Download or read book Evaluation of the field lateral stress of overconsolidated clays laboratory tests in a soil from the guabirotuba formation written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the available laboratory methods for the evaluation of the in situ horizontal stresses are usually applicable only to normally consolidated or slightly overconsolidatedsoils. The assessment of the in situ effective stresses state of rigid, overconsolidated soils, and consequently of their stress-strain performance, involves a considerable degree of uncertainty due to the difficulty in the determination of the field lateral stresses . This thesis presents the results of an experimental study performed in the laboratory to gather information on compressibility and undrained stress-strain characteristics, and to determine the in situ effective lateral stress of a soil from the Guabirotuba Formation, at the Curitiba Sedimentary Basin, in the South of Brasil. The first stage of the study comprised characterization tests, mineralogical analysis and electronic microscopy evaluations. After the physical characterization of the material, it was carried out the study on the stress-strain-strength behaviour through undrained triaxial tests and oedometric tests with constant rate of deformation. Unweathred and latherized soil samples from the Guabirotuba formation were used in such investigations. As the methodologies presented in the literature are not appropriate for rigid, overconsolidated soils, a new experimental technique for the determination of the in situ lateral stress was proposed. The proposed method is based on the concept of yield surfaces. The stress history of a soil is related to its stress-strain behaviour and, therefore, can be inferred through monitoringchanges of the soil rigidity under a given stress path. Following the proposed methodology, stress-path controlled triaxial tests with internal measurement of axial strains were performed in undisturbed samples of the Guabirotuba Formation, providing an assessment of the field lateralstress of the material.
Download or read book The Behavior of Normally Consolidated and Heavily Overconsolidated Clays at Low Effective Stress written by Harcharan Singh and published by . This book was released on 1971 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Laboratory Stress Strain Testing of Geomaterials written by R. Kuwano and published by Routledge. This book was released on 2018-04-24 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: A discussion of developments in the measurement and interpretation of advanced laboratory stress-strain testing of geomaterials. It includes a collection of case studies which apply the test results and is based on the activities of the technical committee No 29 of the ISSMGE.
Download or read book Geotechnical Aspects of Stiff and Hard Clays written by Raj P. Khera and published by . This book was released on 1986 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Strength of undisturbed Clay Determined from Undrained Tests written by Charles Cushing Ladd and published by . This book was released on 1963 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Testing for Evaluation of Stress Strain Behavior of Clays written by Yudhbir and published by . This book was released on 1980 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A technique to predict the stress-strain behavior of clays along various stress paths is presented. The experimental results of stress-controlled triaxial pure shear and consolidation tests conducted on normally consolidated and lightly overconsolidated samples are given, and a method to evaluate the parameters required for prediction by the proposed technique is discussed. Comparison between experimental and predicted stress-strain behavior of normally consolidated and lightly overconsolidated samples along stress paths shows that the technique predicts the behavior quite well.
Download or read book A Laboratory Investigation of Lateral Stresses During Consolidation of San Francisco Bay Mud written by John Ivor Duval and published by . This book was released on 1994 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Role of Lateral Stress in Slope Stability of Stiff Overconsolidated Clays and Clayshales written by Jane-Fu Jeff Yang and published by . This book was released on 1987 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Techniques to Evaluate and Remediate the Slope Stability in Overconsolidated Clay written by Herman Peiffer and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this chapter, the origin and remediation of an important sliding in the overconsolidated Boom Clay in Kruibeke (Belgium) is discussed. Local and environmental factors caused an unstable slope about 30 m deep, A larger sensitivity to erosion resulted finally in the instability of the slope. Because of the formation of fine cracks in the soil there was a possibility for the water to penetrate in the clay close to the surface, resulting in the presence of higher water pressures. Also, the presence of the excavator on top of the slope during exploitation had an important impact on the stress state of the soil. Both an analytical and numerical approach were used to estimate the factor of safety. Because of the change of the soil characteristics, the factor of safety decreases, which can be estimated through a numerical analysis (using the Strength Reduction Method). This chapter also discussed the applied techniques for the remediation using numerical analysis. Also, the importance of the field test is discussed. An integrated approach, using numerical analysis and field tests in combination, is capable of predicting the instability. This approach can also be used to evaluate the stability of the slope after remediation.
