Spelling suggestions: "subject:"retaining walls."" "subject:"detaining walls.""
71 |
Electrical resistivity measurements of mechanically stabilized earth retaining wall backfillSnapp, Michael Andrew January 1900 (has links)
Master of Science / Department of Civil Engineering / Stacey Kulesza / In Kansas, mechanically stabilized earth (MSE) retaining walls are typically backfilled with coarse aggregate. Current backfill material testing procedures used by the Kansas Department of Transportation (KDOT) utilize on-site observations for construction quality assurance and the American Association of State Highway and Transportation Officials standard T 288-12 (“Standard Method of Test for Determining Minimum Laboratory Soil Resistivity”). AASHTO T 288-12 is designed to test a soil sample’s electrical resistivity (ER) that correlates to its corrosion potential. However, the test, based on material passing through a No. 10 sieve, is inappropriate for coarse aggregate typically used by KDOT as the aggregate will be retained on a No. 10 sieve and potentially leads to over-conservative designs. However, ER imaging provides a two-dimensional (2D) profile of bulk ER of backfill material, thereby yielding more information regarding backfill uniformity compared to traditional sampling. The objective of this study was to characterize bulk ER of in-place MSE wall backfill aggregate.
In this study, MSE walls selected by KDOT were tested using ER imaging during construction to determine bulk ER of the backfill. Variations within backfill ER may be a result of varying aggregate material, inclusions of fines, thoroughness of compaction, and the presence of water. ER imaging was used on five walls: four MSE walls and one gravity retaining wall that contained no reinforcement. One MSE wall contained metal reinforcement, while the other four walls contained geosynthetic. The ER imaging field method produced a 2D profile that depicted ER uniformity for bulk analysis. A post processing algorithm was generated to remove the subjective nature of the ER imaging results. The program determines the bulk ER based upon the ER imaging results. These results indicate that the laboratory analysis of AASHTO T 288-12 under-estimates the bulk ER of in-situ backfill material. Identification of a material’s bulk ER will help characterize the ER of aggregates in a complementary KDOT project. Results of this study will be used to recommend an in-situ test method for aggregate used by KDOT.
|
72 |
[en] FIELD AND LABORATORY TESTS ON THE BACKFILL OF THE EXPERIMENTAL TIRE RETAINING WALL / [es] ENSAYOS DE CAMPO Y LABORATORIO EN EL TERRAPLENADO DEL MURO EXPERIMENTAL DE NEUMÁTICOS / [pt] ENSAIOS DE CAMPO E LABORATÓRIO NO RETRO-ATERRO DO MURO EXPERIMENTAL DE PNEUSALLYSSANDRUS ELSON BARROS FONTES 10 September 2001 (has links)
[pt] Este trabalho consiste na determinação de parâmetros de
deformabilidade e resistência do solo do retro-aterro do
muro experimental de pneus, localizado em Jacarepaguá (Rio
de Janeiro). O muro experimental de pneus possui quatro
seções, das quais foram escolhidas duas para realização dos
ensaios de campo e para extração dos blocos indeformados.
Foram realizados ensaios dilatométricos e pressiométricos
no campo, e ensaios de caracterização, adensamento e
resistência ao cisalhamento no laboratório.
O programa de ensaios de cisalhamento no laboratório
consistiu de cisalhamento direto com corpo de prova na
umidade natural e submersos, ensaios triaxiais
convencionais e ensaios triaxiais com trajetória de tensão
especiais.
Uma descrição detalhada das metodologias de execução e
interpretação dos ensaios está apresentada neste trabalho,
juntamente com uma discussão dos resultados obtidos.
Em particular, a discussão enfocou os valores de tensões in
situ (coeficiente de empuxo k0) e dos módulos de
deformabilidade (módulo de Young, coeficiente de Poisson,
módulo cisalhante, dentre outros). As características de
resistências também foram analisadas, considerando-se o
solo com a umidade natural ou na condição de saturação
total.
Como principais conclusões, pode-se ressaltar que o
material compactado apresenta-se como levemente pré-
adensado, com valores de OCR menores que 2 e k0 da ordem de
0,68 a 0,70. / [en] This thesis consists of a study of stress-strain-strength
behavior of the compacted embankment constructed behind the
experimental tire wall located in Jacarepagua (Rio de
Janeiro). The experimental wall has four sections with
differet characteristics. From these, two were chosen for
the field tests and for extraction of undisturbed samples.
