Download or read book Development of Constitutive Models for Linear and Nonlinear Shear Modulus and Material Damping Relationships of Uncemented Soils written by Yaning Wang (Ph. D.) and published by . This book was released on 2018 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt: For many decades, hundreds of soil samples recovered from North America and other parts of the world have been tested in the Soil and Rock Dynamics (SRD) Laboratory at The University of Texas at Austin using combined resonant column and torsional shear (RCTS) equipment. Dynamic soil property relationships determined in this study include: (1) linear relationships of log G[subscript max] - log [sigma]0 and log D[subscript min] - log [sigma]0, and (2) nonlinear relationships of G/G[subscript max] - log [gamma] and D - log [gamma]. These relationships are important in geotechnical design, especially for geotechnical earthquake engineering and soil dynamics. More recently, higher resolution measurements have been made over shear strains ranging from about 1×10−6 to 0.3 %. Most recently, measurements of the initiation of pore-water pressure generation in nearly to saturated poorly-graded sands and low-plasticity silts have been conducted during torsional shear (TS) testing. A significant database has been developed involving all types of uncemented soil specimens tested in the SRD Laboratory since the late 1980's. The effects of soil type, index properties, density, confining state and strain level on the dynamic properties have been quantified through multivariable regression analyses performed on the database. Four sets of empirical models for log G[subscript max] - log [sigma]0, G/G[subscript max] - log [gamma], log D[subscript min] - log [sigma]0 and D - log [gamma] relationships are presented in this study. These models are composed of simple equations that incorporate the key parameters controlling linear soil behavior as well as nonlinear soil behavior. The process used to develop the parameters in the models employed a residual analysis procedure in a staged manner. Both the mean values of the empirical models and the uncertainty associated with these values are presented. Those empirical models show significant improvements in accuracy and applicable range compared to previous models. The application ranges of these models and sparse portions of the associated database are also discussed for the sake of appropriate utilization and future updates. The influence of number of loading cycles, confining pressure and soil type (sand or low-plasticity silt) on the initiation of pore-water pressure generation during TS testing are briefly discussed. A preliminary model for the r[subscript u] - log [gamma] relationship is presented. This model focuses on determination of the threshold strain at which pore pressure generation is triggered, [gamma][subscript t][superscript pp], and the early stages leading towards soil liquefaction.

Download or read book Practice of Constitutive Modelling for Saturated Soils written by Zhen-Yu Yin and published by Springer Nature. This book was released on 2020-09-11 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the development of a constitutive modeling platform for soil testing, which is one of the key components in geomechanics and geotechnics. It discusses the fundamentals of the constitutive modeling of soils and illustrates the use of these models to simulate various laboratory tests. To help readers understand the fundamentals and modeling of soil behaviors, it first introduces the general stress–strain relationship of soils and the principles and modeling approaches of various laboratory tests, before examining the ideas and formulations of constitutive models of soils. Moving on to the application of constitutive models, it presents a modeling platform with a practical, simple interface, which includes various kinds of tests and constitutive models ranging from clay to sand, that is used for simulating most kinds of laboratory tests. The book is intended for undergraduate and graduate-level teaching in soil mechanics and geotechnical engineering and other related engineering specialties. Thanks to the inclusion of real-world applications, it is also of use to industry practitioners, opening the door to advanced courses on modeling within the industrial engineering and operations research fields.

Download or read book Constitutive Modeling of Soils and Rocks written by Pierre-Yves Hicher and published by John Wiley & Sons. This book was released on 2013-03-01 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title provides a comprehensive overview of elastoplasticity relating to soil and rocks. Following a general outline of the models of behavior and their internal structure, each chapter develops a different area of this subject relating to the author's particular expertise. The first half of the book concentrates on the elastoplasticity of soft soils and rocks, while the second half examines that of hard soils and rocks.

Download or read book Modelling of Soil Behaviour with Hypoplasticity written by David Mašín and published by Springer. This book was released on 2018-12-12 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explains the hypoplastic modelling framework. It is divided into two parts, the first of which is devoted to principles of hypoplasticity. First, the basic features of soil’s mechanical behaviour are introduced, namely non-linearity and asymptotic properties. These features are then incorporated into simple one-dimensional hypoplastic equations for compression and shear. Subsequently, a hypoplastic equivalent of the Modified Cam-Clay model is developed in 2D space using stress and strain invariants to demonstrate key similarities and differences between elasto-plastic and hypoplastic formulations. Lastly, the mathematical structure of hypoplastic models is explained by tracing their historical development, from the early trial-and-error models to more recent approaches. In turn, Part II introduces specific hypoplastic models for soils. First, two reference models for sand and clay are defined. After summarising their mathematical formulations, calibration procedures are described and discussed. Subsequently, more advanced modelling approaches are covered: the intergranular strain concept incorporating the effects of small strain stiffness and cyclic loading, viscohypoplasticity for predicting rate effects, soil structure to represent structured and bonded materials and soil anisotropy. The book concludes with a description of partial saturation and thermal effects: topics that are increasingly important to the disciplines of energy and environmental geotechnics. Selecting a constitutive model and its parameters is often the most important and yet challenging part of any numerical analysis in geotechnical engineering. Hypoplasticity involves a specific class of soil constitutive models, which are described in detail here. The book offers an essential resource, both for model users who need a more advanced model for their geotechnical calculations and are mainly interested in parameter calibration procedures, and for model developers who are seeking a comprehensive understanding of the mathematical structure of hypoplasticity.

Download or read book Damping Capacity of Soil During Dynamic Loading written by Behzad Rohani and published by . This book was released on 1972 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modeling of Soil Constitutive Relationship written by Qingyang Ren and published by Springer Nature. This book was released on 2021-09-01 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book adopts numerical method to model soil constitutive relationship while it abandons the traditional idea of looking for plastic potential as the only way to model. Firstly, the triaxial compression tests of expansive soil, sand and clay under different stress paths are introduced; then the elastoplastic constitutive equations of expansive soil, sand and clay under various stress paths are established by numerical modeling method; finally, the constitutive equations are embedded in the finite element program and verified by comparing the finite element calculation results of the triaxial test soil samples with the corresponding test results. The modeling obtains high accuracy.

Download or read book Developments in Dynamic Soil Structure Interaction written by Polat Gülkan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the last couple of decades it has been recognized that the foundation material on which a structure is constructed may interact dynamically with the structure during its response to dynamic excitation to the extent that the stresses and deflections in the system are modified from the values that would have been developed if it had been on a rigid foundation. This phenomenon is examined in detail in the book. The basic solutions are examined in time and frequency domains and finite element and boundary element solutions compared. Experimental investigations aimed at correlation and verification with theory are described in detail. A wide variety of SSI problems may be formulated and solved approximately using simplified models in lieu of rigorous procedures; the book gives a good overview of these methods. A feature which often lacks in other texts on the subject is the way in which dynamic behavior of soil can be modeled. Two contributors have addressed this problem from the computational and physical characterization viewpoints. The book illustrates practical areas with the analysis of tunnel linings and stiffness and damping of pile groups. Finally, design code provisions and derivation of design input motions complete this thorough overview of SSI in conventional engineering practice. Taken in its entirety the book, authored by fifteen well known experts, gives an in-depth review of soil-structure interaction across a broad spectrum of aspects usually not covered in a single volume. It should be a readily useable reference for the research worker as well as the advance level practitioner. (abstract) This book treats the dynamic soil-structure interaction phenomenon across a broad spectrum of aspects ranging from basic theory, simplified and rigorous solution techniques and their comparisons as well as successes in predicting experimentally recorded measurements. Dynamic soil behavior and practical problems are given thorough coverage. It is intended to serve both as a readily understandable reference work for the researcher and the advanced-level practitioner.

Download or read book Towards A Unified Soil Mechanics Theory The Use of Effective Stresses in Unsaturated Soils Revised Edition written by Eduardo Rojas and published by Bentham Science Publishers. This book was released on 2018-08-08 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the application of the effective stress concept, the strength and volumetric behavior of saturated materials was clearly understood. For the case of unsaturated materials, a universally accepted effective stresses equation is still under debate. However, the use of the effective stress concept to develop constitutive models for unsaturated soils is becoming increasingly popular not only because the hydro-mechanical coupling observed in these materials is implicit in the formulation but also because simpler and more precise models can be established. Towards A Unified Soil Mechanics Theory demonstrates that the same strength and volume change equations used in saturated soil mechanics can be used for the case of unsaturated soils. In other words, the constitutive models developed for saturated soils can be used for unsaturated materials once the effective stress equation has been defined. In this book, an analytical equation for the effective stress for unsaturated soils is established. This equation requires the knowledge of the superficial area of solids affected by the capillary phenomenon. In other words, we need to know how water distributes in the pores of the soil. This distribution can be modeled using a solid-porous model built on a regular network. However, the size of the network required to correctly simulate the structure of a small soil sample cannot be managed with a common PC. For that reason, a probabilistic porous-solid model is developed. This model uses the pore size distribution in the form of a probabilistic function which in addition to the Laplace equation and the principle of continuity can be expressed as the probability of a pore of certain size to be filled or dry at suction during a wetting or drying path, respectively. In this way, the soil-water retention curves can be simulated and the effective stress at any suction during wetting or drying processes can be determined. Based on this approach, it is shown that unsaturated soils behave under the same principles for strength and volumetric behavior as saturated soils. This revised edition brings additional information about an elastoplastic framework for expansive soils, hydro-mechanical coupling and a fully coupled model. The additional chapters also cover the experimental parameters used to derive the models. An updated set of references and a list of abbreviations is also included in this edition. Towards A Unified Soil Mechanics Theory paves the way for a universal theory of soil mechanics. The volume will be a valuable reference to civil engineers, earth scientists and hydrologists interested in soil mechanics at both academic and professional levels.

Download or read book Investigation of Ground Shock Effects in Nonlinear Hysteretic Media written by Ivan Nelson and published by . This book was released on 1968 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: A historical outline of mathematical models used previously to represent soil and rock behavior in ground shock computations at low pressure levels is presented. The problems and deficiencies of these early approaches are discussed. Subsequently, two types of models are developed; one a plastic model in which the yield condition depends on the mean stress and in which different variable bulk moduli are used in loading and unloading. The second type of model, called the 'variable bulk moduli model, ' has variable shear as well as moduli, but no explicit yield condition. The behavior of both types of model in uniaxial strain and triaxial compression tests is examined. (Author).

Download or read book Development of a Constitutive Model for Resilient Modulus of Cohesive Soils written by Dong Gyou Kim and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The objective of this study was to evaluate existing constitutive models currently used by State Department of Transportations (DOTs) and to develop an improved model for predicting resilient modulus (Mr) of cohesive soils from simple soil properties typically measured in DOT laboratories in preference to expensive and complex Mr laboratory testing. The data set used consisted of cohesive soils typical of those used for subgrades in Ohio. Thirteen representative cohesive soils representing A-4, A-6, and A-7-6 soil types collected from road construction sites across Ohio, were tested in the laboratory to determine their basic engineering properties. Mr tests were conducted at three different moisture contents (dry of optimum moisture content, optimum moisture content, and wet of optimum moisture content). Additional tests were performed on samples compacted to optimum conditions but allowed to fully saturate. Mr predicted from six existing models studied showed wide scatter and poor correlation with the measured Mr. An improved constitutive model was developed to account for the effects on Mr of the stress state of the soil and its engineering properties obtained from simple laboratory tests. While most of the existing models investigated in this study significantly overestimated the Mr of a cohesive soil, the proposed model predictions are close to the experimental values and are in most cases a slight underestimation. This implies that Mr values predicted by the proposed model are generally slightly conservative, and can be safely used in the design of flexible pavements to be built on cohesive soils. The proposed model can be a useful and reliable tool for estimating Mr of cohesive subgrade soils using basic soil properties and the stress state of the soil.

Download or read book The SMP Concept Based 3D Constitutive Models for Geomaterials written by Hajime Matsuoka and published by CRC Press. This book was released on 2014-04-21 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cam-Clay model is a fundamental constitutive model in soil mechanics, but is only suitable for normally consolidated clay under triaxial compression stress states. The SMP failure criterion is the most reasonable three-dimensional extension of the Mohr-Coulomb failure criterion from the point of view of its physical meaning, mathematical expres

Download or read book Effects of Cementation on the Linear and Nonlinear Shear Modulus and Material Damping of Intact Sand Specimens written by Ian Vernon Trahms Johnson and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report written by and published by . This book was released on 1960 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Field Measurements of the Linear and Nonlinear Shear Moduli of Cemented Alluvium Using Dynamically Loaded Surface Footings written by Kwangsoo Park and published by . This book was released on 2010 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, a research effort aimed at development and implementation of a direct field test method to evaluate the linear and nonlinear shear modulus of soil is presented. The field method utilizes a surface footing that is dynamically loaded horizontally. The test procedure involves applying static and dynamic loads to the surface footing and measuring the soil response beneath the loaded area using embedded geophones. A wide range in dynamic loads under a constant static load permits measurements of linear and nonlinear shear wave propagation from which shear moduli and associated shearing strains are evaluated. Shear wave velocities in the linear and nonlinear strain ranges are calculated from time delays in waveforms monitored by geophone pairs. Shear moduli are then obtained using the shear wave velocities and the mass density of a soil. Shear strains are determined using particle displacements calculated from particle velocities measured at the geophones by assuming a linear variation between geophone pairs. The field test method was validated by conducting an initial field experiment at sandy site in Austin, Texas. Then, field experiments were performed on cemented alluvium, a complex, hard-to-sample material. Three separate locations at Yucca Mountain, Nevada were tested. The tests successfully measured: (1) the effect of confining pressure on shear and compression moduli in the linear strain range and (2) the effect of strain on shear moduli at various states of stress in the field. The field measurements were first compared with empirical relationships for uncemented gravel. This comparison showed that the alluvium was clearly cemented. The field measurements were then compared to other independent measurements including laboratory resonant column tests and field seismic tests using the spectral-analysis-of-surface-waves method. The results from the field tests were generally in good agreement with the other independent test results, indicating that the proposed method has the ability to directly evaluate complex material like cemented alluvium in the field.

Download or read book Finite Deformation Dynamic Analysis and Constitutive Modeling of Non cohesive Soils for Liquefaction Problems written by Majid Taghizadeh Manzari and published by . This book was released on 1994 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Constitutive Models written by Jerry A. Yamamuro and published by Amer Society of Civil Engineers. This book was released on 2005-01 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: GSP 128 contains papers by 19 prominent constitutive modelers presented at the Geo-Frontier Conference, held in Austin, Texas, January 24-26, 2005.

Download or read book Constitutive Relations for Soils written by G. Gudehus and published by . This book was released on 1984 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: