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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.
41

Definición de criterios de influencia entre parámetros geotécnicos y profundidad en excavaciones, mediante la aplicación de un software de elementos finitos para la grava del conglomerado de Lima Metropolitana / Definition of Criteria of influence from Geotechnical Parameters and Depth in Excavations, through the application of a finite element’s software for the Metropolitan Lima conglomerate gravel.

Luque Aldana, Luis Alejandro, Rodríguez Manyari, Adrián Franz 31 October 2020 (has links)
La presente tesis tiene como finalidad establecer criterios de influencia entre parámetros geotécnicos y profundidad de excavaciones en suelos gravosos, mediante la aplicación de un software de elementos finitos. Para ello, se tomó como referencia a 5 estudios geotécnicos desarrollados en Lima Metropolitana (Santa Anita, San Isidro, Miraflores y San Luis), en donde se emplearon diversos ensayos con el fin de obtener parámetros necesarios para su modelación. Por ejemplo, gracias a estos estudios, se determinaron rangos a los parámetros geotécnicos (Ángulo de fricción, Cohesión y Peso Específico) que serán considerados en la modelación de los casos de estudio. De acuerdo con estos estudios, el Ángulo de Fricción oscila entre 25° y 46°; la Cohesión entre 10 kPa y 84 kPa; mientras que el Peso Específico tiene un rango de 18 kN/m3 a 24 kN/m3. Las excavaciones que serán evaluadas durante la presente investigación serán de 8m, 12m y 16m de profundidad y contarán también con rangos para el Módulo de Elasticidad (E50) y el Coeficiente de carga y descarga (Eur) necesarios para analizar el comportamiento físico del suelo. Los resultados obtenidos luego de emplear el Modelo Constitutivo Hardening Soil, fue que conforme van incrementado los Ángulos de fricción del suelo y el Módulo de Elasticidad (E50), los desplazamientos van disminuyendo poco a poco (estamos hablando de una relación inversamente proporcional). Asimismo, existe una relación directamente proporcional entre la profundidad de excavación, el módulo de elasticidad y los desplazamientos del suelo considerando un sistema de reforzamiento anclado. / The purpose of this thesis is to establish criteria of influence between geotechnical parameters and depth of excavations in burdensome soils, through the application of finite element software. For this, 5 geotechnical studies developed in Metropolitan Lima (Santa Anita, San Isidro, Miraflores and San Luis) were taken as a reference, where various tests were used in order to obtain parameters necessary for their modeling. For example, thanks to these studies, ranges were determined for the geotechnical parameters (Angle of friction, Cohesion and Specific Weight) that will be considered in the modeling of the case studies. According to these studies, the Angle of Friction ranges from 25 ° to 46 °; Cohesion between 10 kPa and 84 kPa; while the Specific Weight has a range from 18 kN / m3 to 24 kN / m3. The excavations that will be evaluated during this investigation will be 8m, 12m and 16m deep and will also have ranges for the Modulus of Elasticity (E50) and the Coefficient of loading and unloading (Eur) necessary to analyze the physical behavior of the soil. The results obtained after using the Hardening Soil Constitutive Model were that as the friction Angles of the soil and the Modulus of Elasticity (E50) increase, the displacements gradually decrease (we are talking about an inversely proportional relationship). Likewise, there is a directly proportional relationship between excavation depth, modulus of elasticity and soil displacements considering an anchored reinforcement system. / Tesis
42

Zpětná analýza sypané přehradní hráze a predikce jejího chování při mimořádných zatěžovacích stavech / Back analysis of embankment dam and prediction of its behaviour during accidental design situations

Krajčovič, Ján January 2019 (has links)
Diplomová práce představuje vytvoření softwarového 2D MKP modelu přehrady Slezská Harta v České Republice za pomoci softwaru PLAXIS 2D. V úvodu práce je analýza vodní nádrže, vytvořené jako zásobárna vody a protipovodňové dílo. Analýza sleduje geomorfologii, geologii, konstrukci tělesa hráze, použité materiály a metody, a stávající monitorovací zařízení. Pro pochopení tvorby 2D MKP modelu jsou předloženy a definované metody použitých analýz - metoda konečných prvků, analýza prosakování, materiálové modely, citlivostná analýza. Následně byla definována tvorba struktury modelu - určení posloupnosti použitých analýz, definování vstupních dat a mezních podmínek a tvorba kalibračního segmentu. V závěrečné části práce je analýza dosažených výstupů rozsáhlého testování modelu, jejich korelace s reálnými naměřenými hodnotami a celkové shrnutí přínosu vytvořeného modelu pro jeho využití při předpovídání chování přehrady v extrémních případech.
43

Výpočet sedání výškové budovy s využitím metody konečných prvků / Prediction of foundation settlement of high-rise building using the finite element method

Červenka, Jan January 2020 (has links)
The focus of this thesis is to deal with reverse engineering of high-rise building settlements. This is modeled via the finite element method performed in the Plaxis 3D program. In the first part of this thesis, a calibration of input parameters of an appropriate material model – Hardening soil – is conducted. This calibration is a result of oedometric test data which were obtained within a geotechnical survey. An influence of soils over consolidation affecting calibration and the material model choice is described. Final values of reference stiffness parameters are used in a mathematical model of the focused area. This model is created for one half of the high-rise building plan, including vestibule. The high-rise building is founded in a foundation pit. The foundations of this building consist of raft foundation and piles of jet grouting. In the model, there are also changes in pore pressure during an excavation of foundation pit included. The functional model is used for parametric analyses, namely examining cases of object´s foundations and the possible influence of foundation pit´s symmetry on the object´s settlement. All the calculated processes in the object´s settlements are then compared to data obtained from geotechnical monitoring of the structure.
44

