Geotechnics of Soft Soils: Focus on Ground Improvement


Book Description

Natural soft soils are very complex materials. As construction activities increasingly take place in poor ground conditions, ground improvement is often required. However, design practices for ground improvement were for long at best crude and conservative, and at worst unsafe. Although new construction and field observation techniques have been de




Ground Improvement


Book Description

- The first book of its kind, providing over thirty real-life case studies of ground improvement projects selected by the worlds top experts in ground improvement from around the globe. - Volume 3 of the highly regarded Elsevier Geo-engineering book series coordinated by the Series Editor: Professor John A Hudson FREng. - An extremely reader friendly chapter format. - Discusses wider economical and environmental issues facing scientists in the ground improvement.Ground improvement has been both a science and art, with significant developments observed through ancient history. From the use of straw as blended infill with soils for additional strength during the ancient Roman civilizations, and the use of elephants for compaction of earth dams during the early Asian civilizations, the concepts of reinforced earth with geosynthetics, use of electrokinetics and thermal modifications of soils have come a long way. The use of large and stiff stone columns and subsequent sand drains in the past has now been replaced by quicker to install and more effective prefabricated vertical drains, which have also eliminated the need for more expensive soil improvement methods.The early selection and application of the most appropriate ground improvement techniques can improve considerably not only the design and performance of foundations and earth structures, including embankments, cut slopes, roads, railways and tailings dams, but also result in their cost-effectiveness. Ground improvement works have become increasingly challenging when more and more problematic soils and marginal land have to be utilized for infrastructure development.This edited compilation contains a collection of Chapters from invited experts in various areas of ground improvement, who have illustrated the basic concepts and the applications of different ground improvement techniques using real projects that they have been involved in. The case histories from many countries ranging from Asia, America, Australia and Europe are addressed.




Soft Clay Engineering and Ground Improvement


Book Description

Soft Clay Engineering and Ground Improvement covers the design and implementation of ground improvement techniques as applicable to soft clays. This particular subject poses major geotechnical challenges in civil engineering. Not only civil engineers, but planners, architects, consultants and contractors are now aware what soft soils are and the risks associated with development of such areas. The book is designed as a reference and useful tool for those in the industry, both to consultants and contractors. It also benefits researchers and academics working on ground improvement of soft soils, and serves as an excellent overview for postgraduates. University lecturers are beginning to incorporate more ground improvement topics into their curricula, and this text would be ideal for short courses for practicing engineers. It includes several examples to assist a newcomer to carry out preliminary designs. The three authors, each with dozens of years of experience, have witnessed and participated in the rapid evolvement of ground improvement in soft soils. In addition, top-tier professionals who deal with soft clays and ground improvement on a daily basis have contributed, providing their expertise in dealing with real-world problems and practical solutions.




Ground Improvement by Deep Vibratory Methods


Book Description

Vibro compaction and vibro stone columns are the two dynamic methods of soil improvement most commonly used worldwide. These methods have been developed over almost eighty years and are now of unrivalled importance as modern foundation measures. Vibro compaction works on granular soils by densification, and vibro stone columns are used to displace and reinforce fine-grained and cohesive soils by introducing inert material. This second edition includes also a chapter on vibro concrete columns constructed with almost identical depth vibrators. These small diameter concrete piles are increasingly used as ground improvement methods for moderately loaded large spread foundations, although the original soil characteristics are only marginally improved. This practical guide for professional geotechnical engineers and graduate students systematically covers the theoretical basis and design principles behind the methods, the equipment used during their execution, and state of the art procedures for quality assurance and data acquisition. All the chapters are updated in line with recent developments and improvements in the methods and equipment. Fresh case studies from around the world illustrate the wide range of possible applications. The book concludes with variations to methods, evaluates the economic and environmental benefits of the methods, and gives contractual guidance. The Open Access version of this book, available at http://www.taylorfrancis.com, has been made available under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license




Ground Improvement Techniques


Book Description

This book provides a review of problems during design and construction on problematic soils. Design methods, site investigation, construction and analysis of the various improvement methods available are explained and discussed. Various regions may have different soils with geotechnical problems that differ from those faced in other regions. For example, in Southeast Asia, the common geotechnical problems are those associated with construction on soft clays and organic soils, while in the arid region of the Middle East, problems are generally associated with the desert soils. In the US, the problems are associated with organic soils, expansive and collapsing soils, and shale. Laterite and lateritic soils are especially problematic in Mexico. Similarly, in Europe, for example, the geotechnical problems are associated with loess (France), and organic soil (Germany). A detailed description of various methods of ground improvement has been provided in 11 chapters. Each chapter deals not only with a description of the method but also focuses on region-specific ground problems and suitable ground improvement techniques. Case studies have also been included. One general chapter is dedicated to site investigation, instrumentation, assessment and control. This book will be of value to students and professionals in the fields of civil and geotechnical engineering, as well as to soil scientists and engineering geologists.




Ground Improvement, Third Edition


Book Description

When finding another location, redesigning a structure, or removing troublesome ground at a project site are not practical options, prevailing ground conditions must be addressed. Improving the ground—modifying its existing physical properties to enable effective, economic, and safe construction—to achieve appropriate engineering performance is an increasingly successful approach. This third edition of Ground Improvement provides a comprehensive overview of the major ground improvement techniques in use worldwide today. Written by recognized experts who bring a wealth of knowledge and experience to bear on their contributions, the chapters are fully updated with recent developments including advancements in equipment and methods since the last edition. The text provides an overview of the processes and the key geotechnical and design considerations as well as equipment needed for successful execution. The methods described are well illustrated with relevant case histories and include the following approaches: Densification using deep vibro techniques or dynamic compaction Consolidation employing deep fabricated drains and associated methods Injection techniques, such as permeation and jet grouting, soil fracture grouting, and compaction grouting New in-situ soil mixing processes, including trench-mixing TRD and panel-mixing CSM approaches The introductory chapter touches on the historical development, health and safety, greenhouse gas emissions, and two less common techniques: blasting and the only reversible process, ground freezing. This practical and established guide provides readers with a solid basis for understanding and further study of the most widely used processes for ground improvement. It is particularly relevant for civil and geotechnical engineers as well as contractors involved in piling and ground engineering of any kind. It would also be useful for advanced graduate and postgraduate civil engineering and geotechnical students.




