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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.
1

Determination and applications of rock quality designation (RQD)

Zhang, Lianyang 06 1900 (has links)
Characterization of rock masses and evaluation of their mechanical properties are important and challenging tasks in rock mechanics and rock engineering. Since in many cases rock quality designation (RQD) is the only rock mass classification index available, this paper outlines the key aspects on determination of RQD and evaluates the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses. First, various methods for determining RQD are presented and the effects of different factors on determination of RQD are highlighted. Then, the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses are briefly reviewed. Finally, the empirical methods based on RQD are used to determine the deformation modulus and unconfined compressive strength of rock masses at five different sites including 13 cases, and the results are compared with those obtained by other empirical methods based on rock mass classification indices such as rock mass rating (RMR), Q-system (Q) and geological strength index (GSI). It is shown that the empirical methods based on RQD tend to give deformation modulus values close to the lower bound (conservative) and unconfined compressive strength values in the middle of the corresponding values from different empirical methods based on RMR, Q and GSI. The empirical methods based on RQD provide a convenient way for estimating the mechanical properties of rock masses but, whenever possible, they should be used together with other empirical methods based on RMR, Q and GSI. (C) 2016 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V.
2

Spraustinio giliojo standaus pamato pagrindo įtempių ir deformacijų būvis / Driven deep rigid foundation base stress and strain state

Statkus, Tautvydas 11 June 2014 (has links)
Baigiamajame magistro darbe nagrinėjami giliojo pamato, įsprausto į smėlinį gruntą, nuosėdžiai nuo pamato viršuje pridėtos apkrovos. Darbe apžvelgtos jėgos perdavimo pamato pagrindui, kontaktinių įtempių pasiskirstymo, taip pat įtempių pasiskirstymo pamato pagrinde teorinės prielaidos, aprašyta vienuolika nuosėdžių skaičiavimo metodų. Tiriamojoje darbo dalyje aprašomos fizinės ir mechaninės pagrindo savybės, analizuojami statiniai polio bandymai. Išnagrinėjus teorinių prielaidų, bandymų ir lyginamųjų skaičiavimų rezultatų atitikimą, pateikiamos baigiamojo darbo išvados ir siūlymai. Darbą sudaro aštuonios dalys: įvadas, polio sąveika su pagrindu, polio, apkrauto vertikalia gniuždančiąja jėga, nuosėdžių skaičiavimo metodų apžvalga, fizinės ir mechaninės pagrindo savybės, statiniai polio bandymai, apskaičiuotų ir bandymų metu nustatytų rezultatų palyginimas, išvados ir siūlymai, literatūros sąrašas. Darbo apimtis – 86 p. be priedų, 81 pav., 10 lent. / In master thesis examined settlement of deep foundation in cohesion less soil. Theoretical assumptions of vertical force transmission for the soil, stress distribution in the base of the deep foundation, interactional stresses, was overviewed in the work. Eleven methods for settlement determination of deep foundation was described also. In the part of exploratory work, the description of test was made. Main differences of the methods obtained and test data with calculated values compared. Conclusions and proposals for further investigation represented. Structure: introduction, soil pile interaction, single pile settlement, physical and mechanical properties of basement, comparison of determined and calculated values, conclusions and suggestions, references. Thesis consist of: 86 p. text without appendixes, 81 pictures, 10 tables.
3

Previsão da curva tensão-recalque de ensaios de placa em solo não saturado / Stress-settlement curve prediction of plate load tests on unsaturated soil

Menegotto, Mauro Leandro 07 April 2004 (has links)
Apresenta-se um método para a previsão da curva tensão-recalque a ser obtida em provas de carga em placa circular, instalada a diferentes profundidades e com vários diâmetros, para diversos níveis de sucção em solo não saturado. Também é proposto um procedimento para correção dos recalques medidos em ensaio com carregamento do tipo rápido, para a obtenção dos correspondentes recalques estabilizados de um ensaio lento. A previsão realizada apresenta resultados bastante próximos dos obtidos em provas de carga, verificando-se assim a aplicabilidade do método proposto para reproduzir o comportamento do sistema solo-placa neste tipo de solo. Além disso, este trabalho apresenta um estudo do módulo de deformabilidade a partir de ensaios de campo e de laboratório, para o solo do campo experimental de fundações da EESC/USP, aplicando conceitos da mecânica dos solos não saturados. Em campo, o módulo de deformabilidade foi obtido por meio de provas de carga em placa circular com e sem inundação prévia do solo. Em laboratório, o módulo foi obtido a partir de ensaios de compressão confinada e triaxiais, ambos com sucção controlada. Observou-se que a sucção matricial tem grande influência no módulo de deformabilidade do solo. / This thesis presents a method for prediction the stress-settlement curve to be obtained in circular plate load tests, at different depths and with several diameters, to differents suction levels on unsaturated soil. A procedure is also proposed for correction the settlement measured with a quick maintained load (QML) tests to obtain the stabilized settlement in a slow maintained load (SML) tests. This prediction presents quite results of the real measured stress-settlement curve through load tests, thus verifying the applicability of the proposed method to reproduce the behavior the soil-plate system in this soil. Besides, this work presents a study of the deformation modulus using field and laboratory tests, to the soil of the foundations experimental field of EESC/USP, applying concepts of the unsaturated soil mechanics. In field, the deformation modulus was obtained by means of circular plate load tests with and without previous soaking of the soil. In laboratory, the modulus was obtained using confined compression and triaxial tests, both with controlled suction. It was observed that the matric suction has great influence in the soil deformation modulus.
4

