Download or read book Monotonic Cyclic and Postcyclic Shear Behavior of Low plasticity Silt written by Shuying Wang and published by Springer. This book was released on 2018-01-24 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the main research findings on monotonic, cyclic and postcyclic shear behavior of low-plasticity. Drawing on the low-plasticity silt from the Mississippi River Valley, it determines that the silt’s critical state line can be changed due to liquefaction, and thus offers valuable insights and reference data for further investigations on soil mechanics and engineering applications to verify the above research findings. Low-plasticity silt with a plasticity index of less than 10, though commonly found around the world, nonetheless differs greatly from sand and clay in terms of its shear behavior. Failure to take into account the differences in shear characteristics between silt, clay and sand will lead to overconservative designs of offshore structures. In particular, dynamic loading from earthquakes, trains and ocean waves can set off the liquefaction of low-plasticity silt, and with it, major disasters and losses of properties. Additionally, some civil infrastructures have failed not only due to cyclic loading during an earthquake, but also due to reduction of shear strength or stiffness after that.
Download or read book Postcyclic Behavior of Low plasticity Silt written by Shuying Wang and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Liquefaction of low-plasticity silt has been reported during earthquakes in the recent past. Excess pore pressure builds up due to the dynamic loading and then dissipates. The postcyclic behavior of low-plasticity silt was investigated in this research for materials obtained from the Mississippi River Valley. The experimental program involved specimen preparation using a slurry consolidation approach. A special technique was developed for specimen movement, reducing the testing program time by half. Both static and cyclic triaxial tests were conducted to confirm the ability to prepare replica specimens. In order to characterize the monotonic behavior, triaxial tests were conducted to determine the effective friction angle, critical state line, and normalized behavior. Then specimens were subjected to cyclic loading to develop the liquefaction curve. After full liquefaction, excess pore pressure was dissipated until various reconsolidation levels. The effect of full liquefaction on the permeability and compressibility was studied. The variation in postcyclic shear strength and stiffness with reconsolidation level and the effect of apparent consolidation on shear behavior were also discussed. The critical state lines for the pre- and postliquefaction conditions were compared and found to be not parallel. After limited liquefaction, two unique conditions were tested, at no reconsolidation and at full reconsolidation. The shear strength and stiffness changed significantly at an excess pore pressure ratio greater than 0.70. The experimental program culminated with the study of the effect of plasticity on the pre- and postcyclic shear behavior. Silt-bentonite mixtures resulted in modified plasticity and the transformation from a dilative to a plastic behavior were captured at relatively low plasticity (PI> 6)--Abstract, leaf iii
Download or read book The Behavior of a Low Plasticity Silty Clay Under Conditions of Static and Cyclic Direct Simple Shear written by Mary Ellen Caves and published by . This book was released on 1991 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Undrained Cyclic Loading of Low Plasticity Silty Soils in the Pacific Northwest Using Laboratory and Field Cyclic Shear Testing written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cyclic behavior of a fine-grained low plasticity silty soil (plasticity index of approximately 15) at a site in Portland, Oregon, is characterized using a field and laboratory cyclic shear test program. The field cyclic tests were performed using the NHERI@UTexas large mobile shakers T-Rex and Rattler. The laboratory tests were performed using resonant column torsional shear and cyclic direct simple shear devices. This testing program's results were used to evaluate the soil's potential to develop excess pore water pressure with cyclic shear strains ranging from 0.00001% to 3%. The laboratory cyclic test results are compared against field cyclic test results to predict the soil's cyclic behavior during earthquakes. These data will contribute to the larger body of knowledge of the cyclic behavior of low plasticity silts. This study includes additional laboratory cyclic shear tests from the following: low plasticity silts from Longview, Washington, diatomaceous soils (high plasticity silts) obtained from Klamath Falls, Oregon, silty sands from the Columbia River Slough in Oregon, and low plasticity silt and low plasticity clay from Beaverton, Oregon. The objective of the cyclic shear tests on different soils is to understand how these soils may potentially behave in the event of a large magnitude earthquake.
Download or read book Advances in Computer Methods and Geomechanics written by Amit Prashant and published by Springer Nature. This book was released on 2020-01-14 with total page 735 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents selected papers from IACMAG Symposium,The major themes covered in this conference are Earthquake Engineering, Ground Improvement and Constitutive Modelling. This volume will be of interest to researchers and practitioners in geotechnical and geomechanical engineering.
