Download or read book Characterization of the Swelling Properties of Highly Plastic Clays Using Centrifuge Technology written by Jorge G. Zornberg and published by . This book was released on 2009 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Implementation of Centrifuge Testing for Swelling Properties of Highly Plastic Clays written by Jorge G. Zornberg and published by . This book was released on 2013 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel centrifuge-testing device was developed for characterization of expansive soils, which are the source of major pavement design and maintenance problems across the state. Specifically, testing protocols were developed for use of a small centrifuge device to provide direct measurement of the vertical swelling of clays. In this test, soil samples are subjected to water infiltration during a comparatively short testing period. The centrifuge approach is well suited for pavement design because it provides not only one data point for a single normal stress but the entire relationship between vertical strains and vertical stresses. This feature represents a significant advantage over conventional swelling tests, which are prohibitively long; in addition, each conventional test provides the vertical strain for one vertical stress. Consequently, this approach is particularly well suited for use with the Potential Vertical Raise (PVR) approach. The objective of this project is to quantify the benefits and implement the new centrifuge technology for characterization of expansive clays in Texas. This research team will achieve this objective by implementing the laboratory procedure developed as part of Research Project 0-6048 using multiple clay sources, developing a spreadsheet with swelling curves (vertical strain versus normal stress) for relevant high-plasticity clays in Texas, incorporating the use of swelling curves obtained using centrifuge technology into the PVR methodology, and developing training material that includes examples of practical problems for calculation of the PVR using actual swelling curves and actual subgrade profiles.
Download or read book Characterization of the Swelling Potential of Expansive Clays Using Centrifuge Technology written by Jeffrey Albin Kuhn and published by . This book was released on 2010 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: The characterization of the swell potential of expansive clay is complicated by the fact that traditional swell testing methods require an excessive amount of time for specimens to swell to their maximum heights. As a result, the practicing engineer has typically referred to correlations between swell potential and index properties rather than directly measuring swelling in a laboratory experiment. The purpose of this study is to evaluate an alternate testing method using a geotechnical centrifuge in an attempt to decrease the time required to evaluate the swell potential of expansive clays so that expermientally obtained swelling properties may be obtained within a reasonable time period. This study includes an experimental program involving a series of tests in which compacted clay specimens are flown in a cetrifuge and their heights are monitored as water infiltrates into them.
Download or read book Characterization of the Swelling Behavior of Expansive Clays Using Centrifuge Technology written by Nicolas Alejandro Rivas and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental techniques with emphasis in centrifuge testing were implemented to characterize the swelling behavior of expansive clays. This research consisted in three self-contained sections related to the study of different aspects of expansive clays. The first research component focused on the implementation of a qualitative mineralogy analysis performed using x-ray diffraction to determine the main clay minerals in an expansive soil. The analysis was performed on the clay-sized fraction of the soil and samples with preferential and random orientation were used in the analysis. Vacuum filtration was used to produce oriented samples in order to maximize the intensity of the diagnostic basal spacing of the clay minerals, and samples were subjected to different treatments to produce changes in the basal spacing or crystalline structure of the clay minerals to facilitate their identification. The second research component examined the effect of the coarse fraction on the swelling characteristics of expansive soils using a centrifuge-based approach. Vertical strains at the end of primary swelling were evaluated for different proportions of coarse fraction by volume. It was found that the magnitude of vertical strains at the end of primary swelling decreased with increasing coarse fraction. It was concluded that the swelling depended uniquely on the ratio between the volume of soil solids of the fine fraction and the volume of voids. Additionally, when correcting the initial void ratio of the specimens to account for this, the relationship between vertical strains at the end of primary swelling and initial void ratio for the soil mixtures defines a unique linear trend with the baseline material. The third research component examined the potential vertical rise at three field sites in Central Texas. Method 6048-A was applied to evaluate the PVR of three field sites using direct measurements of the swelling characteristics of soils sampled at each location. Project-specific data was generated in a relatively short time using this centrifuge-based method. The results obtained demonstrated the need for testing of project-specific samples, as a significant variation in PVR was observed in Site 2 and 3 between boring locations, while less variation between borings was found in Site 1
Download or read book Evaluation of the Rate of Secondary Swelling in Expansive Clays Using Centrifuge Technology written by Jasaswee Triyambak Das and published by . This book was released on 2014 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expansive soils are characterized as having high amount of clay minerals such as smectite, which lead to swelling during wet seasons by absorbing water and shrinking during dry seasons owing to moisture loss by evapotranspiration. The soil volumetric changes due to moisture fluctuations cause extensive damage to civil engineering structures, namely pavements, retaining walls, low rise buildings and canals founded on such soils. The primary swelling portion of the swell curve has been studied in significant details in previous studies. However, there is a dearth of literature concerning the secondary swelling phenomenon in expansive clays, which has also been observed in experimental studies. While it may be argued that the magnitude of secondary swelling is significantly less as compared to primary swelling, the characterization of the rate of secondary swelling is relevant for fully characterizing the swell potential of the soil. The rate of secondary swelling has been used to predict the long-term swelling of expansive soils. Conventional laboratory swell tests may take over a month for specimens to demonstrate secondary swelling behavior. A centrifuge based method has been recently developed at The University of Texas at Austin to achieve this objective in multiple specimens, and within less than a day. The effects of soil fabric, soil type, relative compaction, molding water content, gravitational gradient, and infiltrating fluid, on the rate of secondary swelling, are thoroughly investigated in this thesis. Four different expansive clays found widely in and around Texas, namely - Eagle Ford Clay, Tan Taylor Clay, Black Taylor Clay and Houston Black Clay, have been used in the study. Based on this extensive experimental evaluation, it may be concluded that secondary swelling behavior could be explained by flow processes associated with the bimodal pore size distribution in expansive clays. The rate of secondary swelling was found to increase with increasing molding water content and increasing compaction dry unit weight. The experimental results revealed that clays with a flocculated structure (compacted dry of optimum) demonstrate rapid primary swelling but exhibit less swelling in the secondary region, as compared to clays with a dispersed structure (compacted wet of optimum). The slope of secondary swelling showed a decline with increasing gravitational gradient. The rate of secondary swelling showed evidence of upward trend with an increase in the plasticity index and clay fraction of the soil. It was observed that soils which exhibit higher primary swelling also demonstrate higher secondary swelling.
Download or read book Proceedings of the 5th International Young Geotechnical Engineers Conference written by IOS Press and published by IOS Press. This book was released on 2013-08-20 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geotechnical engineers are at work worldwide, contributing to sustainable living and to the creation of safe, economic and pleasant spaces to live, work and relax. With increased pressure on space and resources, particularly in cities, their expertise becomes ever more important. This book presents the proceedings of the 5th iYGEC, International Young Geotechnical Engineers' Conference, held at Marne-la-Vallée, France, from 31 August to 1 September 2013. It is also the second volume in the series Advances in Soil Mechanics and Geotechnical Engineering. The papers included here cover topics such as laboratory and field testing, geology and groundwater, earthworks, soil behavior, constitutive modeling, ground improvement, earthquake, retaining structures, foundations, slope stability, tunnels and observational methods. The iYGEC conference series brings together students and young people at the start of their career in the geotechnical professions to share their experience, and this book will be of interest to all those whose work involves soil mechanics and geotechnical engineering. The cover shows Dieppe harbour breakwater project, Louis-Alexandre de Cessart, 1776-1777. © École Nationale des Ponts et Chaussées.
Download or read book From Research to Applied Geotechnics written by N.P. López-Acosta and published by IOS Press. This book was released on 2019-11-26 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first Pan-American Conference on Soil Mechanics and Geotechnical Engineering (PCSMGE) was held in Mexico in 1959. Every 4 years since then, PCSMGE has brought together the geotechnical engineering community from all over the world to discuss the problems, solutions and future challenges facing this engineering sector. Sixty years after the first conference, the 2019 edition returns to Mexico. The XVI PCSMGE 2019 conference was held in Cancun, Mexico, from 17 – 20 November 2019. This book presents the plenary lectures from the conference, delivered by distinguished geotechnical engineers of international renown. Experience and youth combine in this special publication, which includes the 9th Arthur Casagrande lecture, the plenary lecture of the ISSMGE President, 3 Bright Spark lectures, and the manuscripts of the 13 invited lecturers of practically all the technical sessions at the XVI PCSMGE 2019. Topics cover both research and applied geotechnics, including recent developments in geotechnical engineering. Representing a valuable reference for engineering practitioners and graduate students, and helping to identify new issues and shape future directions for research, the book will be of interest to all those working in the field, involved in soil mechanics and geotechnical engineering.
Download or read book Hydro mechanical Characterization of Unsaturated Clays Using Centrifuge Technology written by Gastón Quaglia and published by . This book was released on 2017 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Fabric on the Swelling of Highly Plastic Clays written by Christian Philip Armstrong and published by . This book was released on 2014 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expansive soils are extremely problematic in transportation projects, and significant research has been done into examining the effect of moisture content changes and index properties on the swelling of soils. However, little has been reported on the effect of soil structure, or fabric, on swelling. The purpose of this study is to examine the effect of the soil fabric on swelling while, at the same time, validating a new set-up for a centrifuge testing program developed over the course of the project to allow for testing of undisturbed specimens. Testing to examine fabric was performed using two methods at the same effective stress, the conventional swelling test, ASTM D4546, and a new double infiltration approach in a centrifuge, on specimens of the Cook Mountain clay which were either compacted in the testing set-up or trimmed into cutting rings from soil compacted via ASTM D698, the Standard Proctor test. Specimens were compacted either dry of optimum to create a flocculated soil structure or wet of optimum to create a dispersed soil structure. Specimens were tested at their as-compacted moisture content or at a moisture conditioned moisture content to remove the effect of the initial moisture content. The results show that soils with a dispersed structure tended to swell more, over a longer time frame, and with a higher amount of secondary swelling in relation to soils with a flocculated structure when tested using the same initial moisture content. The strong influence of the initial moisture content on swelling was also verified. Further, soil specimens prepared at a comparatively high dry density for a given fabric and initial moisture content were found to swell more than soils prepared at a comparatively low dry density. The new centrifuge set-up, involving submerged specimens, was validated and was found to produce similar swelling results as those obtained from the ASTM D4546 tests. In addition, the new centrifuge approach was found to be more expeditious and results in less secondary swelling than the conventional ASTM approach.
