Download or read book Shear Band Propagation in Soils and Dynamics of Tsunamigenic Landslides written by Erich Saurer and published by vdf Hochschulverlag AG. This book was released on 2010 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Novel Applications of Distributed Fiber optic Sensing in Geotechnical Engineering written by Michael Iten and published by vdf Hochschulverlag AG. This book was released on 2012 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the variability of squeezing behaviour in tunnelling written by Florence Mezger and published by vdf Hochschulverlag AG. This book was released on 2020-07-01 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: On the variability of squeezing behaviour in tunnelling
Download or read book Experimental investigations for the modelling of anhydritic swelling claystones written by Tara Wanninger (-Huber) and published by vdf Hochschulverlag AG. This book was released on 2020-07-01 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental investigations for the modelling of anhydritic swelling claystones
Download or read book On the role of constitutive behaviour in the response of squeezing ground to tunnelling written by Weijie Dong and published by vdf Hochschulverlag AG. This book was released on 2017-08-14 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: Squeezing conditions in tunnelling are characterized by the occurrence of large deformations of the opening or high rock pressure that may overstress the lining. Squeezing is associated with poor quality rock. Tunnelling in squeezing ground involves great uncertainties. It is therefore very important to gain a better understanding of the underlying mechanisms. Triaxial testing is the main source of information in order to understand the mechanical features of squeezing ground. Despite the complexity of the squeezing mechanism and the behaviour observed under relatively simple loading conditions, most of previous research work and engineering design practice considers the ground as a linearly elastic, perfectly plastic material obeying the Mohr-Coulomb yield criterion. While the MC model is capable of predicting the final strength and post-failure volumetric behaviour of the squeezing rock, it cannot map some potentially important pre-failure features or the occasionally observed contractant plastic deformation. In addition, the MC model usually leads to an overestimation of the strength under undrained conditions, which is unsafe for tunnel design. The present thesis mainly addresses the influence of constitutive modelling on predictions about the response of squeezing ground to tunnelling in order to provide some general guidelines for basic engineering analysis. This objective is achieved by investigating the behaviour of squeezing rocks theoretically and experimentally, using samples from several tunnel projects, including the Gotthard base tunnel and the planned Gibraltar strait tunnel.
Download or read book Spatial Effects in Tunnelling Through Squeezing Ground written by Linard Cantieni and published by vdf Hochschulverlag AG. This book was released on 2011 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inverse Analysis in Road Geotechnics written by Carlo Rabaiotti and published by vdf Hochschulverlag AG. This book was released on 2011 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research work had the aim of developing a procedure for back-calculating accurate and precise parameter values, describing the mechanical behaviour of the materials built in an existing road structure. After reviewing the existing testing techniques, a new device was designed and assembled at the IGT, Institute for Geotechnical Engineering (ETH Zürich) for measuring the three dimensional deflection bowl under a standard axle load (SAL). Particular attention was paid for obtaining precise and accurate significant measurements for inverse analysis. Three field tests on different locations and road structures were carried out: a flexible pavement type built in a concrete pit (indoor facility) at the EPFL (Ecole Polytechnique Federale de Lausanne), a semirigid type in Hinwil (Switzerland) and a flexible type in Bellinzona (Hinwil). The tests results show that the measured road displacements under a SAL, for relatively low temperatures, are generally reversible and time independent. Laboratory tests (uniaxial compression) were carried out on cores obtained from field samples.The strain measurements of the loaded samples were carried out with strain gages, and validated against devices with different technology (LVDT). The analysis of the test results showed that the materials have different bulk and deviatoric stress-strain behaviour. A new thermodynamical framework for non linear viscoelasticity (hyperviscoelasticity) was developed. Experimentally validated hyperviscoelastic and hyperelastic constitutive laws were adopted respectively for describing the mechanical behaviour of asphalt and cement stabilized mixtures. The inverse analysis of the field tests results was carried out with two different optimization algorithms (Levenberg Marquardt and Mesh Adaptative Direct Search), the FE program ABAQUS, and the developed user defined models. The results demonstrate the accuracy and precision of the parameter values obtained with the proposed inverse analysis procedure, demonstrating a potential for application of the developed technique for non destructing testing of real road structures.
