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81.
Lessons learnt from field tests in some potentially unstable slopes in Switzerland
Sarah Springman, Armin Askarinejad, Francesca Casini, Sven Friedel, Peter Kinzler, Philipp Teysseire, Andrea Thielen, 2012, izvirni znanstveni članek

Opis: Rain-induced slope instability is a significant natural hazard in Switzerland, Slovenia and elsewhere in Europe. This contribution was prepared especially for the 12th Šuklje Symposium, and recognises that landslides occur both in mountain regions as well as in lowland regions during and following extreme-rainfall conditions. The Institute (and Professorship) for Geotechnical Engineering at the Swiss Federal Institute of Technology (ETH Zürich) has been engaged over several years in projects concerned with the characterisation, monitoring and modelling behaviour of slopes in mainly granular porous media across the full range of altitudes in Switzerland. A link is made to the doyen of the Šuklje day and then three case histories are presented and discussed to demonstrate the principal reactions to seasonal rainfall. A small slip was released in two of these cases and the “triggering” factors have been investigated and are discussed in this contribution. It transpires that the mode of inslope drainage influences the way in which the ground saturates and hence the volume of the potentially unstable ground. Simple stability analyses using limit equilibrium and soil parameters that have been amended to account for unsaturated soil behaviour were found to function well for slopes in largely granular media.
Ključne besede: rain-induced landslides, slope stability, case histories, monitoring, characterisation, modelling
Objavljeno: 13.06.2018; Ogledov: 21; Prenosov: 3
.pdf Celotno besedilo (1,79 MB)

82.
Editorial
Ludvik Trauner, 2012, predgovor, spremna beseda

Ključne besede: editorials, scientific journals, geomechanics, geotechnical engineering
Objavljeno: 13.06.2018; Ogledov: 14; Prenosov: 4
.pdf Celotno besedilo (36,27 KB)
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83.
Influence of mould suction on the volume - change behaviour of compacted soils during inundation
Matej Maček, Bojan Majes, Ana Petkovšek, 2011, izvirni znanstveni članek

Opis: After construction, compacted clayey soils in different earth structures equilibrate their water content and suction with the local environment. In wet climatic conditions the compaction on the dry side of the Proctor curve, which enables a high layer stiffness during construction, may result in permanent deformation and softening during the lifetime of the structure. This paper presents the results of the tests, performed on a relatively large number of compacted test specimens, where the conventional index parameters, used to identify compacted soils, were supplemented with a suction–water-content curve and measurements of “mould” suction. Correlations were established between the optimum water content and the suction–water-content curve for representative samples, and the influence of the mould suction on the vertical deformation of the compacted samples during inundation in oedometers was studied.
Ključne besede: oedometer tests, suction, swelling, collapse
Objavljeno: 13.06.2018; Ogledov: 19; Prenosov: 6
.pdf Celotno besedilo (391,47 KB)

84.
The stability of the excavation face of shallow civil and mining tunnels
Pierpaolo Oreste, 2011, izvirni znanstveni članek

Opis: The stability of the excavation face of shallow tunnels excavated in difficult ground conditions is currently a relevant problem in the sector for tunnelling and mining. Even though face-reinforcement interventions with fibreglass dowels have proved to be efficient, there is still no reliable analysis and dimensioning method available. A new calculation procedure is illustrated in this paper for the analysis of the face static condition in shallow tunnels, also when reinforcement interventions with fibreglass dowels are used. The procedure is based on the limit-equilibrium method applied to the ground core ahead of the face. The main result of the calculation is that the safety factor of the excavation face is also obtained in the presence of reinforcements and from this it is then possible to proceed with the dimensioning of the intervention. The procedure has been applied to two real cases and satisfactory results have been obtained.
Ključne besede: fibreglass dowels, face reinforcement, surface tunnel, limit equilibrium method, factor of safety
Objavljeno: 13.06.2018; Ogledov: 14; Prenosov: 5
.pdf Celotno besedilo (213,90 KB)

85.
Landslide assessment of the Strača basin (Croatia) using machine learning algorithms
Miloš Marjanović, Miloš Kovačević, Branislav Bajat, Snježana Mihalić Arbanas, Biljana Abolmasov, 2011, izvirni znanstveni članek

Opis: In this research, machine learning algorithms were compared in a landslide-susceptibility assessment. Given the input set of GIS layers for the Starča Basin, which included geological, hydrogeological, morphometric, and environmental data, a classification task was performed to classify the grid cells to: (i) landslide and non-landslide cases, (ii) different landslide types (dormant and abandoned, stabilized and suspended, reactivated). After finding the optimal parameters, C4.5 decision trees and Support Vector Machines were compared using kappa statistics. The obtained results showed that classifiers were able to distinguish between the different landslide types better than between the landslide and non-landslide instances. In addition, the Support Vector Machines classifier performed slightly better than the C4.5 in all the experiments. Promising results were achieved when classifying the grid cells into different landslide types using 20% of all the available landslide data for the model creation, reaching kappa values of about 0.65 for both algorithms.
Ključne besede: landslides, support vector machines, decision trees classifier, Starča Basin
Objavljeno: 13.06.2018; Ogledov: 15; Prenosov: 3
.pdf Celotno besedilo (382,76 KB)

86.
Lateral resistance of a short rigid pile in a two-layer cohesionless soil
Erdal Uncuoğlu, Mustafa Laman, 2011, izvirni znanstveni članek