Previsão da curva tensão-recalque de ensaios de placa em solo não saturado / Stress-settlement curve prediction of plate load tests on unsaturated soil

Mauro Leandro Menegotto 07 April 2004 (has links)
Apresenta-se um método para a previsão da curva tensão-recalque a ser obtida em provas de carga em placa circular, instalada a diferentes profundidades e com vários diâmetros, para diversos níveis de sucção em solo não saturado. Também é proposto um procedimento para correção dos recalques medidos em ensaio com carregamento do tipo rápido, para a obtenção dos correspondentes recalques estabilizados de um ensaio lento. A previsão realizada apresenta resultados bastante próximos dos obtidos em provas de carga, verificando-se assim a aplicabilidade do método proposto para reproduzir o comportamento do sistema solo-placa neste tipo de solo. Além disso, este trabalho apresenta um estudo do módulo de deformabilidade a partir de ensaios de campo e de laboratório, para o solo do campo experimental de fundações da EESC/USP, aplicando conceitos da mecânica dos solos não saturados. Em campo, o módulo de deformabilidade foi obtido por meio de provas de carga em placa circular com e sem inundação prévia do solo. Em laboratório, o módulo foi obtido a partir de ensaios de compressão confinada e triaxiais, ambos com sucção controlada. Observou-se que a sucção matricial tem grande influência no módulo de deformabilidade do solo. / This thesis presents a method for prediction the stress-settlement curve to be obtained in circular plate load tests, at different depths and with several diameters, to differents suction levels on unsaturated soil. A procedure is also proposed for correction the settlement measured with a quick maintained load (QML) tests to obtain the stabilized settlement in a slow maintained load (SML) tests. This prediction presents quite results of the real measured stress-settlement curve through load tests, thus verifying the applicability of the proposed method to reproduce the behavior the soil-plate system in this soil. Besides, this work presents a study of the deformation modulus using field and laboratory tests, to the soil of the foundations experimental field of EESC/USP, applying concepts of the unsaturated soil mechanics. In field, the deformation modulus was obtained by means of circular plate load tests with and without previous soaking of the soil. In laboratory, the modulus was obtained using confined compression and triaxial tests, both with controlled suction. It was observed that the matric suction has great influence in the soil deformation modulus.
5

Požeminių polimerinių talpų sąveika su gruntu / Soil-structure interaction of buried polymer vessels

Mikolainis, Mindaugas 01 August 2012 (has links)
Šiame darbe susisteminti ir palyginti pagrindiniai grunto standumo koeficientų nustatymo metodai. Aprašoma metodika, kaip iš grunto santykinio tankio galima apskaičiuoti dinaminį bei statinį tamprumo modulius. Pateikiamos šių grunto parametrų koreliacinės priklausomybės. Eksperimentiniais tyrimais įrodyta, kad silpnuose gruntuose egzistuoja netiesinė grunto tamprumo modulio priklausomybė nuo šalia grunto esančios priekrovos. Priekrovą traktuojant kaip tiesiškai priklausančią nuo gylio, išvesta tamprumo modulio silpnuose gruntuose priklausomybė nuo gylio. Rezervuarų skaičiavimui buvo pasinaudota 2 panašių konstrukcijų skaičiavimo metodikomis (tunelių metodika bei vamzdžių m.). Taip pat pasinaudota СНиП 2.06.09-84 tunelių projektavimo nurodymais. Konstrukcija sumodeliuota projektavimo programomis Robot Structural Analysis Pro, SCAD, Plaxis 2D. Taip pat pateiktas patobulintas modelis, atramas išskirstant į ploto vienetą, autoriaus nuomone, tinkamesnėmis plonasienėms mažo standumo konstrukcijoms. Skaičiuotiniuose modeliuose įvertinami visi pagrindiniai rezervuarų konstrukciniai elementai: galiniai kupolai, lengvosios sąstandos, špangautai. Laboratoriniais bandymais nustatytos ir įvertintos polimerinio kompozito konstrukcinės savybės: virtualus tamprumo modulis, Puasono koeficientas, valkšnumo koeficientas bei senėjimo faktorius. Išvadose apibendrinami rezultatai, taip pat suformuojami pasiūlymai, naudingi tolesniems tiriamiesiems darbams, bei panašių konstrukcijų... [toliau žr. visą tekstą] / Main methods to determine subgrade reaction is systemized in this master thesis work. Determination of static and dynamic deformation modulus, when relative soil density is known, are also familiarized. Correlation between the parameters is given in section 2. Experiments were made to prove that there is a link between deformation modulus and surcharge. If surcharge depends linearly from depth, then a function was created to predict deformation modulus values in weak soil when depth varies. 2 similar construction (pipes and tunnels) methods were used to design a buried tank. Design model was created by these design programs: Robot Structural Analysis Pro, SCAD, and PLAXIS 2D. An additional tank modelling method has been suggested by the author. Supports were assigned in plane instead of in a straight line. The updated model seems to better fit for low stiffness construction materials like GRP composites. In these design models all common tank structural elements were included: longitude domes, light and heavy stiffeners, orthotropic material. Main design parameters like virtual elastic modulus, Poisson ratio, creep factor, factor of durability. Results are summarized in conclusions. Suggestions were provided to help future researchers and designers with this kind of problems: structural design of composite polymer structures, design of buried thin-shelled tanks and evaluation of deformation modulus.
6

