Download or read book A Finite Element Framework for Geotechnical Applications Based on Object oriented Programming written by Peter Fritz and published by vdf Hochschulverlag AG. This book was released on 2002 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computer Methods and Advances in Geomechanics written by D. Contractor and published by CRC Press. This book was released on 2000-01-01 with total page 914 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering a wide range of topics involving both research developments and applications, resulting from the 10th International Conferecne on Computer Methods and Advances in Geomechanics (IACMAG) held in January 2001 in Tucson, Arizona, USA. The theme of the conference was Fundamentals through Applications. The up-to-date research results and applications in this 2-volume work (> 1900 pages) should serve as a valuable source of information for those engaged in research, analysis and design, practical application, and education in the fields of geomechanics and geotechnical engineering.
Download or read book Application of Numerical Methods to Geotechnical Problems written by Annamaria Cividini and published by Springer. This book was released on 2014-05-04 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NUMGE98 Conference brought together senior and young researchers, scientists and practicing engineers from European and overseas countries, to share their knowledge and experience on the various aspects of the analysis of Geotechnical Problems through Numerical Methods. The papers address a broad spectrum of geotechnical problems, including tunnels and underground openings, shallow and deep foundations, slope stability, seepage and consolidation, partially saturated soils, geothermal effects, constitutive modelling, etc.
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 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 Instabilities in alpine permafrost strength and stiffness in a warming regime written by Yuko Yamamoto and published by vdf Hochschulverlag AG. This book was released on 2014-08-20 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alpine permafrost exists at high altitude at lower latitudes, such as in the Swiss Alps. Accelerating climate change, including rising mean annual air temperature and extreme rainfall conditions in alpine regions induces permafrost degradation. The warming of permafrost causes accelerated creep of rock glaciers, due to increased unfrozen water content and higher deformability of the ice phase. Recently, the development of deepening depressions has been observed in several rock glaciers in Switzerland, and the changes in land surface characteristics and drainage systems may initiate slope instabilities in rock glaciers. The main aim of this thesis is to characterise the strength and stiffness of alpine frozen soil in rock glaciers. To this end, the geotechnical response, such as creep and failure of frozen soil was investigated through a triaxial stress path testing programme with novel measurement systems for detecting acoustic emissions and measuring volumetric change. In addition, the resistance to crack initiation and propagation was investigated through a beam bending test programme on rectangular artificially frozen soil specimens, using the acoustic emission measurement system. The evaluation of laboratory tests on artificially frozen soil specimens implied that the development of deep depressions in rock glaciers occurs through differential creep and thermal degradation, and that the rate of deformation has the potential to lead to instabilities in rock glaciers. A comparison of the simulation results with the experimental data demonstrated that the semi-coupled model was successful in simulating the most important aspects of the temperature-dependent stress-strain relationship for the frozen soil behaviour that was measured at the element scale. This thesis contributes to an understanding of the variations in geotechnical response of alpine permafrost, by investigating the behaviour of artificially frozen soil specimens experimentally and numerically with time and temperature under specific stress paths. However, further investigations are necessary to assess the long-term stability of rock glaciers affected by climate change.
Download or read book Failure mechanisms in unsaturated silty sand slopes triggered by rainfall written by Amin Askarinejad and published by vdf Hochschulverlag AG. This book was released on 2015-11-26 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Landslides triggered by rainfall cause significant damage to infrastructure annually and affect many lives in several parts of the world, including Switzerland. These landslides are initiated by a decrease in the effective stresses, and hence the shear strength of the soil, as a result of the increase in pore water pressure. The frequency of their occurrence is directly affected by the climatic and hydrological conditions in the region. Therefore, it is expected that the predicted rise in the number of extreme meteorological events, accompanied by the concentration of population and infrastructure in mountainous regions, will result in an increased number of casualties associated with landslides in the future. The main goal of this doctoral project was to study the effects of pore water pressure perturbations on the stability of unsaturated silty sand slopes and to investigate the mechanisms leading to the initiation and propagation of the shear deformations and eventually possible rapid mass movements. The behaviour of the test slope prior to the failure induced by the artificial rainfall event was investigated using analytical and numerical methods. The mechanical features of unsaturated soils and reinforcing effects of the vegetation were implemented in 2D and 3D limit equilibrium analysis. The possible depth of the failure surface was calculated based on these simplified models and was compared with the depth of the real failure surface in the landslide triggering experiment. The soil-bedrock interactions, in terms of the pattern of pore pressure distributions and their influence on stabilising or destabilising the slope, were studied and the results were compared to the field measurements.
