Download or read book The Influence of Anisotropic Consolidation on the Strength of Clays written by Paulo Teixeira Da Cruz and published by . This book was released on 1960 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Anisotropic Versus Isotropic Consolidation in Consolidated undrained Triaxial Compression Tests of Cohesive Soils written by Frank C. Townsend and published by . This book was released on 1975 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a series of consolidated-undrained (CU) triaxial compression tests performed on normally consolidated and overconsolidated specimes of two clays consolidated both isotropically (ICU tests) and anisotropically (ACU tests) are presented and analyzed in this report. The specimens were trimmed from samples of Vicksburg Buckshot clay (LL = 57) and a clay from the East Atchafalaya Basin Protection Levee (EABPL) project area (LL = 79), both of which had been consolidated from a slurry in large-diameter consolidometers under a maximum vertical consolidation pressure of 3.0 kg/sq cm. Data presented include stress-strain curves, pore pressure observations, final water content distributions within the specimens, and shear strength envelopes based on total and effective stresses. Test results indicate that the change in volume during consolidation and the water content at the end of consolidation are not a unique function of the vertical consolidation stresses but are related to the mean effective consolidation stress. Total stress envelopes based on Taylor's method of deriving strengths of anisotropically consolidated specimens from test results obtained from isotropically consolidated specimens slightly underestimate observed values. In this context, Taylor's method is an appropriate means of predicting strengths for various K sub c ratios from conventional ICU tests. Use of hyperbolic stress-strain relationships derived from ICU tests in finite element codes for ACU conditions will lead to erroneous results. Further testing of anisotropically consolidated soils under stress systems that better simulate in situ conditions is needed.
Download or read book Effects of Anisotropic Versus Isotropic Consolidation in Consolidated Undrained Triaxial Compression Tests of Cohesive Soils written by RT. Donaghe and published by . This book was released on 1978 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: This investigation examines effects of anisotropic versus isotropic consolidation in consolidated-undrained triaxial compression tests performed on specimens of two clays consolidated from a slurry in large-diameter consolidometers. Shear strength and corresponding deformation characteristics were developed in both normally consolidated and overconsolidated ranges. Test results indicate that volume changes during consolidation are not a unique function of the major principal consolidation stress but instead are related to the mean effective consolidation stress and the deviator stress during consolidation. Consequently, for a given major principal consolidation stress, the undrained strength of anisotropically consolidated specimens is lower than that of isotropically consolidated specimens.
Download or read book A Study of the Effect of Anisotropic Consolidation on the Relationships Between Shear Strength Water Content and Effective Stresses of a Kaolinite Clay written by Mallimadugula Venkata Ratnam and published by . This book was released on 1962 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Anisotropy and Reorientation of Principal Stresses on the Shear Strength of Saturated Clay written by James Michael Duncan and published by . This book was released on 1965 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Strain Rate in Consolidated undrained Triaxial Compression Tests of Cohesive Soils written by Rául F. Esquivel-Díaz and published by . This book was released on 1970 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research in Earth Physics written by Charles Cushing Ladd and published by . This book was released on 1965 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Anisotropy and Reorientation of Principal Stresses on the Shear Strength of Saturated Clay written by James Michael Duncan and published by . This book was released on 1965 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of the investigation are to establish the fundamental nature of the anisotropy of saturated clays with respect to undrained strength, and to evaluate the practical significance of anisotropy and reorientation of the principal stresses in short-term stability problems. (Author).
Download or read book Three dimensional Experiments and Modeling of Anisotropic Clay written by Pongpipat Anantanasakul and published by . This book was released on 2011 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents the results of a research effort conducted to better understand the stress-strain, volume change, shear band formation, and strength characteristics of normally consolidated anisotropic clay under fully three-dimensional stress states. A series of consolidated drained true triaxial tests with a constant mean effective stress and constant Lode angles during shear are performed on cross-anisotropic kaolin clay. All tests are performed in a fully automated true triaxial testing apparatus. The relative magnitude of the intermediate principal stress, expressed in terms of the b-value, and initial cross-anisotropy show significant influence on the stress-strain, volume change, strength, and shear band formation characteristics of the clay. Shear bands form and appear to cause failure in all true triaxial tests performed, except in triaxial compression. The initiation and development of shear bands is observed to take place when the clay undergoes volumetric contraction. The lower strength exhibited in the shear bands is caused by alignment of the clay particles. This shear band mechanism is different from that observed in granular materials in which the lower shear strength is reached due to dilation in the shear bands. This dissertation also presents a study on the simulative capabilities of anisotropic and isotropic elasto-plastic bounding surface models under fully three-dimensional stresses. The models assume the associated plastic flow rule and are based on bounding surface elastoplasticity and the critical state theory. The predictions of the models are compared to the stress-strain, volume change, and strength characteristics observed in drained true triaxial tests with a constant effective mean stress and constant Lode angles during shear on normally consolidated anisotropic kaolin clay. The bounding surface models can predict the influence of intermediate principal stress on the behavior of the clay but with magnitudes considerably different from those observed in the experimental results. The effects of initial cross-anisotropy on the behavior of the clay, however, cannot be fully predicted by the anisotropic bounding surface model. These incapabilities are largely due to the use of associated plastic flow rule. More realistic predictions can also be obtained by incorporating a model feature that allows bifurcation from the uniform stress-strain conditions into a localized failure mode or shear bands. This dissertation also includes the details and results of a laboratory study on the influence of non-plastic silt content on the stress-strain, volume change, and strength characteristics of transition silt-clay soils. Series of one-dimensional consolidation tests, isotropic consolidation tests, and triaxial compression tests on three soils of similar base clay but different non-plastic silt contents are performed on cross-anisotropic specimens. The specimen preparation method, testing procedure, and testing conditions of each testing type are controlled to be consistent. Both vertical and horizontal specimens have been tested. It is observed that the tested silt-clay soils are less compressible with increasing silt content during one-dimensional and isotropic consolidation tests. During drained and undrained triaxial compression tests, the normally consolidated soils of the same consolidation stresses show larger values of stiffness, drained and undrained shear strengths, and slightly stronger volumetric contractive tendencies with increasing silt content. The silt-clay soils' effective strengths become more isotropic with increasing silt content. Lower possibilities of shear band initiation and development are observed in the contractive silt-clay soils with higher silt content.