Návrh ražby a primárního ostění tunelu na stavbě vysokorychlostního železničního spojení / Design of excavation and primary tunnel lining on high-speed railway construction

Dostál, Tomáš January 2020 (has links)
As part of modernization of the Brno-Přerov railway line, is in the section between village Blažovice and town Vyškov desined tunnel composed of two monorail tubes about 640 meters length. Tubes are situated in neogenic clay with an overburden height of 11 meters. This master thesis deals with design suitable tunnel exavation, primary lining with static calculation and geotechnical monitoring.
45

Predikce chování stříkaného betonu s využitím elastoplastického materiálového modelu / Prediction of shotcrete behavior applying elastoplastic material model

Kejík, Vít January 2020 (has links)
This work is focused on the application of advanced elasto-plastic material model intended for shotcrete. Spatial mathematical models of two laboratory tests are created, where this model is used. The first test is a three-point bending concrete specimen. Next, the behavior of the material is analyzed, in which input parameters are entered. Consequently, two reverse analyzes of the available data are analyzed where a match between prediction and measurement can be obtained. The second test is a modified tensile test, where is describe the material behavior in changing of input parameters. Subsequently, reverse data analysis is created, where an acceptable match between prediction and measurement is possible. In every study, the stress waveform in the fracture process zone is analyzed to more detail.
46

Alternativní způsoby založení kruhové nádrže v jemnozrnných zeminách / Alternative methods for foundation the circular tank in fine-grained soils

Vodáček, Ondřej January 2016 (has links)
Foundations on unbearable and yielding subsoil require such actions as to achieve both desired bearing capacity and limited settlement. Issue is presented at foundation the circular tank in saturated fine-grained soils, circular tank in Klobouky u Brna in particular. Comparison analysis is performed for alternative methods (shallow foundation, vibro stone columns, deep soil mixing, pile foundation). Differential and total settlement, time-depending analysis and baseplate stress state (bending moment, shear force) are assessed for each alternative. Pile foundation provides the best results regarding total and differential settlement, but baseplate is also under high puncture shear stress. Vibro stone columns seem suitable due to time-depending analysis of settlement, on the other hand settlement reductions are not just as good. Deep soil mixing provides satisfactory alternative for both pile foundation and vibro stone columns. Under such circumstances shallow foundation is not suitable.
47

Modelování podzemních stěn pomocí časově závislého elasto-plastického materiálového modelu / Modelling of diaphragm walls using time-dependent elasto-plastic material model

Šindelářová, Daniela January 2022 (has links)
The goal of this thesis was the verification of the advanced time-dependent elasto-plastic material model for modeling diaphragm walls. Currently, this type of construction is solved usually with a combination of linear-elastic volume and plate elements. To express time-dependent behaviour, there are both, volume and plate, elements active in short-term conditions, then only volume elements in long-term conditions, while plate elements are deactivated. In this thesis, the Shotcrete material model, which can capture the time-dependent behaviour without combining two types of construction elements, is used. First, a theory of time-dependent behaviour is presented and a design of concrete structures by Eurocode 2 is discussed. Next, the Shotcrete material model is described, then used for modeling a biaxial test and calibration of compression and bending test. Following the gained knowledge, a real boundary value problem of deep excavation supported by diaphragm walls with the strut was solved. To calculate values of the internal forces and horizontal deformation in diaphragm walls, three types of material models are used.
48

Návrh a posouzení sanace železničního náspu na Vsetínsku / Design and evaluation of the remedial works of railway embankment in Vsetín area

Vašina, Adam January 2022 (has links)
This document is focused on the elucidation of embankment deformation nearby žst. Valašská Polanka, with subsequent proposal of remediation measures, for which the own software and commercial software Plaxis 2D were used.
49

Analýza násypového tělesa na podloží zlepšeném prefabrikovanými vertikálními drény / Analysis of performance of embankment constructed on subsoil improved by vertical drains

Kováč, Vladimír January 2019 (has links)
The thesis deals with the back analysis of the instrumentated embankment on the subsoil, improved by prefabricated vertical drains. The first part is devoted to the theory of consolidation calculation. Furthermore, the author deals with a parametric study of the analytical calculation of prefabricated drains and the comparsion of the analytical and numerical solution. The last and the largest part of the work is a back analysis of the embankment which was built as a part of the subsoil improvement near the Suez Canal in Egypt by Keller GmbH.
50

Analýza metodiky pro navrhování pražcového podloží / Analysis of the procedure for design of trackbed

Svobodová, Nikola Unknown Date (has links)
The diploma thesis focuses on analysing the current Railway Infrastructure Administration methodology for designing the sleeper substructure concerning the construction's deformation resistance, its comparison with the multi-layered method, which is used in the road engineering and finite element method. It deals with various methodologies of determining the deformation resistance of the track substructure.

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