Download or read book Characterization of Expansive Clay Behavior Using Centrifuge and Field Evaluations written by Christian Philip Armstrong and published by . This book was released on 2018 with total page 1108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Subsequent to the development of a centrifuge-based test methodology at the University of Texas at Austin, an extensive research program was conducted to quantify the parameters that govern the swelling behavior of expansive soils and to correlate field measurements of heave and moisture fluctuations with predictions from laboratory testing. The overall research was grouped into five self-contained research components. The first research component examined the effect of the initial conditions in centrifuge soil samples on the magnitude and time-history of swelling. The centrifugation of soil specimens was found to not affect the magnitude of swelling, further validating the centrifuge technique as practical and accurate. The second research component examined the effect of soil fabric on the swelling of laboratory-reconstituted and field-sampled clay specimens. Soil fabric was found to affect the time-history of swelling for laboratory-reconstituted specimens and to affect both the time-history and magnitude of swelling for field-sampled specimens. These results can be attributed to the field-sampled specimens containing a higher amount of peds and micro-void features, as revealed using scanning electron microscope micrographs. These micro-void features are removed during soil homogenization in the laboratory-reconstituted samples. The third research component examined the heterogeneity on a regional and local scale of two clay soils commonly found in Central Texas. The results indicated that soil samples derived from geologically older parent material tended to swell more than soils derived from geologically younger parent material and that the method of soil sampling affected the magnitude of swelling. The fourth research component examined the field behavior at a site involving an expansive soil subgrade and was instrumented using moisture content and suction sensors. Moisture fluctuations were found to be significant regardless of the pavement surface, and soil-water retention curves were found not to vary significantly with depth. The heave measured at the site was less than that predicted by centrifuge test results due to volumetric strains and desiccation cracks. The final research component examined the large-scale swelling behavior of a column test, prepared to represent a field site. Results from the large column test were compared to the heave predicted using centrifuge test results and the previous field site. The large column was found to behave similarly to the predictions from centrifuge test results, but the infiltration occurred over a longer time frame than the field site. The difference in infiltration rates between the large column and field site was attributed to desiccation cracking at the field site. Overall, the five research components involving expansive soil behavior indicate that the field monitored swelling can be predicted using laboratory centrifuge tests when properly accounting for initial conditions, soil fabric, and spatial variability.
Download or read book Removal of Cementation Bonds in Stressed Overconsolidated Clays written by FJ. Griffiths and published by . This book was released on 1988 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soils develop cementation during and after formation because of the effects of stress, time, and environment. The effects of cement removal on the change of state of soil under stress are discussed in this paper. The change in the state of stiff, overconsolidated, cemented clay under stress is reflected by void ratio change when the cementation bonds are removed. The observed increases in void ratio have been attributed to the latent physico-chemical behavior of the clay. The consolidation process is restrained during both deposition and subsequent stress history once clays are cemented. Upon further loading, clays with cement bonds removed follow the e-log ? paths predicted for the uncemented state of the same soil both for normally and overconsolidated stress conditions.
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 In Situ Testing in Geomechanics written by Fernando Schnaid and published by CRC Press. This book was released on 2009-01-13 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Demanding a thorough knowledge of material behaviour and numerical modelling, site characterisation and in situ test interpretation are no longer just basic empirical recommendations. Giving a critical appraisal of the understanding and assessment of the stress-strain-time and strength characteristics of geomaterials, this book explores new interpretation methods for measuring properties of a variety of soil formations. Emphasis is given to the five most commonly encountered in situ test techniques: standard penetration tests cone penetration tests vane test pressuremeter tests dilatometer tests Ideal for practising engineers in the fields of geomechanics and environmental engineering, this book solves numerous common problems in site characterisation. It is also a valuable companion for students coming to the end of their engineering courses and looking to work in this sector.
Download or read book Expansive Soils written by Amer Ali Al-Rawas and published by Taylor & Francis. This book was released on 2006-06-08 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expansive Soils provides the reader with easy and specific access to problems associated with expansive soils, characterisitics and treatment, and evaluation and remediation. Set up with contributions from worlwide expert, this main reference guide is intended for engineers, researchers and senior students working on soil
Download or read book Desiccation in Clay Soils written by Construction Research Communications Ltd and published by . This book was released on 1996 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Desiccation in clay soils can result in shrinkage of the soil and subsidence of the ground; this may lead to damage to buildings. As the soil re-hydrates, it can swell, resulting in ground heave; this may also cause damage to buildings. In many ground investigations, it is important to establish the extent and depth of any desiccation but this is not always easy. This Digest describes the most commonly used techniques for detecting desiccation and gives guidance on how to use the results of some of these techniques to estimate heave potential.
Download or read book Fundamentals of Soil Behavior written by James K. Mitchell and published by . This book was released on 1993 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explains the factors which determine and control the engineering properties of soils--particularly volume change, deformation, strength and permeability. New to this edition: expanded coverage of residual and tropical soils, environmental aspects of soil behavior, material on partly saturated soils, revised treatment of direct or coupled hydraulic, chemical, thermal and electrical flows through soil.
Download or read book Deep Foundations on Bored and Auger Piles BAP III written by W. Haegeman and published by CRC Press. This book was released on 2020-09-29 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text presents findings from the 3rd International Geotechnical Seminar, held in Ghent, Belgium. Topics include: American experiences with large diameter bored piles; case histories; static, dynamic and pile integrity testing; and installation parameters and capacity of screwed piles.