Download or read book Innovative Earthquake Soil Dynamics written by Takaji Kokusho and published by CRC Press. This book was released on 2017-07-28 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovative Earthquake Soil Dynamics deals with soil dynamics in earthquake engineering and includes almost all aspects of soil behavior. Both generally accepted basic knowledge as well as advanced and innovative views are accommodated. Major topics are (i) seismic site amplification, (ii) liquefaction and (iii) earthquake-induced slope failure. Associated with the above, basic theories and knowledge on wave propagation/attenuation, soil properties, laboratory tests, numerical analyses, and model tests are addressed in the first part of the book. A great number of earthquake observations in surface soil deposits as well as case histories with new findings are addressed in the later chapters, together with associated laboratory test data. Most of the research results originate from Japan, which is rich in earthquake records and case histories, although mostly isolated from the outside world because of the language barrier. Another important feature characterizing this book is an energy perspective in addition to the force-equilibrium perspective, because it is the author’s strong belief that energy is a very relevant index in determining seismic failures, particularly of soils and soil structures. Innovative Earthquake Soil Dynamics is written for international readers, graduate students, researchers, and practicing engineers, interested in this field.
Download or read book Liquefaction and Postliquefaction Behavior of Low Plasticity Silts Using Cyclic Triaxial Tests written by Ali Mohammad Izadi and published by . This book was released on 2008 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A considerable amount of research has been conducted on the strength of both clays and sands, while research on low plasticity silt has been limited. the objective of this experimental study is to evaluate the cyclic behavior and liquefaction potential of low plasticity silts. The cyclic behavior of sand-like and clay-like soils have been compared to the cyclic behavior of low plasticity silts"--Abstract, leaf iii.
Download or read book Frontiers in Offshore Geotechnics III written by Vaughan Meyer and published by CRC Press. This book was released on 2015-05-15 with total page 1422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frontiers in Offshore Geotechnics III comprises the contributions presented at the Third International Symposium on Frontiers in Offshore Geotechnics (ISFOG, Oslo, Norway, 10-12 June 2015), organised by the Norwegian Geotechnical Institute (NGI). The papers address current and emerging geotechnical engineering challenges facing those working in off
Download or read book Cyclic and Post cyclic Response of Silt and Sandy Silt Soils written by Ali El Takch and published by . This book was released on 2013 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of cyclic and monotonic constant-volume ring shear tests were carried out to determine the cyclic and post-cyclic response of silts and sandy silts with 25% and 50% sand. The elastic soil behavior at very small shear strain (? 10-4%) was investigated through shear wave velocity (Vs) measurements using bender elements at vertical stresses ranging from 50 to 300 kPa, while strain-controlled constant volume cyclic ring shear tests were conducted to establish shear modulus (G) and damping ratio (D) at larger shear strain amplitudes (? 0.01%). Liquefaction and strain-softening occurred at excess pore water pressure ratios (ru) between 0.6 and 0.7 associated with cumulative shear strains of 4% to 6%, after which cyclic mobility failure ensued with very large shear strains and excess pore water pressure ratio (ru> 0.9). The test data indicated that existing field CRR-Vs1 correlations could underestimate the liquefaction resistance of soils with fine content (FC) e"50%. It is found that Vs and the maximum shear modulus (Go) significantly decrease with increasing void ratio. Vs is also found to vary with the effective overburden stress to the power of 0.31 - 0.34 for all silt and sandy silt mixes. The results show that while G decreases with increasing?, D increases with increasing? only up to?
Download or read book Direct Simple Shear Testing for Post Cyclic Degradation in Stiffness of Nonplastic Silt written by BW. Song and published by . This book was released on 2004 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using a sequential procedure of cyclic and postcyclic direct simple shear tests, the stiffness degradation characteristics of nonplastic silt are studied during and immediately after cyclic loading by direct simple shear (DSS) tests. The results from cyclic and postcyclic DSS tests were interpreted using methods modified from those adopted for cyclic and postcyclic triaxial tests. In particular, the effect of initial static shear stress (ISSS) on postcyclic behavior is considered for nonplastic silt. The findings obtained from the sequential DSS testing on nonplastic silt are: (i) during cyclic loading the tendency of the stiffness to decrease with increasing normalized pore pressure is different for plastic and nonplastic silts, (ii) since the relation between equivalent stiffness ratio and single amplitude shear strain for nonplastic silt does not filt the Hardin-Drnevich Model, new modified relation is needed, (iii) the larger the ISSS is, the faster the decrease in stiffness ratio becomes, and (iv) the decrease of stiffness ratio for nonplatic silt is less marked than that for plastic silt when plotted against the normalized pore pressure after cyclic load.
