitting parameters that adequately describe fracture drainage. The resulting characteristic curves are consistent with blended characteristic curves that combine the behaviors of low pressure drainage associated with fracture flow with high pressure drainage from the bulk saltstone matrix.

Download or read book Calculation of the Saturated Hydraulic Conductivity of Fine grained Soils written by American Society of Civil Engineers (ASCE) and published by . This book was released on 2017 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Standard ANSI/ASCE/EWRI 65-17 provides guidelines for calculating the saturated hydraulic conductivity (Ksat), permeability, and porosity of fine-grained soils.

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 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 An Assessment of Selected Factors which Influence the Hydraulic Conductivity of Fine grained Soils written by Steven Michael Bruer and published by . This book was released on 1994 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: