Download or read book Constitutive Modelling of Soils and Fibre reinforced Soils written by Thomas Bower and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Constitutive Model for Fiber reinforced Soils written by Cheng-Wei Chen and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fiber inclusion to improve the properties of compacted soil is becoming increasingly common in geotechnical engineering projects. However, the technique requires extensive testing on soil and fiber samples before it can be implemented. Although research performed over the last few decades has evaluated certain fiber-reinforced soil properties and formations, the development of constitutive models for fiber-reinforced soil has lagged. This dissertation aims to minimize testing requirements for fiber-reinforced specimens and thereby to encourage the implementation of fiber-reinforced soils in engineering. Extensive testing on unreinforced and reinforced silty and Ottawa sand specimens was performed to develop and to validate a constitutive model for predicting the stress strain-volume-pore pressure response of fiber-reinforced soils. Results showed that the effective friction angle and cohesion intercept increased significantly in consolidated undrained CU) and consolidated-drained (CD) triaxial compression tests for both fiber-reinforced silty sand and Ottawa sand. The shear strength parameters of fiber-reinforced silty sand and Ottawa sand are strain dependent so more shear strain was needed to mobilize fiber resistance for specimens consolidated at higher effective stresses. Moreover, the laboratory results suggested that fiber-reinforcement provides both a deviatoric (q[function]) and a hydrostatic (p[function]) contribution to the stresses in the specimens. However, the hydrostatic contribution of fibers varied according to different soil types and loading conditions. The proposed constitutive model to predict the mechanical properties of fiber-reinforced soils is based on superposition of the response of unreinforced soil and the response due to fibers. Key assumptions in the model include: (1) fibers are uniformly distributed in the specimens. (2) [integral] mob accounts for the reductions in fiber strain due to relative slip between the fibers and the soil, and varies with effective consolidation stress, soil types, and loading conditions, (3) yielding is considered, (4) shear distortion ([for all] is equal to triaxial shear strain ([for all]q), (5) the total axial strain in the fibers ([for all] t) is equal to 0.25 times axial strain plus 1.68 times volumetric strain from tests on unreinforced specimens, and (6) the initial p[function] 0 and q[function] 0 are used to account for the compaction, extrusion, and consolidation process. The model was found to be capable of reproducing the deviatoric stress well for all reinforced silty sand and Ottawa sand. The predicted pore pressure and volumetric strain were all in a close agreement with the observed behavior up to large strains for both soils. However, the predicted volumetric strain behavior shows some tendency to over-predict the dilatancy of the reinforced silty sand specimens consolidated less than 20-psi (140-[kappa]Pa). The predictions in fiber deviatoric and hydrostatic stresses in CU tests matched reasonably well and followed the same trends as the measured behavior, except for specimens consolidated at higher effective stresses. In CD tests, the deviatoric and hydrostatic stresses matched reasonably well and mimicked the measured behavior, but tended to deviate slightly from the observed response at large strains.

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 Development of a Constitutive Model for Fiber reinforced Soils written by Ricardo J. Romero and published by . This book was released on 2003 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the research was to develop a model to predict the effective stress-strain-pore pressure-volume change behavior of fiber-reinforced soils from the superposition of the response of unreinforced soil and the response attributed to fibers. Consolidated-undrained triaxial compression tests (CU tests) and consolidated-drained triaxial compression tests (CD tests) were performed on comparable fiber-reinforced and unreinforced soil specimens. The results of these tests indicate that the inclusion of fibers significantly improves the strength of soils, and increases the peak strength as well as the strain to failure. Fiber-reinforcement increased both the cohesion intercept ( c ' ) and the effective stress friction angle ([straight phi] ' ). It was found that c ' and [straight phi] ' are strain dependent. Reinforced specimens sheared under undrained conditions exhibited higher pore pressure than unreinforced specimens. Under drained conditions, reinforced specimens showed significantly less dilation than unreinforced specimens, which is in agreement with the response observed in undrained tests. It was postulated that these responses are caused by an "internal confining stress" provided by the fibers. Based on the results of laboratory tests, a model is proposed to predict the stress-strain-pore pressure-volume change behavior of fiber-reinforced soils. The key components of the model include mechanism to account for initial stresses in the fibers induced during compaction, saturation, and consolidation; stresses induced during shearing of the specimens; stresses due to volume changes in the specimen; and, finally, pullout or yielding of the fibers. The proposed model is capable of reproducing very well the stress-strain behavior. Pore pressures and volume changes are well predicted at shear strains less than 10 percent and under consolidation pressures less than 550 kPa. However, pore pressures and volume changes are not well predicted at larger strains.

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 Fundamentals of Fibre Reinforced Soil Engineering written by Sanjay Kumar Shukla and published by Springer. This book was released on 2017-01-16 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended to serve as a one-stop reference on fibre-reinforced soils. Over the past 30-35 years, the engineering behaviour of randomly distributed/oriented fibre-reinforced soil, also called simply fibre-reinforced soil, has been investigated in detail by researchers and engineers worldwide. Waste fibres (plastic waste fibres, old tyre fibres, etc.) create disposal and environmental problems. Utilization of such fibres in construction can help resolve these concerns. Research studies and some field applications have shown that the fibres can be utilized in large quantities in geotechnical and civil engineering applications in a cost-effective and environmentally friendly manner. This book covers a complete description of fibres, their effects when included within a soil or other similar materials such as the fly ash, and their field applications. It gives a detailed view of fibre-reinforced soil engineering. The book will be useful to students, professional, and researchers alike, and can also serve as a text for graduate coursework and professional development programs

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 Constitutive Modeling of Geomaterials written by Qiang Yang and published by Springer Science & Business Media. This book was released on 2012-08-22 with total page 779 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Second International Symposium on Constitutive Modeling of Geomaterials: Advances and New Applications (IS-Model 2012), is to be held in Beijing, China, during October 15-16, 2012. The symposium is organized by Tsinghua University, the International Association for Computer Methods and Advances in Geomechanics (IACMAG), the Committee of Numerical and Physical Modeling of Rock Mass, Chinese Society for Rock Mechanics and Engineering, and the Committee of Constitutive Relations and Strength Theory, China Institution of Soil Mechanics and Geotechnical Engineering, China Civil Engineering Society. This Symposium follows the first successful International Workshop on Constitutive Modeling held in Hong Kong, which was organized by Prof. JH Yin in 2007. Constitutive modeling of geomaterials has been an active research area for a long period of time. Different approaches have been used in the development of various constitutive models. A number of models have been implemented in the numerical analyses of geotechnical structures. The objective of the symposium is to provide a forum for researchers and engineers working or interested in the area of constitutive modeling to meet together and share new ideas, achievements and experiences through presentations and discussions. Emphasis is placed on recent advances of constitutive modeling and its applications in both theoretic and experimental aspects. Six famous scholars have been invited for the plenary speeches of the symposiums. Some prominent scholars have been invited to organize four specialized workshops on hot topics, including “Time-dependent stress-strain behavior of geomaterials”, “Constitutive modeling within critical state soil mechanics”, “Multiscale and multiphysics in geomaterials”, and “Damage to failure in rock structures”. A total of 49 papers are included in the above topics. In addition, 51 papers are grouped under three topics covering “Behaviour of geomaterials”, “Constitutive model”, and “Applications”. The editors expect that the book can be helpful as a reference to all those in the field of constitutive modeling of geomaterials.

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 Proceedings of GeoShanghai 2018 International Conference Fundamentals of Soil Behaviours written by Annan Zhou and published by Springer. This book was released on 2018-05-10 with total page 1026 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the second volume of the proceedings of the 4th GeoShanghai International Conference that was held on May 27 - 30, 2018. The book, entitled “Fundamentals of Soil Behaviours”, presents the recent advances and technology in the understanding and modelling of fundamentals of soil’s behaviours. The subject of this book covers a wide range of topics related to soil behaviours in geotechnical engineering, geoenvironmental engineering and transportation engineering. The state-of-the-art theories, methodologies and findings in the related topics are included. This book may benefit researchers and scientists from the academic fields of soil and rock mechanics, geotechnical engineering, geoenvironmental engineering, transportation engineering, geology, mining and energy, as well as practical engineers from industry. Each of the papers included in this book received at least two positive peer reviews. The editors would like to express their sincerest appreciation to all of the anonymous reviewers all over the world, for their diligent work.

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 Modeling of Soils an Overview written by Atef Fatthy Saleeb and published by . This book was released on 1982 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Stress Strain Behavior Measurement Modeling and Analysis written by Hoe I. Ling and published by Springer Science & Business Media. This book was released on 2007-11-28 with total page 989 pages. Available in PDF, EPUB and Kindle. Book excerpt: The material in this work is focused on recent developments in research into the stress-strain behavior of geomaterials, with an emphasis on laboratory measurements, soil constitutive modeling and behavior of soil structures (such as reinforced soils, piles and slopes). The latest advancements in the field, such as the rate effect and dynamic behavior of both clay and sand, behavior of modified soils and soil mixtures, and soil liquefaction are addressed.

Download or read book Vibrations of Soils and Foundations written by Frank Edwin Richart and published by Prentice Hall. This book was released on 1970 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: For graduate students in soil dynamics with a background in statics and elementary dynamics.

Download or read book Constitutive Modelling of Unsaturated Soils written by Patrick Arnold and published by . This book was released on 2007 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Incremental Constitutive Model for Geofiber Reinforced Soil written by Kexin Ma and published by . This book was released on 2004 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geofiber reinforced soil (GFRS) is highly inhomogeneous with its two constituents: geofiber and soil. The overall behaviors of GFRS are determined by its characteristics such as the properties of constituents, geometry of geofiber, content and distribution of geofibers in the reinforced soil, and their interactions. Because the macroscopic approach alone is unable to respond to the effect of local characteristics, a micromechanical approach is desirable for the analysis of GFRS. In this dissertation, an incremental constitutive model considering microscopic damage was developed in which applied mean-field theory is used in each steps of the analysis. The roles of soil and geofiber in the reinforced soil, the interface between the geofiber and the soil, and the fiber-matrix interaction were analyzed for both local and global responses. An interface evolutionary law was introduced into the model and was used with each step to obtain the total stiffness of GFRS, which is a function of micro-structural parameters and the applied macro strain. A series of torsional shear tests were conducted to provide data on the properties of the soil and to verify the validity and accuracy of the proposed model. Three types of samples, classified in terms of the weight of their geofiber contents of 0.0%, 0.2% and 0.5%, were investigated in these tests. They were also subjected to a variety of loading frequencies ranging from 0.01 Hz to 5.0Hz. The shear modulus of soil as a function of shear strain amplitude and loading frequency was obtained by using curve-fitting techniques in the analysis of test results. Results from the torsional shear tests indicate that the presence of geofiber leads to higher stiffnesses of the reinforced soil and the higher geofiber content is more effective than the lower fiber content. It also indicates that the shear stress increases in a nonlinear manner with an increase in shear strain. Nonlinear behavior is more pronounced in reinforced soil than that in unreinforced soil. The shear modulus always increases with an increase in loading frequency in this test range. When comparing the results determined by the experiments and those determined by theoretical predictions, good agreement was found regarding the torsional shear behaviors of GFRS. -- Abstract.

Download or read book A New Method for Numerical Analysis of Reinforced Soil written by Yu-xin Jie and published by . This book was released on 2012 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are two general approaches to the analysis of reinforced soil. One is to deal with the soil and the reinforcement separately, assuming that they interact with each other through friction on the interface between them. The other is to consider the reinforced soil as an anisotropic homogeneous composite, such that the forces of interaction between soil and reinforcement material become internal, something that does not appear in calculations of the stress and deformation of the composite. In this paper, a new method is proposed for the analysis of reinforced soil. The basic principle of this method is that only the soil skeleton is taken into account, while the reinforcing effect is considered as an equivalent additional stress acting on the soil skeleton in the direction of the reinforcement bedding. The existing constitutive model for soil can be directly used in this method without having to formulate new models. The procedures involved in the determination of the equivalent additional stress and other relevant parameters are also presented in the paper. Examples show that the new method can reasonably describe the stress-strain relationship of fiber-reinforced soil and soil structures reinforced with layers of reinforcement.