Download or read book Free Energy in Expansive Clays written by Calvin Russell Blake and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expansive clays are common throughout the world and are responsible for significant damage to pavements and other lightly loaded structures. While many of the fundamental properties of clay minerals are well-known, several challenges still exist in the characterization of laboratory swelling and field moisture content, in addition to the expense of mitigation once a swelling problem has been identified. While soil index properties play an important role in cost-effective identification of a swelling problem, traditional swell test methods have historically been time-consuming to complete properly, making it difficult to obtain ample data, especially in large projects spanning multiple soil types. In addition, the result of a swelling test is a strain referenced to the initial density conditions of testing, and because the density itself depends on moisture, a swell test may only be as applicable as the initial moisture content was representative of the critical field case. Furthermore, field validations of structural distress caused by swelling clays necessarily require measurements of the moisture regime contributing to the volume change if lessons are to be drawn between the causes and effects of swelling. The challenge with accurate electronic moisture measurements in highly plastic clay soils is a thermodynamic one, and temperature effects can completely dominate the measurement. Finally, swelling mitigation strategies must comprehend the swelling strains expected with the treatment if a cost-effective design is to be produced. This dissertation treats each of these issues in order. First, the fundamental link between swelling and water content will be framed as a volumetric response to an effective confining stress, with the soil suction playing a critical role in the initial effective stress. Second, the temperature dependence observed in electrical time-domain reflectometry measurements will also be shown to be fundamentally related the soil suction. Third, the impact of lime treatment on clay swelling will be shown to correspond to the suppression of the diffuse double layer surrounding the clay particles
Download or read book Geotechnical Abstracts written by and published by . This book was released on 1992 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transportation Research Record written by and published by . This book was released on 1990 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Permeability and Groundwater Contaminant Transport written by and published by ASTM International. This book was released on 1981 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Science of Clays written by Swapna Mukherjee and published by Springer Science & Business Media. This book was released on 2013-10-09 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an attempt to provide a comprehensive and coherent description of three widely separated aspects of clays: the science of clays; the industrial uses of clays; and the role of clays in the environment. Most of the existing literature lacks such an integrated study and this work endeavours to fill that gap. An exhaustive account of the science of clays is presented in Part I of the book, which includes the classification, origin and evolution, composition and internal structure, chemical and physical properties of clays; soil mechanics; and analytical techniques for determining clay constituents. Part II provides a comprehensive description of the applications of clays and their derivatives in various industries, while Part III describes the role of clays in the environment; the pollution caused by clay minerals; and the application of clays in order to prevent environmental hazards. A principal feature of the book is its explanation of how the structure and composition of particular clay types facilitate their specific industrial or environmental applications, thus describing the interrelationship between three widely varying aspects of clay. A number of thought-provoking questions are raised at the end of the work in order to leave readers with a better insight in this regard.
Download or read book Advances in Transportation Geotechnics IV written by Erol Tutumluer and published by Springer Nature. This book was released on 2021-09-16 with total page 1059 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents selected papers presented during the 4th International Conference on Transportation Geotechnics. The papers address the geotechnical challenges in design, construction, maintenance, monitoring, and upgrading of roads, railways, airfields, and harbor facilities and other ground transportation infrastructure with the goal of providing safe, economic, environmental, reliable and sustainable infrastructures. This volume will be of interest to postgraduate students, academics, researchers, and consultants working in the field of civil and transport infrastructure.
Download or read book Transactions of the 11th International Conference on Structural Mechanics in Reactor Technology written by Heki Shibata and published by . This book was released on 1991 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unsaturated Soil Mechanics written by Ning Lu and published by John Wiley & Sons. This book was released on 2004-05-20 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unsaturated Soil Mechanics is the first book to provide a comprehensive introduction to the fundamental principles of unsaturated soil mechanics. * Offers extensive sample problems with an accompanying solutions manual. * Brings together the rapid advances in research in unsaturated soil mechanics in one focused volume. * Covers advances in effective stress and suction and hydraulic conductivity measurement.
