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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.
261

Response of riparian cottonwoods to experimental flows along the lower Bridge River, British Columbia

Hall, Alexis Anne, University of Lethbridge. Faculty of Arts and Science January 2007 (has links)
The Bridge River drains the east slope of the Coast Mountain Range and is a major tributary of the Fraser River in southwestern British Columbia. The lower Bridge River has been regulated since the installation of Terzaghi Dam in 1948, which left a section of dry riverbed for an interval of 52 years prior to 2000. An out-of-court settlement between BC Hydro and Federal and Provincial Fisheries regulatory agencies resulted in the required experimental discharge of 3 m3/s below Terzaghi Dam in 2000. This study investigated growth of black cottonwood (Populus trichocarpa) trees in response to the experimental discharges. Mature trees did not show a significant response in radial trunk growth or branch elongation. In contrast, the juvenile trees displayed an increased growth response, and the successful establishment of saplings provided a dramatic response to the new flow regime. Thus, I conclude that cottonwoods have benefited from the experimental flow regime of the lower Bridge River. / xii, 89 leaves : ill. (some col.) ; 29 cm
262

Response of cable-stayed and suspension bridges to moving vehicles : Analysis methods and practical modeling techniques

Karoumi, Raid January 1998 (has links)
This thesis presents a state-of-the-art-review and twodifferent approaches for solving the moving load problem ofcable-stayed and suspension bridges. The first approach uses a simplified analysis method tostudy the dynamic response of simple cable-stayed bridgemodels. The bridge is idealized as a Bernoulli-Euler beam onelastic supports with varying support stiffness. To solve theequation of motion of the bridge, the finite difference methodand the mode superposition technique are used. The second approach is based on the nonlinear finite elementmethod and is used to study the response of more realisticcable-stayed and suspension bridge models considering exactcable behavior and nonlinear geometric effects. The cables aremodeled using a two-node catenary cable element derived using"exact" analytical expressions for the elastic catenary. Twomethods for evaluating the dynamic response are presented. Thefirst for evaluating the linear traffic load response using themode superposition technique and the deformed dead load tangentstiffness matrix, and the second for the nonlinear traffic loadresponse using the Newton-Newmark algorithm. The implemented programs have been verified by comparinganalysis results with those found in the literature and withresults obtained using a commercial finite element code.Several numerical examples are presented including one for theGreat Belt suspension bridge in Denmark. Parametric studieshave been conducted to investigate the effect of, among others,bridge damping, bridge-vehicle interaction, cables vibration,road surface roughness, vehicle speed, and tuned mass dampers.From the numerical study, it was concluded that road surfaceroughness has great influence on the dynamic response andshould always be considered. It was also found that utilizingthe dead load tangent stiffness matrix, linear dynamic trafficload analysis give sufficiently accurate results from theengineering point of view. / QC 20100511
263

Most přes potok Hluchová - stavebně technologický projekt / The bridge over the creek Hluchova - building and technological project

Trochta, Ondřej January 2018 (has links)
The diploma thesis deals with the construction of the technical project of the SO210 bridge over the stream Hluchová on the I / 11 road. The bridge is designed as reinforced concrete, additionally prestessed with a length of 70m. The thesis was processed within the scope of DP assignment.
264

Application of monitoring to dynamic characterization and damage detection in bridges

Gonzalez, Ignacio January 2014 (has links)
The field of bridge monitoring is one of rapid development. Advances in sensor technologies, in data communication and processing algorithms all affect the possibilities of Structural Monitoring in Bridges. Bridges are a very critical part of a country’s infrastructure, they are expensive to build and maintain, and many uncertainties surround important factors determining their serviceability and deterioration state. As such, bridges are good candidates for monitoring. Monitoring can extend the service life and avoid or postpone replacement, repair or strengthening works. The amount of resources saved, both to the owner and the users, by reducing the amount of non-operational time can easily justify the extra investment in monitoring. This thesis consists of an extended summary and five appended papers. The thesis presents advances in sensor technology, damage identification algorithms, Bridge Weigh-In-Motion systems, and other techniques used in bridge monitoring. Four case studies are presented. In the first paper, a fully operational Bridge Weigh-In-Motion system is developed and deployed in a steel railway bridge. The gathered data was studied to obtain a characterization of the site specific traffic. In the second paper, the seasonal variability of a ballasted railway bridge is studied and characterized in its natural variability. In the third, the non-linear characteristic of a ballasted railway bridge is studied and described stochastically. In the fourth, a novel damage detection algorithm based in Bridge Weigh-In-Motion data and machine learning algorithms is presented and tested on a numerical experiment. In the fifth, a bridge and traffic monitoring system is implemented in a suspension bridge to study the cause of unexpected wear in the bridge bearings. Some of the major scientific contributions of this work are: 1) the development of a B-WIM for railway traffic capable of estimating the load on individual axles; 2) the characterization of in-situ measured railway traffic in Stockholm, with axle weights and train configuration; 3) the quantification of a hitherto unreported environmental behaviour in ballasted bridges and possible mechanisms for its explanation (this behaviour was shown to be of great importance for monitoring of bridges located in colder climate) 4) the statistical quantification of the nonlinearities of a railway bridge and its yearly variations and 5) the integration of B-WIM data into damage detection techniques. / <p>QC 20140910</p>
265