Technologie zur ortsnahen und energieeffizienten Suspensionsherstellung unter Verwendung von Stützkorn zum dauerhaften Bergversatz

Cramer, Kay 11 June 2020 (has links)
In der Arbeit erfolgen Untersuchungen einer neuartigen Materialkombination hinsichtlich ihrer Eignung als Füllmaterial für alte Bergwerksstollen zum dauerhaften Verfüllen dieser Stollen. Dazu wird ein vorhandenes Füllmaterial dahingehend modifiziert, dass es einer höheren Belastung durch den entstehenden Gebirgsdruck besser standhält. Eine Versuchsanlage für den Einsatz unter Tage wird dafür konzipiert um verschiedene Stoffgemische mit Hilfe eines Strahlrohres vor Ort herzustellen und damit Versuchsstollen zu füllen. In diesem Zusammenhang wird das Prinzip des Strahlrohres näher erläutert und ein auf die Bedingungen und Fördermengen angepasstes Strahlrohr ausgelegt, konstruiert und getestet. Parallel dazu werden mit dem gleichen Füllmaterial im Labor verschiedene Festigkeitsuntersuchungen durchgeführt. Im Anschluss wurde der Aushärtevorgang in den Teststollen dokumentiert und ausgewertet.:1. Einleitung 2. Zielstellung und Abgrenzung der Arbeit 2.1. Ziel der Arbeit 2.2. Lösungsansatz 2.3. Abgrenzung der Arbeit 3. Grundlagen 3.1. Versatzbergbau in Bernterode 3.2. Bewegungsverhältnisse im Suspensionsrohr unter Tage 3.3. Siebklassierung 3.3.1. Analyse 3.3.2. Produktionssiebung 3.4. Statischer Mischer 3.5. Strahlrohr - Funktionsprinzip 4. Realisierung der Steinsalzzugabe 4.1. Auslegung des Strahlrohres 4.1.1. Vorbemerkung 4.1.2. Richtlinien zur Auslegung 4.1.3. Berechnung des Strahlrohres 4.2. Auslegung des statischen Mischers 4.2.1. Auswahl des Mischertyps und Variantenbetrachtung 4.2.2. Berechnung 5. Analytische Untersuchungen 5.1. Grundrezeptur für die Suspension 5.2. Untersuchung des eingesetzten Halits 5.2.1. Klassierung des Halits 5.2.2. Analyse des Halits 5.2.3. Bestimmung weiterer Parameter 5.2.4. Mikroskopische Aufnahmen des Salzes 5.3. Labortechnische Untersuchungen 5.4. Druckfestigkeitsuntersuchungen im Labormaßstab 5.4.1. Beschreibung der Laborversuche 5.4.2. Probenvorbereitung 5.4.3. Durchführung der Druckversuche 5.4.4. Durchführung Langzeitlagerung 6. Experimentelle Untersuchungen unter Tage 6.1. Übersicht 6.2. Versuchsaufbau unter Tage 6.2.1. Vorversuche 6.2.2. Dauerversuche 6.3. In-situ-Versuche 6.4. Ex-situ-Versuche 7. Auswertung 7.1. Stützkornzugabe mit Hilfe eines Strahlrohres 7.2. Einaxialer Druckversuch 7.2.1. Probenvorbereitung 7.2.2. Druckversuch 7.2.3. Druckversuch Langzeitlagerung über 20 Wochen 7.2.4. Mikroskopische Aufnahmen der Bruchflächen 7.2.5. Materialfeuchtemessung 7.2.6. Materialfeuchtemessung Langzeitlagerung 7.3. In-situ-Untersuchungen 7.3.1. Messung des Verformungsmoduls Evd 7.3.2. Dichtemessungen der ausdrainierten Abschnitte 8. Zusammenfassung und Ausblick 9. Literaturverzeichnis 10. Abbildungsverzeichnis 11. Tabellenverzeichnis 12. Anlagen 12.1. Geschichte des Salzbergbaus 12.2. Begriffsdefinition – Suspension 12.3. Statischer Mischer 12.4. Technische Zeichnungen des Strahlrohres 12.5. Ergebnis der Klassierung des eingesetzten Halits 12.6. Protokoll Spülversuch Stützkorn am 15.3.2016 12.7. Protokoll einaxialer Druckversuch Labormaßstab 12.8. Protokoll einaxialer Druckversuch – Langzeitlagerung / The thesis concentrates on