Dilatometer and pressuremeter were accomplished in the
field, together with characterization, consolidation and
shear resistance tests in the laboratory. The experimental
program in the laboratory consisted of direct shear on
specimens with natural moisture content and submerged
conditions. Conventional triaxial test and special stress
path tests were also performed under drained conditions.
Detailed description of the methodology and interpretation
of all tests are presented in this work, together with a
discussion of the results. In particular, the discussion
focussed on the values of in situ stresses (coefficient of
lateral stress at rest) and of the stress-strain modulus
(Young's modulus, Poisson ratio, shear modulus). The shear
strength characteristics were also analyzed, considering
both natural humidity and totally saturated specimens. From
the most significant conclusions, it can be pointed out
that the compacted material was shown to be slightly
overconsolidated, with values of OCR smaller than 2 and k0
in of the order of 0,68 to 0,70. The differences between
field and laboratory values are also discussed in the
thesis. / [es] Este trabajo consiste en la determinación de los parámetros
de deformabilidad y resistencia del suelo del terraplenado
del muro experimental de neumáticos, localizado en
Jacarepaguá (Rio de Janeiro). EL muro experimental de
neumáticos posee cuatro secciones, de las cuales fueron
seleccionadas dos para la realización de los ensayos de
campo y para la extracción de los bloques no deformados.
Fueron realizados ensayos dilatométricos y presiométricos
en campo, y ensayos de caracterización, adensamiento y
resistencia al cizallamiento en el laboratório. EL programa
de ensayos de cizallamiento en el laboratorio consistió de
cizallamiento directo con cuerpo de prueba en la humedad
natural y sumergidos, ensayos triaxiales convencionales y
ensayos triaxiales con trayectoria de tensión especial. Em
este trabajo se presenta una descripción detallada de las
metodologías de ejecución e interpretación de los ensayos,
conjuntamente con una discusión de los resultados
obtenidos. En particular, la discusión enfocó los valores
de tensiones in situ (coeficiente de empuje k0) y de los
módulos de deformabilidad (módulo de Yong, coeficiente de
Poison, módulo cizallante, dentre otros). Las
características de resistencia también fueron analizadas,
considerando el suelo con la humedad natural o en la
condición de saturación total. Como principales
conclusiones se puede resaltar que el material compactado
está levemente preadensado, con valores de OCR menores que
2 y k0 del órden de 0,68 la 0,70.
|
73 |
Análise de estabilidade de contenções, via MEF, considerando a interação solo-estrutura. / Analysis of stability of retaining walls, via MEF, regarding the soil-structure interaction.Nascimento, Alessandro Lugli 25 November 2011 (has links)
Este trabalho tem a finalidade de estudar a influência da parede de concreto na análise de estabilidade de contenções atirantadas bem como discutir sobre segurança nestas análises. Para isto foram elaborados modelos em estado plano de deformação por meio do método dos elementos finitos, MEF, para análise. A parede de concreto foi modelada com variações de rigidez e modelos reológico, com o fim de se entender sua influência no fator de segurança. Por fim foi realizado um breve estudo sobre a utilização dos métodos estatísticos na análise de estabilidade de contenções. / This work has the purpose of study the influence of the concrete wall in the stability analysis of tieback retaining walls and to discuss these safety analysis. Models were developed using plane strain state via the finite element method, FEM, for analysis. The concrete wall was modeled with variations of stiffness and rheological models, in order to bore its influence on the safety factor. Finally a brief study was conducted on the use of statistical methods in stability analysis of retaining walls.
|
74 |
Análise de estabilidade de contenções, via MEF, considerando a interação solo-estrutura. / Analysis of stability of retaining walls, via MEF, regarding the soil-structure interaction.Alessandro Lugli Nascimento 25 November 2011 (has links)
Este trabalho tem a finalidade de estudar a influência da parede de concreto na análise de estabilidade de contenções atirantadas bem como discutir sobre segurança nestas análises. Para isto foram elaborados modelos em estado plano de deformação por meio do método dos elementos finitos, MEF, para análise. A parede de concreto foi modelada com variações de rigidez e modelos reológico, com o fim de se entender sua influência no fator de segurança. Por fim foi realizado um breve estudo sobre a utilização dos métodos estatísticos na análise de estabilidade de contenções. / This work has the purpose of study the influence of the concrete wall in the stability analysis of tieback retaining walls and to discuss these safety analysis. Models were developed using plane strain state via the finite element method, FEM, for analysis. The concrete wall was modeled with variations of stiffness and rheological models, in order to bore its influence on the safety factor. Finally a brief study was conducted on the use of statistical methods in stability analysis of retaining walls.
