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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Adapted data collection in field utilizing RMR and the Q-system

Olsson, Amanda January 2024 (has links)
The focus on slope stability has increased rapidly in Norway over the last years due to several unwanted landslides. In Norway, the most used method today to classify the rock mass and to determine the required reinforcement, is the Q-system. In addition to that the RMR method is also a commonly used method. However, since both the RMR and the Q-system is created to be used for underground constructions, their slope adaptations (Q-slope and SMR) has been developed. These adaptations will also be evaluated in this thesis. They will be used to examine if there is a correlation between the classification systems and the installed support on site. This thesis will only focus on slopes and not tunnels, as a limit to the scope investigated.  The joints properties at the investigated sites are taken both from engineering geologist reports and field mapping. The mapped joints will be analyzed in Dips to determine the major joint sets and by using the kinematic analysis tool determine what failure mechanisms these joint sets may create. These joint sets will be further evaluated through numerical analysis (with e.g. RocPlane, Swedge or RocTopple) dependent on their failure mechanism. The rock and joint data for calculation is gathered from three different sites, which are all part of the same project where the traffic capacity of the European route E18 through Porsgrunn, outside of Oslo, is increased. In both Blåfjell and Bjønnås the rock mass is larvikite, but in Grenland the rock mass investigated is sandstone. However, the sandstone in the Grenland has undergone contact metamorphosis, which changes the characteristics of the rock mass and creating a much stronger sandstone.  Generally, the rock mass investigated is classified to be of similar quality which gives them the same strength. Consequently, it is difficult to determine any kind of correlation between the sites. The results do not indicate the expected relationship that a stronger rock mass would need less reinforcement. In addition, it is also observed that the classification systems generally recommend more shotcrete that what is installed on site. When comparing the different classification systems, it can be seen that the Q-system generally categorize the rock mass in a lower category, indicating a weaker rock mass, compared to RMR and SMR. This then results in that the rock masses investigated is classified to be ranging from Poor to Good, dependent on the classification method.   Keywords: Rock mass classification, Q-slope, SMR, Slope stability.
82

Bio-Engineering for Land Stabilization

Kokesh, Christopher Michael 08 September 2009 (has links)
No description available.
83

Strain Compatibility Analysis in Slope Stability Modeling

Howdyshell, James Robert 25 August 2010 (has links)
No description available.
84

Evaluation of methods for rock mass characterization and design of rock slopes in crystalline rock / Utvärdering av metoder för karaktärisering av bergmassa och dimensionering av slänter i kristallint berg

Gottlander, Johanna Unknown Date (has links)
Construction of rock slopes is needed in many civil work projects. It is for example very common in road and railway cuts, but other applications include excavation for tunneling or building foundations, where perhaps sensitive constructions are present in the immediate vicinity. In Sweden the majority of the rock is hard crystalline bedrock of relatively good quality, and the fracture orientation have a large effect of the stability of the rock slope.If the geology is not properly considered for when the design of the slope is carried out, it can result in slope failure, with severe consequences. This applies especially if the rock slope is high, but unwanted effects like increased excavation and construction costs, could occur also in smaller slopes if the risks are not identified and managed. However, it is difficult to standardize design of rock slopes in fractured hard crystalline rock because of the uncertainties and variations in the geological conditions during the design phase.Rock mass characterization systems like Rock mass rating, RMR (Bieniawski 1989) and the Qsystem (Barton, Lien och Lunde 1974) are commonly used to describe the general rock mass quality. Whilst a good rock mass quality is generally easier to construct in, stability problems do occur due to structural geology in rock slopes even in good rock mass quality. The application of these systems in rock slopes can be problematic as they do not describe the geometry of the slope and how the fractures daylight in the slope face. Instead, stereonets can be used to visualize this, but fracture parameters of large importance for stability (persistence, roughness and alteration) are traditionally not presented in a stereonet analysis. Additionally, these parameters and the structural geological conditions can be difficult to predict and can vary significantly over short distances, why it can be difficult to forecast and predict failure in the design face.Slope instability due to large sliding and wedge failures have been observed in a large number of slopes in crystalline rock, and a standard method for design of rock slopes is lacking. This has given rise to the research question of how best to describe rock mass conditions, how to design slopes in crystalline rock and how to manage these risks during construction.To investigate this, three rock slopes where large failure had occurred were selected for the case study and were mapped, characterized and analyzed. The results from the case study showed that all rock slopes investigated had in common that failure had occurred along fractures of large persistence. This highlights the importance of evaluating the geology in the correct scale and suggest that lineament studies and other elevation based interpretation are perhaps more useful than previously thought. It also came to light that the planning and design process is inflexible which in many cases lead to large risks being overlooked or left unnoticed.A flow chart for risk classification was produced and suggested for aid in decision making aiming at simplifying project management of rock slopes, as well as aiding in visualization of the risk that rock slopes can be associated to.
85