Download or read book Symmetrical and Non symmetrical Cyclic Triaxial Loading of Silt written by Gholam Moradi and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Latest Developments in Geotechnical Earthquake Engineering and Soil Dynamics written by T.G. Sitharam and published by Springer Nature. This book was released on 2021-07-01 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings together contributions from world renowned researchers and practitioners in the field of geotechnical engineering. The chapters of this book are based on the keynote and invited lectures delivered at the 7th International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. The book presents advances in the field of soil dynamics and geotechnical earthquake engineering. A strong emphasis is placed on proving connections between academic research and field practice, with many examples, case studies, best practices, and discussions on performance-based design. This volume will be of interest to research scholars, academicians and industry professionals alike.
Download or read book Instability Mechanism and Disaster Prevention of the Jointed Rockmass written by Shuren Wang and published by Frontiers Media SA. This book was released on 2024-06-13 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discontinuities such as cracks, fissures, bedding planes, etc. resulting from different geological processes are commonly found in rock masses and often play a critical role in the initiation, propagation, and coalescence of new cracks due to stress redistribution caused by engineering activities and natural disturbances. It is challenging to determine the instability mechanism of jointed rock masses but it is vital for estimating instability disasters in jointed rock engineering.
Download or read book Undrained Cyclic Shear Resistance of Low Plastic Silts written by and published by . This book was released on 2020 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: A magnitude 9 Cascadia Subduction Zone earthquake is expected to trigger widespread liquefaction in loose material in Oregon. The geotechnical engineering studies have determined that the Willamette Silts may be susceptible to liquefaction or cyclic softening, as their plasticity indices ranges between non-plastic to low plasticity. While the majority of past studies have focused on liquefaction of sand and cyclic behavior of clays, there is not enough data on the cyclic response behavior of silty soils and the liquefaction susceptibility of these soils. A research focus in the geotechnical engineering program at Portland State University revolves around is performing cyclic tests on samples obtained from regional silts to fill the gap in data, in an effort to better characterize the liquefaction susceptibility of non-plastic to low plasticity silts. The primary goal of this thesis is to study the behavior of undrained cyclic shear resistance of low plastic fine-grained soils that were extracted from Beaverton, OR. The constant volume direct simple shear test device made by GeoComp is used to test the soil samples. The critical challenge in this project was to prepare close-to-identical remolded specimens to be able to evaluate intricate differences in the cyclic behavior of silts under different loading conditions. The thesis will present the cyclic shear resistance of laboratory prepared samples and the adopted procedures to prepare identical slurry samples.
Download or read book Geo Congress 2013 Stability and Performance of Slopes and Embankments III written by Christopher L. Meehan and published by . This book was released on 2013-03-01 with total page 2280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Geotechnical Special Publication contains 229 peer-reviewed technical papers and case studies focusing on the stability, performance, and rehabilitation of slopes, embankments, and dams. Topics include: exploration and characterisation of soil and rock slopesdesign, analysis, and performance of slopesmonitoring and inspection of slopeshazard assessment and managementground improvement and stabilisation in the repair and remediation of slopes. These papers are valuable to geotechnical researchers and practicing engineers, especially those interested in the design and maintenance of slopes, embankments and dams.
Download or read book Soil Liquefaction written by Michael Jefferies and published by CRC Press. This book was released on 2006-09-04 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil liquefaction is a major concern in areas of the world subject to seismic activity or other repeated vibration loads. This book brings together a large body of information on the topic, and presents it within a unified and simple framework. The result is a book which will provide the practising civil engineer with a very sound understanding of
Download or read book The Behavior of Silt as Clay Content is Increased written by Stephen Joseph Romero and published by . This book was released on 1998 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