|
75 |
The behavior of drilled shaft retaining walls in expansive clay soilsBrown, Andrew C. 06 September 2013 (has links)
Drilled shaft retaining walls are common earth retaining structures, well suited to urban environments where noise, space, and damage to adjacent structures are major considerations. The design of drilled shaft retaining walls in non-expansive soils is well established. In expansive soils, however, there is no consensus on the correct way to account for the influence of soil expansion on wall behavior. Based on the range of design assumptions currently in practice, existing walls could be substantially over- or under-designed. The goal of this research is to advance the understanding of the effects of expansive clay on drilled shaft retaining walls. The main objectives of this study are to identify the processes responsible for wall loading and deformation in expansive clay, to evaluate how these processes change with time, and to provide guidance for design practice to account for these processes and ensure adequate wall performance. The primary source of information for this research is performance data from a four-year monitoring program at the Lymon C. Reese research wall, a full-scale instrumented drilled shaft retaining wall constructed through expansive clay in Manor, Texas. The test wall was instrumented with inclinometers and fiber optic strain gauges, and performance data was recorded during construction, excavation, during natural moisture fluctuations, and during controlled inundation tests that provided the retained soil with unlimited access to water. In addition to the test wall study, a field assessment of existing TxDOT drilled shaft retaining walls was conducted. The main process influencing short-term wall deformation was found to be global response to stress relief during excavation, which causes the wall and soil to move together without the development of large earth pressures or bending stresses. Long-term wall deformations were governed by the development of drained conditions in both the retained soil and the foundation soil after approximately eight months of controlled inundation testing. To ensure adequate wall performance, the deformations and structural loads associated with short- and long-term conditions should be combined and checked against allowable values. / text
|
76 |
Architektonická studie sakrálního objektu a komunitního centra Salesiánského Brno - Líšeň / druhá etapa / Architectural study of the sacral object Brno - Líšeň / second stageŠebela, Vojtěch January 2021 (has links)
The topic of the diploma thesis is the design of the Roman Catholic Church of the Descent of the Holy Spirit in Brno Líšeň. The building will complement the needs of the Salesian community, which has been operating in the nearby Salesko youth house for almost 30 years and focuses on educating young people using methods from Don Bosco. The design of the church also envisages the construction of facilities for parishioners and accommodation for Salesians. It should also serve not only the current community, but also the general public. The design offers a solution how to modernize a building of these dimensions into an urban complex such as a housing estate in modern times. All this with an emphasis on minimizing the negative impacts on existing residents who use the surrounding areas for recreation. The building will consist of two functional units. The first will consist of a church building with a capacity of 300 seated and 100 standing parishioners. The second part will be a parish center with a community hall for 100 people. There will also be apartments for priests, a hobby workshop and parish offices.
|
77 |
Nádraží VRT letiště Brno Tuřany / HST Station at the Airport Brno TuřanySvobodová, Lenka January 2012 (has links)
Main topic of this Masters Thesis is design of railway station for high speed line railway. Building site is situated in East Moravian region in the district of Brno-Tuřany. The building is designed as a detached two-storey object standing on the bridge over the railway. Mass of the building consists of two trimmed blocks which are mutually mirrored. The mass of both parts of the building is pervaded by illuminating stripe. Its shape is also based on the shape of trimmed block and rises over the surrounding surfaces. There are placed vertical paths in the stripes. It helps passengers in orientation because these are visible even from the outside of the building. This arrangement of individual masses symbolizes both direction of the arrival of trains to the station. There is placed arrival and departure hall in the middle of the object. Its height is similar to the height of the object itself. The hall is surrounded by the service facilities of the railway station situated on two floors. The supporting structure is made of steel. Both peripheral housing and roof are supported by the frame construction consisting of planar lattice beams. Construction of the façade is composed of frame system Wicona. The peripheral housing is tiled with panels of expanded metal.