Lateral Resistance of Piles at the Crest of Slopes in Sand

Mirzoyan, Artak Davit 29 August 2007 (has links) (PDF)
Pile foundations near the crest of a slope are often required to resist lateral loads. This is particularly important for piles at the abutments of bridges. However, limited full-scale test data are available to indicate how the lateral resistance of a pile would be affected when it is located near the crest of a slope. To investigate the effect of a slope on lateral pile resistance, three full scale lateral load tests were conducted on an instrumented steel pipe pile. For the first test, the pile was laterally loaded in horizontal ground. For the second test the pile was at the crest of a 30 degree slope and in the third test the pile was placed three diameters behind the crest of the 30 degree slope. The soil around the pile consisted of clean sand compacted to about 95% of the modified Proctor maximum unit weight for all three tests. Laboratory and in-situ direct shear tests indicated that the friction angle of the sand was approximately 39 degrees. The pile was instrumented with strain gages at approximately 1.5 ft intervals along its length so that the bending moment versus depth profile could be determined. Pile head load, deflection, and rotation were also measured. Based on the results, the presence of the slope decreased the ultimate lateral resistance of the pile-soil system by approximately 25% and 10% for tests two and three, respectively. The presence of the slope also resulted in an increase in the maximum bending moment of approximately 40% and 30% for tests two and three, respectively. Analyses using LPILE matched the lateral resistance for the pile in horizontal ground, but significantly overestimated the decrease in resistance due to the sloping ground. A mathematical model was developed to predict the ultimate strength of a pile located some distance from the crest of a cohesionless sloping profile. Parametric test results using the model were within 2.6 % of the measured results of tests two and three.
86

CVSD MODULATOR USING VHDL

Hicks, William T., Yantorno, Robert E. 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / IRIG-106 Chapter 5 describes a method for encoding voice using a simple circuit to reduce the overall bit rate and still achieve good quality voice. This well described Continuously Variable Slope Delta Modulation (CVSD) circuit can be obtained using analog parts. A more stable implementation of CVSD can be obtained by designing an anti-aliasing input filter, an A/D converter, and logic. This paper describes one implementation of the CVSD using a standard A/D converter and logic.
87

DESIGN OF A DIGITAL VOICE ENCODER CIRCUIT

Olyniec, Lee 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / This paper describes the design and characteristics of a digital voice encoding circuit that uses the continuously variable slope delta (CVSD) modulation/demodulation method. With digital voice encoding, the audio signal can be placed into the pulse code modulation (PCM) data stream. Some methods of digitizing voice can require a large amount of bandwidth. Using the CVSD method, an acceptable quality of audio signal is obtained with a minimum of bandwidth. Presently, there is a CVSD microchip commercially available; however, this paper will describe the design of a circuit based on individual components that apply the CVSD method. With the advances in data acquisition technology, increased bit rates, and introduction of a corresponding MIL-STD, CVSD modulated voice will become more utilized in the flight test programs and a good knowledge of CVSD will become increasingly important. This paper will present CVSD theory, supported by graphical investigations of a working circuit under different conditions. Finally, several subjects for further study into CVSD will be addressed.
88

Ευστάθεια υψηλών πρανών σε ασβεστολιθική βραχομάζα: Εφαρμογή σε περιοχές υψηλού κινδύνου της Ε.Ο. Πατρών-Τριπόλεως / Limestone slope stability in high-risk areas of Patras-Tripolis national road