Download or read book Static effects and aspects of feasibility and design of drainages in tunnelling written by Sara Zingg and published by vdf Hochschulverlag AG. This book was released on 2017-02-21 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis investigates the effectiveness of drainage measures with respect to two particularly important problems associated with tunnelling through water-bearing, weak ground: the stability of the tunnel face and the stability and deformation of grouting bodies. Water is an adverse factor with respect to the stability and deformation of underground structures due to the pore water pressure and the seepage forces associated with seepage flow towards the tunnel. Drainage boreholes reduce the pore water pressure and the seepage forces in the vicinity of the cavity. Furthermore, loss of pore water pressure increases the effective stresses and thus the shearing resistance of the ground („consolidation“), which is favourable in terms the deformation occurring during and after tunnelling. The goal of the PhD thesis is to elaborate a more detailed understanding of the interrelationships between drainage measures and the stability of the tunnel face and grouting bodies. The main objectives of the investigations relating to the tunnel face are: 1. analysis of face stability through limit equilibrium computations taking account of the numerically determined seepage flow conditions prevailing in the ground after the implementation of drainage measures; 2. systematic investigation of tunnel face stability considering several different drainage layouts and working out designnomograms; 3. consideration of a series of aspects limiting pore pressure relief and thus the effectiveness of drainage measures and their impact on face stability. The main objectives of the investigations with regard to grouting bodies are: 1. a study of the stabilizing effect of the virtual case of ideal drainage on tunnel support and plastification in grouted fault zones in plane strain conditions; 2. a comparison with the stabilizing effect of real drainage layouts, i.e. when considering pore pressure relief due to specific drainage borehole arrangements; 3. application of the drainage measure both before and after the injection works. In summary, the contribution of this PhD thesis is the detailed investigation of the static effects of drainage measures during tunnelling in water-bearing ground with respect to the stability of the tunnel face and the grouting body as well as the supply of design aids capable of providing a quick assessment of face stability when considering a number of advance drainage schemes.
Download or read book River dyke failure modeling under transient water conditions written by Wilmer Ferney Morales Peñuela and published by vdf Hochschulverlag AG. This book was released on 2015-11-26 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knowledge of the performance of river dykes during flooding is necessary when designing governmental assistance plans aimed to reduce both casualties and material damage. This is especially relevant when floods have increased in their frequency during the last decades, together with the resulting material damage and life costs. Most of previous attempts for analyzing dyke breaching during flooding have neglected to consider the soil mechanics component and the influence of infiltration and saturation changes on the failure mechanisms developed in the river dyke. This research project aimed to fill that gap in knowledge by analyzing, in a comprehensive manner, the effect of transient water conditions, represented by successive flood cycles, on the seepage conditions and subsequent breaching of dykes. Therefore, three key sub-projects were carried out: • the analysis of the results from an overflow field test, • the physical modeling of small-scaled models under an enhanced gravity field, • the numerical modeling of the flow response and the resulting stability of both the air- and water-side slopes. The results from the numerical simulations matched accurately with the results obtained with the centrifuge modeling, including the prediction of local instabilities during the flood cycles for those dykes that did not include a toe filter.
Download or read book Centrifuge modelling of ground improvement for double porosity clay written by Emma Jane Pooley and published by vdf Hochschulverlag AG. This book was released on 2015-11-10 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Prediction and Simulation Methods for Geohazard Mitigation written by Fusao Oka and published by CRC Press. This book was released on 2009-05-07 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last decades have shown a remarkable increase in the number of heavy rains, typhoons and earthquakes. These natural phenomena are the main causes for geohazards. As a result the mitigation of geohazards has become a major research topic in geotechnical engineering, and in recent years simulation-based predictions and monitoring tools have been
Download or read book Landslides in Sensitive Clays written by Vikas Thakur and published by Springer. This book was released on 2017-05-23 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the most recent scientific research on the geological, geotechnical and geophysical aspects of slope failure in sensitive clays. Gathering contributions by international experts, it focuses on understanding the complete and practical spectrum of challenges presented by landslides in such complex materials. Based on sound and validated research results, the book also presents several recommendations that could be implemented in the guidelines or code-of-practice. These recommendations cover topics including the characterization and behavior of sensitive clays; the pre-failure, failure and post-failure stages of sensitive clays; mapping and identification methods; climate change; hazard assessment; and risk management. Sensitive clays are known for their potential for causing large landslides, which pose a serious risk to human lives, infrastructure, and surrounding ecosystems within their reach. This has been demonstrated by the recent catastrophic landslides in e.g. Sørum (2016), Skjeggestad (2015), Statland (2014), Byneset (2012), St-Jude (2010), Lyngen (2010) and Kattmarka (2009). The 2015 collapse of the Skjeggestad Bridge in Norway – which was due to a landslide in sensitive clay – alone costs millions of dollars in repairs. Recently, efforts are being made to increase society’s ability to cope with such landslide hazards. Geoscientists are now expected to provide input to the agencies responsible for landslide-risk preparedness. In other words, geoscientists’ role is not only to act as technologists to establish new theories, but also to go the extra mile to implement them in practice, so as to find meaningful solutions to geotechnical problems.
