On the Face Stability of Shallow Tunnels in Sand

On the Face Stability of Shallow Tunnels in Sand PDF Author: Ansgar Kirsch
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832521496
Category : Technology & Engineering
Languages : en
Pages : 213

Get Book Here

Book Description
Various models have been proposed for the prediction of the necessary support pressure at the face of a shallow tunnel. To assess their quality, the collapse of a tunnel face was modelled with small scale model tests at single gravity. The evolution of the failure mechanism and the development of the support force at the face in dry sand were investigated. The observed displacement patterns show a negligible influence of overburden on the extent and evolution of the failure zone. The latter is significantly influenced, though, by the initial density of the sand: in dense sand a chimney-wedge-type collapse mechanism developed, which propagated towards the soil surface. Initially loose sand did not show any development of a discrete collapse mechanism. The necessary support force was neither influenced by the overburden nor the initial density. A comparison with quantitative predictions by several theoretical models showed that the measured necessary support pressure is overestimated by most of the models. Only those by Vermeer/Ruse and Leca/Dormieux were able to predict the necessary support pressure on a 95 % confidence level. A three-dimensional finite element investigation of face stability served to assess the ability of two constitutive models, an elastoplastic Mohr-Coulomb and a hypoplastic model, to predict the necessary support pressure and the displacements at the tunnel face. The simulation of the small scale experiments revealed that the observed necessary support pressure and incremental displacements were predicted sufficiently well with both constitutive models.

On the Face Stability of Shallow Tunnels in Sand

On the Face Stability of Shallow Tunnels in Sand PDF Author: Ansgar Kirsch
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832521496
Category : Technology & Engineering
Languages : en
Pages : 213

Get Book Here

Book Description
Various models have been proposed for the prediction of the necessary support pressure at the face of a shallow tunnel. To assess their quality, the collapse of a tunnel face was modelled with small scale model tests at single gravity. The evolution of the failure mechanism and the development of the support force at the face in dry sand were investigated. The observed displacement patterns show a negligible influence of overburden on the extent and evolution of the failure zone. The latter is significantly influenced, though, by the initial density of the sand: in dense sand a chimney-wedge-type collapse mechanism developed, which propagated towards the soil surface. Initially loose sand did not show any development of a discrete collapse mechanism. The necessary support force was neither influenced by the overburden nor the initial density. A comparison with quantitative predictions by several theoretical models showed that the measured necessary support pressure is overestimated by most of the models. Only those by Vermeer/Ruse and Leca/Dormieux were able to predict the necessary support pressure on a 95 % confidence level. A three-dimensional finite element investigation of face stability served to assess the ability of two constitutive models, an elastoplastic Mohr-Coulomb and a hypoplastic model, to predict the necessary support pressure and the displacements at the tunnel face. The simulation of the small scale experiments revealed that the observed necessary support pressure and incremental displacements were predicted sufficiently well with both constitutive models.

Limit Analysis and Soil Plasticity

Limit Analysis and Soil Plasticity PDF Author: Wai-Fah Chen
Publisher: Elsevier
ISBN: 0444601066
Category : Science
Languages : en
Pages : 653

Get Book Here

Book Description
Developments in Geotechnical Engineering, Volume 7: Limit Analysis and Soil Plasticity covers the theory and applications of limit analysis as applied to soil mechanics. Organized into 12 chapters, the book presents an introduction to the modern development of theory of soil plasticity and includes rock-like material. The first four chapters of the book describe the technique of limit analysis, beginning with the historical review of the subject and the assumptions on which it is based, and then covering various aspects of available techniques of limit analysis. The subsequent chapters deal with the applications of limit analysis to what may be termed "classical soil mechanics problems that include bearing capacity of footings, lateral earth pressure problems, and stability of slopes. In many cases, comparisons of limit analysis solution and conventional limit equilibrium and slip-like solutions are also presented. Other chapters deal with the advances in bearing-capacity problem of concrete blocks or rock and present theoretical and experimental results of various concrete bearing problems. The concluding chapter examines elastic-plastic soil and elastic-plastic-fracture models for concrete materials. This book is an ideal resource text to geotechnical engineers and soil mechanics researchers.