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 On the Feasibility of TBM Drives in Squeezing Ground and the Risk of Shield Jamming written by Marco Ramoni and published by vdf Hochschulverlag AG. This book was released on 2010 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Squeezing ground represents a challenging operating environment as it may slow down or obstruct TBM operation. Due to the geometrical constraints of the equipment, relatively small convergences of 10-20 cm may lead to considerable difficulties in the machine area (sticking of the cutter head, jamming of the shield) or in the back-up area (e.g., jamming of the back-up equipment, inadmissible convergences of the bored profile, damage to the tunnel support). Depending on the number and the length of the critical stretches, squeezing conditions may even call into question the feasibility of a TBM drive. On account of this, and bearing in mind the steady increase in the number of tunnels excavated with TBMs through so-called "difficult ground conditions", the topic investigated in this PhD thesis is of great practical relevance.Based upon case histories reported in the literature, Part I sets out firstly to give an overview of the specific problems of TBM tunnelling under squeezing conditions. Part II presents a computational model which simulates accurately and efficiently the advancing TBM and the installed tunnel support in one single computational step applying the so-called "steady state method". Part III advances a number of theory-based decision aids, which will support rapid, initial assessments to be made of thrust force requirements. Part IV investigates the complex problem of the interaction between the advancing TBM, the consolidating ground and the lining. Emphasis is thereby placed on the effect of the gross advance rate and the effect of ground permeability on shield loading during regular TBM operation (the boring process including short standstills) and during a long standstill.
Download or read book The Stability of Tunnels in Grouted Fault Zones written by Georgios Anagnostou and published by vdf Hochschulverlag AG. This book was released on 2003 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Micromechanical Analyses of Sturzstroms rock Avalanches on Earth and Mars written by Bernd Imre and published by vdf Hochschulverlag AG. This book was released on 2012 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Unstable Alpine Permafrost written by Lukas Urs Arenson and published by vdf Hochschulverlag AG. This book was released on 2003 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Soil and Modelling of Geotechnical Problems written by C. N. V. Satyanarayana Reddy and published by Springer Nature. This book was released on 2022-01-17 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides information on the latest technological developments taking place in Geotechnical engineering, pertaining to Soil Dynamics and Modelling of Geotechnical Problems. The book is useful for the academicians and working professionals with coverage of both theoretical and practical aspects of Dynamics of Soil and Modelling studies on Geotechnical problems based on research findings and site specific inputs. The book serves as a useful reference resource for graduate and postgraduate students of civil engineering and contents of the book are helpful to the postgraduate students and research scholars in carrying out the research.
Download or read book Proceedings of the 4th International Conference on Performance Based Design in Earthquake Geotechnical Engineering Beijing 2022 written by Lanmin Wang and published by Springer Nature. This book was released on 2022-09-19 with total page 2417 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 4th International Conference on Performance-based Design in Earthquake Geotechnical Engineering (PBD-IV) is held in Beijing, China. The PBD-IV Conference is organized under the auspices of the International Society of Soil Mechanics and Geotechnical Engineering - Technical Committee TC203 on Earthquake Geotechnical Engineering and Associated Problems (ISSMGE-TC203). The PBD-I, PBD-II, and PBD-III events in Japan (2009), Italy (2012), and Canada (2017) respectively, were highly successful events for the international earthquake geotechnical engineering community. The PBD events have been excellent companions to the International Conference on Earthquake Geotechnical Engineering (ICEGE) series that TC203 has held in Japan (1995), Portugal (1999), USA (2004), Greece (2007), Chile (2011), New Zealand (2015), and Italy (2019). The goal of PBD-IV is to provide an open forum for delegates to interact with their international colleagues and advance performance-based design research and practices for earthquake geotechnical engineering.
