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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.
71

Isolerande balkonginfästningar : Thermally-insulated balconies

Kulasin, Aid January 2009 (has links)
In this work a study has been performed to show the different kinds of insulated balcony connections exists on the market. In the work there is also a short description of thermal bridges concerning balconies. A description of older solutions for balcony connections is given as well as a calculation of the difference in energy costs for a insulated balcony connection compared to the standard connection. The work includes a short description of the different products. After that there is a short information about their insulation properties, durability, acoustic performance, assembly, computer programme and a short analyses for each product.
72

HURRICANE INDUCED WAVE AND SURGE FORCES ON BRIDGE DECKS

McPherson, Ronald L. 16 January 2010 (has links)
The damaging effects of hurricane landfall on US coastal bridges have been studied using physical model testing. Hurricane bridge damage and failure susceptibility has become very evident, especially during hurricane seasons 2004 and 2005 in the Gulf of Mexico. The combination of storm surge and high waves caused by a hurricane can produce substantial loads on bridge decks leading to complete bridge failure. Several theoretical methods have been developed to estimate these forces but have not been tested in a laboratory setting for a typical bridge section. Experiments were done using a large-scale 3-D wave basin located at the Haynes Coastal Engineering Laboratory at Texas A&M University to provide estimates of the horizontal and vertical forces for several conditions to compare with the forces predicted with the existing models. The wave force results show no strong correlation between the actual force measured and the predicted force of existing theoretical methods. A new method is derived from the existing theoretical methods. This model shows a strong correlation with both the measured horizontal and vertical forces.
73

Calculation of Extreme Wave Loads on Coastal Highway Bridges

Meng, Bo 14 January 2010 (has links)
Coastal bridges are exposed to severe wave, current and wind forces during a hurricane. Most coastal bridges are not designed to resist wave loads in such extreme situations, and there are no existing analytical methods to calculate wave loads on coastal highway bridges. This study focuses on developing a new scheme to estimate the extreme wave loads on bridges for designing purpose. In order to do this, a 2D wave velocity potential model (2D Model) is set up for the deterministic analysis of wave force on bridge decks. 2D Model is a linear wave model, which has the capability of calculating wave velocity potential components in time domain based on wave parameters such as wave height, wave period and water depth, and complex structural geometries. 2D Model has Laplace equation as general equation. The free surface boundary, incoming and outgoing wave boundary conditions are linearized, decomposed first, and then solved by the finite difference method. Maximum wave forces results calculated by the linear 2D Model are compared with results from CFD software Flow3D that is using Navier Stokes theory up to the 5th order; and 2D Model is validated by comparing results with experiment data. A case study is conducted for calculating extreme wave forces on I-10 Bridge across Escambia Bay, Florida during Hurricane Ivan in September 2004.SWAN model is adapted to investigate the parameters of wave heights and wave periods around bridge sites. SWAN model has the capability of predicting or hindcasting significant wave heights and wave periods as long as the domain and input parameters are given. The predicted significant wave heights are compared with measurements by Buoy Station 42039 and 42040 nearest to Escambia Bay. A new prediction equation of maximum uplift wave forces on bridge decks is developed in terms of wave height, wave period, water depth, bridge width, water clearance and over top water load. To develop the equations, the relationship is investigated between maximum uplift wave forces and wave parameters, water clearance, green water effects and bridge width. 2D Model is used for up to 1886 cases with difference parameters. Flow3D model is adopted to determine coefficients of water clearance and green water effects, which cannot be calculated by 2D Model.
74

Computer data base assessment of masonry bridges

Sihwa, L. January 1987 (has links)
This thesis is concerned about the development of computer data base management system for the assessment of masonry bridges. The various techniques of assessment and remedial measures of masonry bridges are outlined, their shortcomings described. A justification for an alternative method of assessment is given. A review of computer data base management systems is carried out. The reasons for adopting data base management systems is given as well as the reasons for choosing a particular type of data base management system. The common faults associated with masonry structures are described and the problems of identifying these faults are described. The part played by the individual components of a masonry arch bridge is given and the significance of faults on the individual components of the structure is described. A detailed description of the type, in general of the data base system chosen is given followed by a detailed description of a special case of the type chosen, which is the system that was used for the project. A description of how the system was developed is given followed by the way the system operates. A detailed description of how the system can be used is then put forward and the problems associated with the development of the system are outlined. Finally, a description of the implications of the system to the practising engineer is given.
75