Download or read book Triaxial Tests on Compacted Clays for Consolidated Undrained Conditions written by D. R. VandenBerge and published by . This book was released on 2014 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consolidated-undrained tests must be performed on compacted soils to provide undrained soil properties for embankment design scenarios, such as rapid drawdown. These soils are subject to anisotropic consolidation under field conditions. Laboratory testing of compacted clays must consider the effects of the consolidation stress system as well as the subtleties involved in testing initially unsaturated clay specimens. This study considers the effects of anisotropic consolidation on the undrained strength of a compacted lean clay. Strengths were measured using isotropically and anisotropically consolidated undrained triaxial compression tests. It was found that anisotropic consolidation has little effect on the undrained strength of compacted clay at vertical effective consolidation stresses below 50 kPa. As the consolidation stress increased, anisotropic consolidation was shown to decrease the undrained strength by 30 % at vertical effective consolidation stress of 300 kPa. It was also found that undrained strengths can increase by 50 % of more due to increases in relative compaction of a few %. Recommendations are presented for addressing the challenges of performing consolidated-undrained tests on compacted clays.
Download or read book Effect of Anisotropic Preconsolidation on the Strength Characteristics of a Normally Consolidated Clay written by Edward W. Brand and published by . This book was released on 1973 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research in Earth Physics written by Charles Cushing Ladd and published by . This book was released on 1967 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Sampling and Disturbance on the Strength of Soft Clays written by Harry Bolton Seed and published by . This book was released on 1964 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: The laboratory procedure most commonly used for strength determination is the triaxial compression test. The relationship between data obtained with this test procedure and the in-situ strength of a soil under comparable deformation conditions (i.e., axially symmetric strain and same orientation of principal stresses) will be the subject of this report. (Author).
Download or read book The Anisotropic and Isotropic Strength Behavior of an Illitic Clay written by Miles M. O'Brien and published by . This book was released on 1977 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cause and the nature of anisotropy in a cohesive soil was investigated by direct shear and triaxial compression tests. Laboratory techniques and procedures used to prepare isotropic clay samples are given where consolidation was accomplished under hydrostatic pressure. Direct shear tests were performed on these specimens trimmed at different inclinations to the physical horizontal from the block samples. The ratio of undrained shear strengths in any direction to shear strength in the vertical direction was found to be equal to one, proving isotropy existed. Similar tests were performed on specimens trimmed from the same clay consolidated one-dimensionally. Results from these tests showed the shear strength ratio to be maximum for specimens trimmed at 90° to the horizontal plane. In this case, the aniso- tropic characteristics were directly attributed to the sample stress history. These samples indicated preferred particle orientation. Undrained triaxial compression tests were performed on both hydrostatic and one-dimensionally consolidated samples. Triaxial test results confirmed the results of the direct shear tests and more accurately defined the stress/strength parameters. The angle between the failure plane and the test specimens axis was essentially constant and the ratio between pore water pressure at failure and the mean consolidation stress remained a constant. For each maximum consolidation stress, pore pressure was isotropic, but in all cases was higher for hydrostatically prepared samples. The hydrostatic method of preparing isotropic test specimens was effective and produced reliable results.
Download or read book A comparison of the effects of isotropic and anisotropic consolidation on the shear behaviour of a clay written by Victor Albert Sowa and published by . This book was released on 1963 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Anisotropic Consolidation on the Creep Characteristics of Laurentian Clay written by Richard A. Sullivan and published by . This book was released on 1959 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study on Effects of Deterioration of Grains on Deformation and Strength Characteristics of Soils written by Mubashir Aziz and published by GRIN Verlag. This book was released on 2011-12-29 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doctoral Thesis / Dissertation from the year 2010 in the subject Engineering - Geotechnology, course: Civil Engineering, language: English, abstract: With growing infrastructure developments in hilly areas and due to economical constraints of using locally available rockfill materials for construction of embankments, practicing engineers must be acquainted with geotechnical response of non-conventional granular soils. These materials are most likely to disintegrate with time due to physical and chemical weathering. In general, the laboratory investigations on durability characteristics of such materials are only made through simple slaking tests. However, studies examining the effects of slaking-induced disintegration of soil grains on the geotechnical engineering analysis and design parameters are rather limited. This is essentially due to the reason that the grains of standard laboratory sands are mostly durable and hence, the stress-strain response is considered to be unaffected by the presence of water. In order to explore the possible effects of deterioration of soil grains on static and dynamic properties of granular soils, a series of consolidated drained torsional shear tests on various crushed soft rocks were performed under saturated and dry conditions and compared with a well reported Toyoura silica sand consisting of durable grains. Due to the sensitivity of crushed rockfill to deteriorate upon water-submergence, test under dry conditions represented the response of a soil with intact grains, whereas a similar test under saturated condition simulated the potential reduction in strength and stiffness of the soil with time. From the grain size distributions determined after each test, a degradation index was defined to quantify the degree of disintegration of grains. Strength and deformation properties determined from monotonic as well as cyclic shear tests were then compared with this index. Possible correlations of water-induced deterioration of soil g