Κάτσικα, Πηνελόπη 11 July 2013 (has links)
Διερευνώνται οι συνθήκες ευστάθειας σε συγκεκριμένα πρανή επί της Ε.Ο. Πατρών – Τριπόλεως αμέσως μετά τον οικισμό Δίβρη. Για τον σκοπό αυτό, έγινε λεπτομερής μηχανική περιγραφή των ασυνεχειών, ταξινομήσεις βραχομάζας με τα συστήματα RMR και GSI καθώς επίσης και συστηματική δειγματοληψία βραχωδών ασβεστολιθικών τεμαχών μεγάλων διαστάσεων. Τα δείγματα αυτά μεταφέρθηκαν στο Εργαστήριο Τεχνικής Γεωλογίας, για διάτρηση και κοπή, ώστε να διαμορφωθούν κυλινδρικά δοκίμια κατάλληλα για την εκτέλεση εργαστηριακών δοκιμών τριαξονικής φόρτισης, μοναξονικής θλίψης, σκληρότητα Schmidt, σημειακή φόρτιση, διάτμηση ασυνεχειών κ.λπ. Με δεδομένα, τα αποτελέσματα της εργαστηριακής έρευνας αλλά και τις επιτόπου παρατηρήσεις και καταγραφές, εκτιμήθηκαν τα μοντέλα δυνητικών ολισθήσεων στα ασβεστολιθικά πρανή, ενώ με την εφαρμογή μεθόδων οριακής ισορροπίας μελετήθηκε η ευστάθειά τους. Προς την κατεύθυνση αυτή χρησιμοποιήθηκαν τα λογισμικά WEDGE και ROCSTA του Εργαστηρίου Τεχνικής Γεωλογίας καθώς και το Swedge και RocPlane της Rocscience, για τις περιπτώσεις σφηνοειδών και επιπέδων ολισθήσεων αντίστοιχα. Τέλος, έγινε σύγκριση των αποτελεσμάτων προσομοίωσης των παραπάνω λογισμικών και εξήχθησαν ενδιαφέροντα συμπεράσματα σχετικά με την εφαρμογή τους και τις δυνατότητες ρεαλιστικού σχεδιασμού των μέτρων προστασίας. / In this postgraduate work an effort is presented to apply computational methods of Laboratory of Engineering Geology in order to analyze Limestone slope stability in high-risk areas of Patras - Tripolis national road and to design reliable, safe, preventive and protective measures. The geological conditions of the area including the geotectonic evolution of geological Olonou - Pindos zone are described. The discontinuities were examined in detail, while the rock mass quality, was estimated using classification system such as RMR, SMR and GSI systems. The topographic map of the region of interest was outlining with a brief description of georeferencing and GIS software. It is necessary to note separate chapters of the work, were focused on stability and analysis using several software, Rocksta, RocPlane of Rocscience, Wedge, Swedge of Rocscience, Dips. Finally, a comparative overview of these programs and drawing conclusions is included.
89