Truck Size and Weight Analysis for the Development of a European Bridge Formula

Moshiri, Maryam January 2011 (has links)
The research analyzes the bridge load stress effects resulting from international bridge formulae and truck size and weight regulations in Europe. This is done with a view to identifying issues that may need to be considered in the development of a European Bridge Formula (EUBF) conforming to European Directive truck configurations for the regulation of truck size and weight limits associated with international travel between European Union (EU) member states. The level of efficiency of bridge formulae vary depending on the design criteria used in the development of the formula, the compatibility to the jurisdiction’s infrastructure and truck fleet characteristics, and the method of implementation as part of the regulation and by operators in the trucking industry. The EUBF should limit imposed critical bending moment and shear stresses on single and continuous span bridges of varying lengths (5, 20, and 50 metres) in accordance to design live loads specified in the Eurocode. The analysis of bridge load effects imposed by European Directive truck configurations in this research, provide the basis for the development of a EUBF.
76

Anchored Log Decks

Murison, Evangeline Rivera 10 April 2014 (has links)
To improve the performance of the conventional nail laminated bridge deck, three generations of innovative decks have been developed during the last three decades: (a) the stress laminated wood deck, (b) the stressed log bridge, and (c) the grout laminated wood deck. The grout laminated wood deck, the most recent wood deck, consists of trimmed logs interconnected with internal grout cylinders, in compression or tension. Previous research has shown that the grout cylinders have superior load distribution characteristics, but the cost of trimming the treated logs was found to be relatively high. Recently, research has been conducted to develop the next generation of the bridge wood decks, called the anchored log decks. The anchored log deck, meant for use as decking of steel girder bridges, consists of untrimmed discarded utility timber poles which have been treated with preservatives. The logs are held together by means of unstressed transverse proprietary Cintec anchors. The anchors consist of stainless steel rods encased in grout cylinders. Panels, each comprising of 5 to 6 logs, are preassembled to fit on a flatbed trailer for shipping. The smooth wearing surface over the log deck is provided by longitudinal sawn timber planks, with high-density foam filling the gap between the logs and the planks. The panels are inter-connected through inclined anchors passing through adjacent logs. At the University of Manitoba, an anchored log deck with five preassembled panels was constructed and tested to failure at several locations under both static and fatigue loads. The test results have shown that anchored log decks have the potential of being economical preassembled decks for steel girder bridges.
77

Truck Size and Weight Analysis for the Development of a European Bridge Formula

Moshiri, Maryam January 2011 (has links)
The research analyzes the bridge load stress effects resulting from international bridge formulae and truck size and weight regulations in Europe. This is done with a view to identifying issues that may need to be considered in the development of a European Bridge Formula (EUBF) conforming to European Directive truck configurations for the regulation of truck size and weight limits associated with international travel between European Union (EU) member states. The level of efficiency of bridge formulae vary depending on the design criteria used in the development of the formula, the compatibility to the jurisdiction’s infrastructure and truck fleet characteristics, and the method of implementation as part of the regulation and by operators in the trucking industry. The EUBF should limit imposed critical bending moment and shear stresses on single and continuous span bridges of varying lengths (5, 20, and 50 metres) in accordance to design live loads specified in the Eurocode. The analysis of bridge load effects imposed by European Directive truck configurations in this research, provide the basis for the development of a EUBF.
78

Development of cable elements and their applications in the analysis of cable structures

Ahmadi-Kashani, K. January 1983 (has links)
No description available.
79

Static and dynamic behaviour of cable assisted bridges

Yiu, P. K. A. January 1982 (has links)
No description available.
80

Experimental investigations and non-linear numerical analysis of skewed one-way prestressed concrete bridge decks

Cope, M. D. January 1987 (has links)
No description available.

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