|
78 |
Συμβολή στη στατική και δυναμική ανάλυση τοίχων αντιστήριξης μέσω θεωρητικών και πειραματικών μεθόδωνΚλουκίνας, Παναγιώτης 09 July 2013 (has links)
Οι κατασκευές εδαφικής αντιστήριξης εξακολουθούν να βρίσκονται σε ευρύτατη χρήση, με διαρκώς αυξανόμενο ενδιαφέρον λόγω των απαιτήσεων των σύγχρονων έργων υποδομής αλλά και των αναγκών δόμησης σε πυκνό αστικό περιβάλλον. Το ενδιαφέρον εστιάζεται σε κατασκευαστικές λύσεις και μεθόδους σχεδιασμού που συνδυάζουν ασφάλεια και οικονομία. Η ανάλυση των συγκεκριμένων κατασκευών αντιμετωπίζει πλήθος δυσεπίλυτων προβλημάτων στο αντικείμενο της αλληλεπίδρασης εδάφους-κατασκευής που συχνά καθορίζουν τη συμπεριφορά του έργου. Η κατανόηση αυτών των μηχανισμών επιτρέπει το σχεδιασμό με μικρότερα περιθώρια αβεβαιότητας που οδηγούν σε οικονομικότερες και ορθολογικότερες λύσεις. Στην κατεύθυνση αυτή συμβάλει η παρούσα Διατριβή, με την ανάπτυξη αναλυτικών εργαλείων και θεωρητικών ευρημάτων που βοηθούν στην κατανόηση των μηχανισμών της αλληλεπίδρασης και στην εκτίμηση της συμπεριφοράς των τοίχων αντιστήριξης υπό συνδυασμένη βαρυτική και σεισμική φόρτιση. Έμφαση δίνεται στην παραγωγή απλών κλειστών λύσεων και μεθοδολογιών για τον υπολογισμό των εδαφικών ωθήσεων και τη στατική ανάλυση του συστήματος τοίχου εδάφους.
Συγκεκριμένα, παράγονται λύσεις άνω και κάτω ορίου για ενδόσιμους τοίχους, οι οποίες, παρότι προσεγγιστικές, πλεονεκτούν έναντι των κλασικών εξισώσεων Coulomb και Mononobe-Okabe τις οποίες μπορούν να αντικαταστήσουν. Σε ειδικές περιπτώσεις, όπως η περίπτωση τοίχων προβόλων με πεπλατυσμένο πέλμα, οι προτεινόμενες λύσεις οδηγούν σε ακριβή αποτελέσματα που βασίζονται σε ένα γενικευμένο πεδίο τάσεων Rankine. Επίσης παρουσιάζονται επεκτάσεις τους οι οποίες επιτρέπουν τον υπολογισμό μη-υδροστατικών κατανομών ωθήσεων γαιών λαμβάνοντας υπόψη την κυματική διάδοση της σεισμικής διέγερσης στο επίχωμα, σύμφωνα με μια ορθότερη παραλλαγή της ιδέας των Steedman & Zeng και τις διαφορετικές κινηματικές συνθήκες που προέρχονται από την απόκριση του τοίχου με περιστροφή περί την κορυφή ή τη βάση σύμφωνα με την τεχνική της Dubrova. Για την περίπτωση ανένδοτων τοίχων παρουσιάζεται μεθοδολογία για τη δραστική απλοποίηση των διαθέσιμων ελαστοδυναμικών, κυματικών λύσεων, όπως αυτή των Veletsos & Younan, η οποία καταλήγει σε κλειστές μαθηματικές εκφράσεις για τον υπολογισμό των ωθήσεων.
Τέλος, παρουσιάζονται νέα ευρήματα στην κατεύθυνση της μαθηματικής αντιμετώπισης του δυσεπίλυτου προβλήματος της οριακής ισορροπίας ριπιδίου τάσεων σε εδαφικό μέσο στο οποίο ενεργούν βαρυτικές και αδρανειακές δυνάμεις πεδίου. Η παρούσα εργασία συμβάλλει στην περαιτέρω διερεύνηση του προβλήματος το οποίο θεμελίωσαν θεωρητικά οι Levy, Boussinesq, von Karman και Caquot, μέσω της δραστικής (αλλά ακριβούς) απλοποίησης του σε μία μη-γραμμική συνήθη διαφορική εξίσωση, η οποία επιτρέπει την επίλυση με απλές αριθμητικές και ημιαναλυτικές τεχνικές. Πέρα από τα ακριβή αριθμητικά αποτελέσματα, η προτεινόμενη ανάλυση προσφέρει μια βαθύτερη εποπτεία στο πρόβλημα και ανοίγει το δρόμο για περαιτέρω διερεύνηση ή και επέκταση της μεθόδου πέρα από τα όρια της κλασικής οριακής ανάλυσης.