Download or read book Waves and Vibrations in Soils written by Jean-François Semblat and published by Iuss Press. This book was released on 2009 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 2005 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Meso Scale Shear Physics in Earthquake and Landslide Mechanics written by Yossef H. Hatzor and published by CRC Press. This book was released on 2009-09-28 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The identification of meso-scale phenomena – occurring between microscopic and continuum length scales – has been one of the most exciting developments in rock mechanics in the last decade. Meso-scale phenomena are considered as the bridge between the two length scales in understanding shear between material interfaces as well as particulate systems and in studying material response. Examples are the initiation of seismic slip along fault planes at great depths at rates nearing shock conditions, and the initiation and rapid runout of landslides near the earth’s surface. Additionally, the basic physics of thermo-poro-mechanical coupling can be elucidated through a meso-scale mechanics approach as a means of understanding the loss of shearing resistance when water and heat are trapped inside almost impervious clay layers under great pressure. This book presents a collection of 21 current, peer-reviewed articles on shear physics at the meso-scale in earthquake and landslide mechanics, authored by leading international experts in the field. Contributions are grouped in 5 chapters, discussing (1) the dynamics of frictional slip, (2) fault gauge mechanics, (3) experimental fault zone mechanics, (4) granular shear and liquefaction, and (5) landslides’ dynamics. This research area has broad applications to the fields of earth sciences and geoengineering, with immediate bearing on our understanding of both earthquake and landslide mechanics, two geological processes that pose great risk to man kind worldwide.
Download or read book Landslides and Engineered Slopes Experience Theory and Practice written by Stefano Aversa and published by CRC Press. This book was released on 2018-04-17 with total page 2224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Landslides and Engineered Slopes. Experience, Theory and Practice contains the invited lectures and all papers presented at the 12th International Symposium on Landslides, (Naples, Italy, 12-19 June 2016). The book aims to emphasize the relationship between landslides and other natural hazards. Hence, three of the main sessions focus on Volcanic-induced landslides, Earthquake-induced landslides and Weather-induced landslides respectively, while the fourth main session deals with Human-induced landslides. Some papers presented in a special session devoted to "Subareal and submarine landslide processes and hazard” and in a “Young Session” complete the books. Landslides and Engineered Slopes. Experience, Theory and Practice underlines the importance of the classic approach of modern science, which moves from experience to theory, as the basic instrument to study landslides. Experience is the key to understand the natural phenomena focusing on all the factors that play a major role. Theory is the instrument to manage the data provided by experience following a mathematical approach; this allows not only to clarify the nature and the deep causes of phenomena but mostly, to predict future and, if required, manage similar events. Practical benefits from the results of theory to protect people and man-made works. Landslides and Engineered Slopes. Experience, Theory and Practice is useful to scientists and practitioners working in the areas of rock and soil mechanics, geotechnical engineering, engineering geology and geology.
Download or read book Submarine Mass Movements and Their Consequences written by Sebastian Krastel and published by Springer Science & Business Media. This book was released on 2013-09-02 with total page 677 pages. Available in PDF, EPUB and Kindle. Book excerpt: Submarine mass movements are a hidden geohazard with large destructive potential for submarine installations and coastal areas. This hazard and associated risk is growing in proportion with increasing population of coastal urban agglomerations, industrial infrastructure, and coastal tourism. Also, the intensified use of the seafloor for natural resource production, and deep sea cables constitutes an increasing risk. Submarine slides may alter the coastline and bear a high tsunamogenic potential. There is a potential link of submarine mass wasting with climate change, as submarine landslides can uncover and release large amounts greenhouse gases, mainly methane, that are now stored in marine sediments. The factors that govern the stability of submarine slopes against failure, the processes that lead to slope collapses and the collapse processes by themselves need to be better understood in order to foresee and prepare society for potentially hazardous events. This book volume consists of a collection of cutting edge scientific research by international experts in the field, covering geological, geophysical, engineering and environmental aspects of submarine slope failures. The focus is on understanding the full spectrum of challenges presented by this major coastal and offshore geohazard.