Mechanized Tunnelling in Urban Areas

Mechanized Tunnelling in Urban Areas PDF Author: Vittorio Guglielmetti
Publisher: CRC Press
ISBN: 1134110561
Category : Technology & Engineering
Languages : en
Pages : 507

Get Book Here

Book Description
Internationally, the mechanized excavation of tunnels has intensified in the last two decades, as the number of tunnels being constructed for subways and railway underpasses increases. The subject of mechanized tunnelling in urban areas has not previously received the attention that it deserves, despite there being specific hazards associated with the construction of tunnels in metropolitan areas, including poor ground conditions, water tables higher than the level of tunnels, and subsidence leading to damage to the existing structures on the surface. The application of technologies for achieving the stability of the tunnel and for minimizing surface settlement is described in this book. Accurate characterization of the ground; rigorous assessment and management of risk from design to maintenance; the correct choice of a tunnel boring machine and a plan for the advancement of the tunnel; specific excavation procedures and real-time monitoring of excavation parameters are all discussed in this thorough work.

Geotechnical Aspects of Underground Construction in Soft Ground

Geotechnical Aspects of Underground Construction in Soft Ground PDF Author: Klaas Jan Bakker
Publisher: CRC Press
ISBN: 9780415889131
Category : Technology & Engineering
Languages : en
Pages : 984

Get Book Here

Book Description
A valuable source of reference on the current practices of analysis, design and construction of tunnels and underground structures in soft ground. This collection of reviewed papers covers a wide range of tunnelling practice, from deep excavations in Singapore to the construction of a new metro line in Barcelona. The international scope of the contributors makes this a truly comprehensive collection of work on the geotechnical aspects of soft ground excavation.

Design and Construction of Tunnels

Design and Construction of Tunnels PDF Author: Pietro Lunardi
Publisher: Springer Science & Business Media
ISBN: 3540738754
Category : Science
Languages : en
Pages : 580

Get Book Here

Book Description
This work illustrates how the Analysis of Controlled Deformation in Rocks and Soils (ADECO-RS) is used in the design and the construction of tunnels. This is a very new and effective way of tunnel construction. The ADECO-RS approach makes a clear distinction between the design and the construction stages and allows reliable forecasts of construction times and costs to be made. It uses the advance core (the core of ground ahead of the face) as a structural tool for the long and short term stabilisation of tunnels, after its rigidity has first been regulated using conservation techniques.

Introduction to Tunnel Construction

Introduction to Tunnel Construction PDF Author: David Chapman
Publisher: CRC Press
ISBN: 1498766455
Category : Technology & Engineering
Languages : en
Pages : 557

Get Book Here

Book Description
Tunnelling provides a robust solution to a variety of engineering challenges. It is a complex process, which requires a firm understanding of the ground conditions as well as the importance of ground-structure interaction. This book covers the full range of areas related to tunnel construction required to embark upon a career in tunnelling. It also includes a number of case studies related to real tunnel projects, to demonstrate how the theory applies in practice. New features of this second edition include: the introduction of a case study related to Crossrail’s project in London, focussing on the Whitechapel and Liverpool Street station tunnels and including considerations of building tunnels in a congested urban area; and further information on recent developments in tunnel boring machines, including further examples of all the different types of machine as well as multi-mode machines. The coverage includes: Both hard-rock and soft-ground conditions Site investigation, parameter selection, and design considerations Methods of improving the stability of the ground and lining techniques Descriptions of the various main tunnelling techniques Health and safety considerations Monitoring of tunnels during construction Description of the latest tunnel boring machines Case studies with real examples, including Crossrail’s project in London Clear, concise, and heavily illustrated, this is a vital text for final-year undergraduate and MSc students and an invaluable starting point for young professionals and novices in tunnelling.