Opis: The behavior of a laterally loaded short rigid pile founded in a two-layer sand soil profile has been investigated. For this purpose, a series of model tests were carried out on model piles. The effects of the elasticity modulus, dilatancy and interface behavior of the sand have been explored numerically by performing a series of three-dimensional non-linear finite-element analyses. The lateral load capacities in the layered sand conditions have been calculated using the methods proposed by Brinch Hansen (1961) and Meyerhof et al. (1981). The results obtained from experimental studies, numerical analyses and a conventional method were compared with each other. The results proved that the parameters investigated had a considerable effect on the behavior of short rigid piles subjected to lateral loads. It was also shown that the value of the ultimate lateral load capacity could vary significantly, depending on the methods used.
Ključne besede: lateral load, short pile, two-layered sand, model test, finite element, lateral effective stress
Objavljeno: 13.06.2018; Ogledov: 8; Prenosov: 2
.pdf Celotno besedilo (612,49 KB)

87.
Editorial
Ludvik Trauner, 2011, predgovor, spremna beseda

Ključne besede: editorials, scientific journals, geomechanics, geotechnical engineering
Objavljeno: 13.06.2018; Ogledov: 10; Prenosov: 4
.pdf Celotno besedilo (29,58 KB)
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88.
Geo-information technology for disaster risk assessment
Đorđe Ćosić, Sađan Popov, Dušan Sakulski, Ana Pavlović, 2011, izvirni znanstveni članek

Opis: The Serbian territory (including the territory of the former Yugoslavia) has been continuously exposed to different hazards, often with tragic consequences. Earthquakes and floods, usually followed by landslides, are the most dominant hazards in that region. Disaster risk reduction, prevention and early warning, as an integral part of sustainable development, do not exist in Serbia. That is one of the main reasons why the disaster-related damage is high. Despite very long experience in engineering and resources management in Serbia, there are no scientifically supported and standardized disaster risk-assessment procedures. Expertise only exists in the field of engineering-based hazard assessment. The risk-assessment method proposed in this research includes, apart from hazards, parameters such as vulnerability, exposure and safety. It considers the environmental and social components of risk management. The proposed method, implementing combined mathematical and 3D GIS tools, was applied for the Danube River, Petrovaradin (the city of Novi Sad) area, for which data were available. The relationship between the risk parameters is calculated and graphically presented. Methods like this one should contribute to a shift from a passive disaster-related defense to a proactive disaster risk management, as well as from emergency management only, to disaster prevention, preparedness and mitigation activities, in Serbia and the Western Balkan Region.
Ključne besede: hazard, vulnerability, safety, resilience, coping capacity, risk assessment, risk management, geographic information systems, earthquake, landslide, flooding, exceedance
Objavljeno: 13.06.2018; Ogledov: 10; Prenosov: 2
.pdf Celotno besedilo (418,04 KB)

89.
Fuzzy-sets decision-support system for geotechnical site soundings
Djemalddine M. Boumezerane, Smaïn Belkacemi, Bojan Žlender, 2011, izvirni znanstveni članek

Opis: A geotechnical site investigation is an important and complex task that is generally carried out in two steps. The first step, consisting of preliminary soundings, guides the subsequent site characterization. The number of soundings required to adequately characterize a site is set on the basis of an engineering judgement following the preliminary investigation, this is affected by the geological context, the area topography, the project type, and the knowledge of the neighbouring areas. A fuzzy-sets decision-support system, considering parameters that affect the number of soundings required to adequately characterize a site, is proposed. Parameter uncertainties and a lack of information are also considered. On the basis of the available qualitative and quantitative information, the proposed fuzzy system makes it possible to estimate, for a common project, the number of site soundings required to adequately characterize the site. The cases presented show that a Fuzzy Inference System can be used as a systematic decision-support tool for engineers dealing with site characterizations.
Ključne besede: geotechnical investigation, soundings number, fuzzy sets, fuzzy inference, uncertainties
Objavljeno: 13.06.2018; Ogledov: 20; Prenosov: 3
.pdf Celotno besedilo (544,70 KB)

90.
Influence of geosynthetic reinforcement on the shear strength characteristics of two-layer sub-grade
Mehrad Kamalzare, Reza Ziaie-Moayed, 2011, izvirni znanstveni članek

Opis: Due to the low bearing capacity of soft clayey soils in places that because of economic, military or geological conditions we are oblige to build a structure on, geosynthetics will be used to reinforce the soil and improve its bearing capacity. Particularly, A good example is roadways, where geosynthetics are placed between the interface of the granular materials and the soft-soil sub-grade to improve the bearing capacity of the composite layers. In previous research the behavior of one-layer soils that were reinforced with different kinds of geosynthetics were studied by experimental and analytical methods and some numerical models have been developed. In this paper the behavior of two-layer soils (granular base and clayey sub-grade) that were reinforced with some geosynthetics are investigated. Large-scale direct shear tests were performed on unreinforced and reinforced samples with different geosynthetics. The results show that depending on the characteristics of the geosynthetics, the inclusion of these materials may increase or decrease the shear strength parameters of the interface of two-layered soils. It implies that the geosynthetic-reinforced soils in the sub-base layer of roads are so sensitive to the characteristics of geosynthetics and will perform better than non-reinforced soils and consequently the load-carrying capacity of the basement will improve only if the appropriate geosynthetics are used. However, geogrid shows more reinforcement efficiency under higher vertical stresses. Increasing the relative density of the clayey sub-grade would also cause the geogrid reinforcement to be more effective.
Ključne besede: shear strength, geosynthetic, large scale direct shear test, soft clay, subgrade
Objavljeno: 13.06.2018; Ogledov: 12; Prenosov: 3
.pdf Celotno besedilo (1,52 MB)

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