From Fundamentals to Applications in Geotechnics


Book Description

The work of geotechnical engineers contributes to the creation of safe, economic and pleasant spaces to live, work and relax all over the world. Advances are constantly being made, and the expertise of the profession becomes ever more important with the increased pressure on space and resources. This book presents the proceedings of the 15th Pan-American Conference on Soil Mechanics and Geotechnical Engineering (XV PCSMGE), held in Buenos Aires, Argentina, in November 2015. This conference, held every four years, is an important opportunity for international experts, researchers, academics, professionals and geo-engineering companies to meet and exchange ideas and research findings in the areas of soil mechanics, rock mechanics, and their applications in civil, mining and environmental engineering. The articles are divided into nine sections: transportation geotechnics; in-situ testing; geo-engineering for energy and sustainability; numerical modeling in geotechnics; foundations and ground improvement; unsaturated soil behavior; embankments, dams and tailings; excavations and tunnels; and geo-risks, and cover a wide spectrum of issues from fundamentals to applications in geotechnics. This book will undoubtedly represent an essential reference for academics, researchers and practitioners in the field of soil mechanics and geotechnical engineering. In this proceedings, approximately 65% of the contributions are in English, and 35% of the contributions are in Spanish or Portuguese.




Ground Improvement By Deep Vibratory Methods


Book Description

Vibro-compaction and vibro-stone columns are the two dynamic methods of soil improvement most commonly used worldwide. These methods have been developed over seventy years and are now in a position of unrivalled importance amongst modern foundation measures. The first works on granular soil by densification, and the second is used to displace and reinforce fine grained and cohesive soils by introducing inert material. This practical guide for professional geotechnical engineers outlines the development of vibratory deep compaction, describes the equipment used, sets out the methods and techniques and provides state of the art design principles and quality control procedures. It also identifies the practical limitations of the methods. Case studies from South East Asia and the Middle East are used to illustrate the methods and to demonstrate how they apply in real world conditions. The book concludes with some variations of the basic methods, evaluates the economic and environmental benefits of the methods and gives contractual guidance.




Centrifuge modelling of ground improvement for double porosity clay


Book Description

Double porosity soil is characterised by a soil continuum containing two distinct porosities. Typically, this consists of macro-grains (lumps) of soil that have an internal porosity defined as the intragranular porosity. The spaces between lumps are identified as intergranular voids that give rise to the intergranular porosity. Human activities such as land reclamation or mining can give rise to large areas of land with subsoil that exhibits double porosity. The need to build in, or on, these areas is increasing, due to demand for land for industrial usage, infrastructure, and residence. However, the engineering properties of such soils are challenging, and often difficult to predict due to their inhomogeneity and a lack of information about the initial or current parameters. Double porosity mining waste landfills in Northern Bohemia in the Czech Republic were studied in this project. There, decades of open-cast mining of brown coal have left vast areas of land affected by the waste overburden that has been removed and dumped in old mining pits. Redevelopment of areas affected by mining sometimes requires construction on old overburden waste spoil heaps, which consist primarily of lumps of overconsolidated clay and are therefore characterised by a double porosity soil structure. The loading response on these clayfills entails large absolute and relative deformations, which means that ground improvement is normally needed before construction begins, to ensure that both stability and service limit state requirements are met. The primary aim of this research was a comparison, through physical modelling, of ground improvement techniques on double porosity clay landfills. A secondary objective was to contribute to the understanding of the material behaviour governing response to loading and other processes on double porosity soil.




Numerical Methods in Geotechnical Engineering IX


Book Description

Numerical Methods in Geotechnical Engineering IX contains 204 technical and scientific papers presented at the 9th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE2018, Porto, Portugal, 25—27 June 2018). The papers cover a wide range of topics in the field of computational geotechnics, providing an overview of recent developments on scientific achievements, innovations and engineering applications related to or employing numerical methods. They deal with subjects from emerging research to engineering practice, and are grouped under the following themes: Constitutive modelling and numerical implementation Finite element, discrete element and other numerical methods. Coupling of diverse methods Reliability and probability analysis Large deformation – large strain analysis Artificial intelligence and neural networks Ground flow, thermal and coupled analysis Earthquake engineering, soil dynamics and soil-structure interactions Rock mechanics Application of numerical methods in the context of the Eurocodes Shallow and deep foundations Slopes and cuts Supported excavations and retaining walls Embankments and dams Tunnels and caverns (and pipelines) Ground improvement and reinforcement Offshore geotechnical engineering Propagation of vibrations Following the objectives of previous eight thematic conferences, (1986 Stuttgart, Germany; 1990 Santander, Spain; 1994 Manchester, United Kingdom; 1998 Udine, Italy; 2002 Paris, France; 2006 Graz, Austria; 2010 Trondheim, Norway; 2014 Delft, The Netherlands), Numerical Methods in Geotechnical Engineering IX updates the state-of-the-art regarding the application of numerical methods in geotechnics, both in a scientific perspective and in what concerns its application for solving practical boundary value problems. The book will be much of interest to engineers, academics and professionals involved or interested in Geotechnical Engineering.