Soft Rock Mechanics and Engineering

Soft Rock Mechanics and Engineering PDF Author: Milton Kanji
Publisher: Springer Nature
ISBN: 3030294773
Category : Science
Languages : en
Pages : 753

Get Book Here

Book Description
This book offers a practical reference guide to soft rock mechanics for engineers and scientists. Written by recognized experts, it will benefit professionals, contractors, academics, researchers and students working on rock engineering projects in the fields of civil engineering, mining and construction engineering. Soft Rock Mechanics and Engineering covers a specific subject of great relevance in Rock Mechanics – and one that is directly connected to the design of geotechnical structures under difficult ground conditions. The book addresses practical issues related to the geomechanical properties of these types of rock masses and their characterization, while also discussing advances regarding in situ investigation, safety, and monitoring of geotechnical structures in soft rocks. Lastly, it presents important case histories involving tunnelling, dam foundations, coal and open pit mines and landslides.

Mechanised Shield Tunnelling

Mechanised Shield Tunnelling PDF Author: Bernhard Maidl
Publisher: John Wiley & Sons
ISBN: 3433601496
Category : Technology & Engineering
Languages : en
Pages : 489

Get Book Here

Book Description
Mechanised shield tunnelling has developed considerably since the publication of the first edition of this book. Challenging tunnel projects under difficult conditions demand innovative solutions, which has led to constant further development and innovation in process technology, constructions operations and the machines and materials used. The book collects the latest state of technology in mechanised shield tunnelling. It describes the basics of mechanised tunnelling technology and the various types of machines and gives calculation methods and constructural advice. Further chapters cover excavation tools, muck handling, tunnel support, surveying and steering as well as workplace safety. There is also detailled information about contractual aspects and process controlling.

Tunnel Engineering

Tunnel Engineering PDF Author: Michael Sakellariou
Publisher: BoD – Books on Demand
ISBN: 1789854652
Category : Technology & Engineering
Languages : en
Pages : 296

Get Book Here

Book Description
This volume presents a selection of chapters covering a wide range of tunneling engineering topics. The scope was to present reviews of established methods and new approaches in construction practice and in digital technology tools like building information modeling. The book is divided in four sections dealing with geological aspects of tunneling, analysis and design, new challenges in tunnel construction, and tunneling in the digital era. Topics from site investigation and rock mass failure mechanisms, analysis and design approaches, and innovations in tunnel construction through digital tools are covered in 10 chapters. The references provided will be useful for further reading.

Analytical Methods in Petroleum Upstream Applications

Analytical Methods in Petroleum Upstream Applications PDF Author: Cesar Ovalles
Publisher: CRC Press
ISBN: 1138001481
Category : Science
Languages : en
Pages : 2054

Get Book Here

Book Description
Effective measurement of the composition and properties of petroleum is essential for its exploration, production, and refining; however, new technologies and methodologies are not adequately documented in much of the current literature. Analytical Methods in Petroleum Upstream Applications explores advances in the analytical methods and instrumentation that allow more accurate determination of the components, classes of compounds, properties, and features of petroleum and its fractions. Recognized experts explore a host of topics, including: A petroleum molecular composition continuity model as a context for other analytical measurements A modern modular sampling system for use in the lab or the process area to collect and control samples for subsequent analysis The importance of oil-in-water measurements and monitoring The chemical and physical properties of heavy oils, their fractions, and products from their upgrading Analytical measurements using gas chromatography and nuclear magnetic resonance (NMR) applications Asphaltene and heavy ends analysis Chemometrics and modeling approaches for understanding petroleum composition and properties to improve upstream, midstream, and downstream operations Due to the renaissance of gas and oil production in North America, interest has grown in analytical methods for a wide range of applications. The understanding provided in this text is designed to help chemists, geologists, and chemical and petroleum engineers make more accurate estimates of the crude value to specific refinery configurations, providing insight into optimum development and extraction schemes.