Η αξιοπιστία των προτεινόμενων λύσεων ελέγχεται μέσω συγκρίσεων με καθιερωμένες λύσεις και πειραματικά δεδομένα από τη βιβλιογραφία, αλλά και πρόσφατα πειραματικά αποτελέσματα που παρήχθησαν από τον συγγραφέα και ερευνητές στη σεισμική τράπεζα του Πανεπιστημίου του Bristol του Ηνωμένου Βασιλείου. / Earth retaining structures are still in widespread use, with growing interest due to the demands of modern infrastructure and building needs in a dense urban environment. Building solutions and design methodologies that combine safety and economy are the objectives of modern research. Significant difficulties in the analysis of retaining structures arise from the soil-structure interaction nature of the problem that often prescribes its behavior. Understanding these mechanisms allows design under smaller uncertainties, leading to economical and rational solutions. The contribution of the present thesis consists of the development of analytical tools and theoretical findings, helpful in understanding the mechanisms of interaction and the behavior of walls under combined gravity and seismic loading. Emphasis is given to the derivation of simple closed-form solutions and methodologies for the calculation of earth pressures and the static analysis of wall-soil system.
Specifically, approximate Lower and Upper Bound solutions are produced for the case of yielding walls, which are advantageous compared to the classical equations Coulomb and Mononobe-Okabe. In special cases, such as the L-shaped cantilever walls, these solutions lead to exact results, pertaining to a generalized Rankine stress field. Extensions of the above solutions are presented allowing the calculation of non-hydrostatic earth pressure distributions, due to the wave propagation of the seismic excitation in the backfill, according to a better variant of the Steedman & Zeng approach and different kinematic conditions of the wall rotating around the top or bottom, according to the technique of Dubrova. For the case of non-yielding walls, a new methodology for the drastic simplification of available wave solutions, such as the Veletsos & Younan, is presented which leads to closed-form expressions for the dynamic pressure calculation.
Finally, new theoretical findings are presented for the mathematical treatment of the intractable problem of plastic limit equilibrium in soil medium subjected to gravitational and inertial forces field. This work contributes to the further investigation of the problem which is founded theoretically by Levy, Boussinesq, von Karman and Caquot, through the significant (but accurate) simplification to a single, non-linear ordinary differential equation, easier to handle by simple numerical and semi-analytical techniques. Apart from the exact numerical results, the proposed analysis provides a deeper physical insight, leading the way to further investigation or extension of the method beyond the classical limit analysis assumptions.
The reliability of the proposed solutions is checked through comparisons with established solutions and experimental data from the literature and recent experimental results obtained by the author and researchers in the shake table laboratory of the University of Bristol, UK.
|
79 |
Stavebně technologický projekt ZŠ Otevřená, Brno - Žebětín / Construction technological project of elementary school Otevřená, Brno - ŽebětínNovák, Martin January 2014 (has links)
The constructive – technological project of elementary school in town district Brno – Žebětín, contains the technical report, the assessment of the wider transport relations, the time and financial plan of buildings, technological project of the site equipment, the main construction machines and mechanisms, the technological prescription for the underground construction, the inspection and test plan for the underground construction, the calculation of buildings for the objects, the safety report and the contract for work.
|
80 |
Stavebně technologický projekt terasového bytového domu v Brně / Technological project of the terrace apartment houseBaštová, Veronika January 2012 (has links)
The project deals with building technological study of the new building apartment house in Brno. Dimensions of the apartment building are 29.2 m x 57.2 m with shape of a rectangle. The apartment house is designed terraced in five floors as a brick structure of the ceramic blocks. Ceilings and construction in contact with the ground is reinforced concrete. In groundfloor are located garages, other floors are designed as residential. The project deals with technological processes of bottom building, time and financial demands of construction.
|
Page generated in 0.0665 seconds