Návrh železničního rámového mostu / Design of a railway frame bridge

Findura, David January 2018 (has links)
This thesis deals with a design of a two-track railway frame bridge over a valley. Out of three proposed variants was chosen the variant number 1 - prestressed frame construction with variable beam section. According to actual EN standards the construction was designed and assessed to the serviceability limit state and the ultimate limit state.
266

Rekonstrukce mostu / Reconstruction of the road bridge

Laczko, Zoltán January 2012 (has links)
The subject of this thesis is to design a new slab structure instead of the steel concrete slab. The structure of the new load bearing structure is post-stressed cast-in-situ slab with continuous slab structure consisting of three spans. The slab is pre-stressed by monostrands. The load bearing structure is evaluated for first and second limit state too. The construction is modeled in software named Scia Engineer 2011.
267

Silniční most / The road bridge

Doležal, Martin January 2013 (has links)
This master' thesis deal with the desiggning of steel bearing structure of road bridge with span of 48,5m with lower bridge deck, which cross local road over the river Thaya in the town Znojmo. Three variants have been designed of arched bridge. The most economical variant was prepared in detail and wascarried out static assessment of individual elements and selected details. In detail solved variant is the bridge with free staing arches and lower bredge deck with composite crosspiece. The span of bridge is 48,5m, width of bridge is 11,5meters, free width of main trafic area 6,5m. Camber of bridge 8,0m
268

Obloukový most přes dálnici / Arch bridge over a highway

Pěkník, Robin January 2015 (has links)
The subject of this master's thesis is design of road bridge over highway D1 by the city Přerov. From the three proposed solutions has been chosen bridge with self-anchored arched structure which is good for deep notch. The concrete bridge was designed and assessed according to current Eurocodes. The thesis includes detailed structural analysis, drawings and visualization of the bridge. The analysis was performed using software Scia Engineer including time dependent analysis (TDA). Assessment of structure was made in Excel or by hand.
269

Study and Application of Modern Bridge Monitoring Techniques

González, Ignacio January 2011 (has links)
The field of monitoring is one of rapid development. Advances in sensor technologies, in data communication paradigms and data processing algorithms all influence the possibilities of Structural Health Monitoring, damage detection, traffic monitoring and other implementations of monitoring systems. Bridges are a very critical part of a country’s infrastructure, they are expensive to build and maintain, and many uncertainties surround important factors determining the serviceability and deterioration of bridges. As such, bridges are good candidates for monitoring. Monitoring can extend the service life and avoid or postpone replacement, repair or strengthening work. Many bridges constitute a bottleneck in the transport network they serve with few or no alternative routes. The amount of resources saved, both to the owner and the users, by reducing the amount of non-operational time can easily justify the extra investment in monitoring. This thesis consists of an extended summary and three appended papers. The thesis presents advances in sensor technology, damage identification algorithms and Bridge Weigh-In-Motion techniques. Two case studies are carried out. In the first a bridge and traffic monitoring system is implemented in a highway suspension bridge to study the cause of unexpected wear in the bridge bearings. In the second a fully operational Bridge Weigh-In-Motion system is developed and deployed in a steel railway bridge. The gathered data was studied to obtain a characterization of the site specific traffic. / QC 20111122
270

Silniční most na komunikaci III/0462 přes dálnici D46 / Road bridge on road III/0462 over highway D46

Vystavěl, Vojtěch January 2022 (has links)
This thesis deals with design of III/0462 road overpass over D46 highway near Brodek u Prostějova. There are 2 preliminary variants. First variant is a right bridge, whose main beams are tied archs. Second variant is a skew bridge with truss superstructure. In case of second variant there are three subvariants differing with truss design. Design and calculation is done according to valid standarts and other regulations for designing bridges.

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