Ευστάθεια βραχωδών πρανών του ορύγματος Περιθώρι Αιτωλοακαρνανίας

Κλημεντίδη, Κυριακή 14 October 2013 (has links)
H παρούσα εργασία αφορά τη διερεύνηση ευστάθειας των πρανών του ορύγματος στη Χ.Θ. 18+535 –18+832 της Ιόνιας Οδού. Στην περιοχή αυτή προβλέπεται να εκσκαφτεί μονόπλευρο όρυγμα επί της κύριας οδού (αριστερό πρανές), μέγιστου κατακόρυφου ύψους 30m. Στην δεξιά παρειά θα κατασκευαστεί τοίχος από οπλισμένο έδαφος για την αντιστήριξη του αυτοκινητοδρόμου και της βοηθητικής οδού. Στην περιοχή εκτελέστηκαν έξι γεωτρήσεις (BE1-139, BW6-610, BC4-435, BC4-436, BW4-437, BC4-438, BW4-439) στην παρούσα φάση μελέτης και μία γεώτρηση (ΓΓ4) και δύο φρέατα (Φ3 και Φ4) σε προγενέστερο στάδιο έρευνας. Σύμφωνα με τα αποτελέσματα των γεωτεχνικών ερευνών η περιοχή αποτελείται από φλύσχη και πιο συγκεκριμένα από εναλλαγές ψαμμίτη και κροκαλοπαγούς. Οι γεωτρήσεις που εκτελέστηκαν στην περιοχή του ορύγματος έδειξαν επιφανειακά και μέχρι το βάθος του 1.00μ το μανδύα αποσάθρωσης του υποκείμενου κροκαλοπαγούς αποτελούμενου από κροκάλες και αργιλοϊλυώδεις χάλικες με άμμο, χαμηλής πλαστικότητας έως μη πλαστικούς, πολύ πυκνής απόθεσης. Έπειτα από το βάθος αυτό και μέχρι το πέρας των γεωτρήσεων το βραχώδες υπόβαθρο αποτελείται από ψαμμίτες και κροκαλοπαγή σε εναλλαγές. Ο προσανατολισμός των συστημάτων διακλάσεων και κυρίως της στρώσης κρίνεται δυσμενής λόγω δημιουργίας δυνητικών επιπέδων ολίσθησης και σφηνών. Επιπλέον λαμβάνεται υπόψη η επιδεκτικότητα στην αποσάθρωση που παρουσιάζει ο φλύσχης ως υλικό, όταν εκτεθεί σε περιβαλλοντικούς παράγοντες με την πάροδο του χρόνο, σε συνδυασμό με απότομες κλίσεις πρανών. Ο σχεδιασμός των πρανών έγινε με στόχο την επίτευξη αποδεκτών συντελεστών ασφαλείας έναντι επίπεδης ολίσθησης, ολίσθησης σφηνοειδούς τύπου και ανατροπών στις περιοχές όπου τα πρανή διαμορφώνονται σε κερματισμένη βραχόμαζα, αλλά και κυκλικής ολίσθησης όπου τα πρανή θα εκσκαφτούν εντός εδαφοποιημένων υλικών. Επιπλέον αποσκοπεί στην εκσκαφή των πρανών σε ασφαλείς κλίσεις και τον περιορισμό της έκτασης των εκσκαφών για περιβαλλοντικούς κυρίως λόγους. Για την εκσκαφή των ορυγμάτων με κλίση 3:1 προκύπτει πρόβλημα δυνητικών ολισθήσεων και θα πρέπει να κατασκευαστούν μέτρα αντιστήριξης καθώς και μέτρα αποστράγγισης. Τα απαιτούμενα μέτρα αντιστήριξης και αποστράγγισης και προστασίας από διάβρωση και αποσάθρωση αναλύονται και παρουσιάζονται στην παρούσα μελέτη. / -
90

Dynamika a rozšíření recentních svahových pohybů na úpatí Krušných hor / Dynamics and spatial extension of recent landslides at the foot of Krušné Hory Mts.

Burda, Jan January 2012 (has links)
Dynamika a rozšíření recentních svahových pohybů na úpatí Krušných hor | Abstrackt 1 ABSTRACT Recent mass movements currently comprise one of the main morphogenetic processes in the extensive anthropogenic relief of the foreground of the Krušné Hory Mountains in the Czech Republic. These mass movements result in several types of deep- seated slope failures, depending on the type of movement, lithological, structural, and geotechnical conditions and the water saturation of the landslide material. This thesis presents broad set of various methods of geomorphology, geophysics, engineering geology, dendrogeomorphology and geodesy in an attempt to fully understand the problem of slope failures in the Jezeří area located at the boundary between the Krušné Hory Mountains and the Most Basin (Czech Republic). An interdisciplinary approach has enabled an in-depth review of both the dynamics and development of recent slope failures as well as morphology and structure of slope failures. There are two sectors - Southeast and Southwest - with different types of slope failures. In the Southwest sector, mass movements occur in thick colluvial mantle and weathered Tertiary claystones. The main factors influencing their development include rainfall culminations, groundwater flowing from the valley of Šramnický Brook and...

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