the research of a new material combination regarding its usefulness as a long-term filling material for old mines. Already existing filling material was modified in a way to withstand a bigger rock pressure. After a brief introduction of mining in Central Germany, resulting in the necessity of using such a technology, the established process this thesis is based on will be described in greater detail. Further, important terminology and employed technology will be clarified. Based upon this, an underground test facility is designed in order to produce different substance mixtures with the help of a radiant tube to fill the test tunnels. In this context, the principle of the radiant tube will be further clarified. The radiant tube, adjusted to the conditions and delivery rates, will then be constructed and tested. At the same time, the same filling material will be thoroughly tested in a laboratory regarding its strength and cohesiveness. Subsequently, the hardening process in the tunnels underground will be documented and evaluated.:1. Einleitung 2. Zielstellung und Abgrenzung der Arbeit 2.1. Ziel der Arbeit 2.2. Lösungsansatz 2.3. Abgrenzung der Arbeit 3. Grundlagen 3.1. Versatzbergbau in Bernterode 3.2. Bewegungsverhältnisse im Suspensionsrohr unter Tage 3.3. Siebklassierung 3.3.1. Analyse 3.3.2. Produktionssiebung 3.4. Statischer Mischer 3.5. Strahlrohr - Funktionsprinzip 4. Realisierung der Steinsalzzugabe 4.1. Auslegung des Strahlrohres 4.1.1. Vorbemerkung 4.1.2. Richtlinien zur Auslegung 4.1.3. Berechnung des Strahlrohres 4.2. Auslegung des statischen Mischers 4.2.1. Auswahl des Mischertyps und Variantenbetrachtung 4.2.2. Berechnung 5. Analytische Untersuchungen 5.1. Grundrezeptur für die Suspension 5.2. Untersuchung des eingesetzten Halits 5.2.1. Klassierung des Halits 5.2.2. Analyse des Halits 5.2.3. Bestimmung weiterer Parameter 5.2.4. Mikroskopische Aufnahmen des Salzes 5.3. Labortechnische Untersuchungen 5.4. Druckfestigkeitsuntersuchungen im Labormaßstab 5.4.1. Beschreibung der Laborversuche 5.4.2. Probenvorbereitung 5.4.3. Durchführung der Druckversuche 5.4.4. Durchführung Langzeitlagerung 6. Experimentelle Untersuchungen unter Tage 6.1. Übersicht 6.2. Versuchsaufbau unter Tage 6.2.1. Vorversuche 6.2.2. Dauerversuche 6.3. In-situ-Versuche 6.4. Ex-situ-Versuche 7. Auswertung 7.1. Stützkornzugabe mit Hilfe eines Strahlrohres 7.2. Einaxialer Druckversuch 7.2.1. Probenvorbereitung 7.2.2. Druckversuch 7.2.3. Druckversuch Langzeitlagerung über 20 Wochen 7.2.4. Mikroskopische Aufnahmen der Bruchflächen 7.2.5. Materialfeuchtemessung 7.2.6. Materialfeuchtemessung Langzeitlagerung 7.3. In-situ-Untersuchungen 7.3.1. Messung des Verformungsmoduls Evd 7.3.2. Dichtemessungen der ausdrainierten Abschnitte 8. Zusammenfassung und Ausblick 9. Literaturverzeichnis 10. Abbildungsverzeichnis 11. Tabellenverzeichnis 12. Anlagen 12.1. Geschichte des Salzbergbaus 12.2. Begriffsdefinition – Suspension 12.3. Statischer Mischer 12.4. Technische Zeichnungen des Strahlrohres 12.5. Ergebnis der Klassierung des eingesetzten Halits 12.6. Protokoll Spülversuch Stützkorn am 15.3.2016 12.7. Protokoll einaxialer Druckversuch Labormaßstab 12.8. Protokoll einaxialer Druckversuch – Langzeitlagerung

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