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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

Parapet Load Distribution to the Bearing Pads of Prestressed Concrete Girders in a Simple Span Bridge

Austiff, Calvin 01 December 2014 (has links)
In current bridge engineering an idealized model is used to apply the parapet load to the bearing pads of a bridge. In this idealized model it is assumed that the parapet load is evenly distributed across all of the bridge bearing pads. However, this assumption is incorrect. The purpose of this study is to demonstrate that the parapet load distribution is more complicated than an evenly distributed load. Instead, this study shows that a majority of the parapet load is applied to the exterior bearing pad. This means that the real world exterior bearing pad reactions will be much larger than the reactions found using the idealized, evenly distributed model. This study utilizes the finite element program, NISA, to model and analyze a simple span bridge. The bridge used in this study was developed using a prestressed concrete girder design example from the Texas Department of Transportation. The design example specified the span length, clear roadway width, prestressed girder type, and girder spacing of the bridge. The bridge is modeled under two different loading conditions to ensure a comprehensive array of results is obtained. The two loading conditions were carefully designed to compare the idealized model, utilized by the Federal Highway Administration, to the real world parapet load distribution. The focus of this study is to determine how the parapet load distribution will affect the bearing pad reactions in a simple span bridge. The results of this study are provided in several tables depicting the bearing pad reactions obtained from the finite element models. The results of each parapet load distribution are compared to one another and percent differences are calculated between each condition. This allows for the use of a single number to define the effect the parapet load distribution has on the bearing pad reactions. A secondary focus of this study is to determine how a bearing pad's deformation, and thus its stiffness, will affect the bearing pad reactions of a simple span bridge. The results of this study are provided in several tables depicting the bearing pad reactions obtained from the finite element models. The results of each bearing pad stiffness condition are compared to one another and percent differences are calculated between each configuration. This allows for the use of a single number to define the effect of bearing pad stiffness on the parapet load distribution. This portion was completed first and the best model was chosen to be used in the main part of the study.
2

Assessment of Parapet Loads Distributed to Prestressed Concrete I-Beams in Simple Span Bridges

Siegert, Amelia Leigh 01 January 2009 (has links)
In engineering practice, there is no clear reference or guidance for the computation of the superimposed parapet load distributed to each girder of a bridge. The purpose of this study is to determine the distribution of the parapet wall weight load to prestressed concrete girders for simple span bridges. The focus is on the reactions at the bearings of simple span bridges. It was found in this study that the exterior girder takes about fifty percent of the parapet load distribution in a case with five girders. This study presents background, introduction, data, and results pertaining to this research. Care is made to fully explain all procedures and terminology for complete understanding of the topic. This study implements the finite element analysis program NISA to test simple span bridge models and collect the data of the reactions at the bearings of these models. Multiple models are created that use AASHTO Types III prestressed concrete girders. The lengths of the girders as well as the cantilever span lengths of the deck will vary. The focus of this research is to determine the distribution of the parapet weight loading on the prestressed concrete girders of simple span bridges. The results are provided in table form showing the reactions on the bridge models. The ratios of the load distribution of the exterior beams to the load distribution of the interior beams are also shown. This data provides a reference for the load distribution of the parapet wall weight to the girders.
3

The influence of windward parapets on the height of leeward snow drifts at roof steps

Goodale, Christopher Brandon January 1900 (has links)
Master of Science / Department of Architectural Engineering / Kimberly Waggle Kramer / The American Society of Civil Engineers (ASCE) has developed standards for the design of snow loads that occur on buildings and structures. These standards are published in the Minimum Design Loads for Buildings and Other Structures, or ASCE 7, and are based on the findings of case studies and other scientific tests. However, design guidance on the possible reduction of leeward snow drifts at the junction of a roof parapet and a moderately sized roof step is limited and not specifically addressed in the ASCE 7. Therefore, a literature review and parametric study were performed to evaluate possible leeward snow drift reduction that could occur at the junction of parapets and roof steps. Leeward drift reduction was estimated using the Fetch Modification Method, the Direct Reduction Method, and the Simplistic Reduction Method for parapets with heights of 30 in. and 48 in. with upwind snow fetch distances from 100 to 300 ft and ground snow loads from 20 to 50 psf. More drift reduction was seen with the 48 in. parapets than with the 30 in. parapets. The Fetch Modification Method and the Direct Reduction Method gave relatively similar reductions across the range of upwind fetch distances, while the Simplistic Reduction Method gave larger reductions overall. Reductions in height for the Fetch Modification Method were between 0.25 ft and 0.42 ft, while the Direction Reduction Method returned 0.08 to 0.63 ft and the Simplistic Reduction Method returned 1.61 to 3.09 ft. Due to the large magnitude of reduction estimated by the Simplistic Reduction Method, the method was considered unconservative. From the results of the Fetch Modification Method and Direct Reduction Method, it could be suggested that parapets 30 in. or 48 in. tall could only provide a small amount of leeward drift reduction, roughly 7% to 8% of the original leeward drift height. Further research should be done to expand the heights of parapets examined and to incorporate testing and full scale observations to verify the reduction of the leeward drift.
4

Simulation of vehicle crash into bridge parapet using Abaqus/Explicit

Ogmaia, Daly, Tasel, Sebastian Elias Tasel January 2015 (has links)
Safety is an important aspect when designing bridges and roads. One aspect among others to consider is the road restraint systems. The focus of this study was centered to safety barriers which are the vehicle parapets/guardrails. The parapet must meet certain requirements specified in European Standard in order to obtain a CE-marking, indicating the acceptance of use. Full-scale test must be performed for a proposed parapet to evaluate the performance. Often several full-scale tests are performed in order to achieve CE-marking, making it an expensive process. The primary objective of this master thesis was to investigate if Abaqus/Explicit could be used as the finite element software for simulation of crashes. Secondary objective was to investigate how well a performed full-scale crash could be simulated in Abaqus/Explicit. A full-scale test was conducted and the parapet installation and vehicle used was modeled. Same conditions as in the full-scale were used in the simulation. The results indicated that it is possible to simulate the full-scale crash using Abaqus/Explicit. However, the behavior of the full-scale test was not completely captured. The maximum dynamic and permanent horizontal deflection of the tabular thrie beam in the full-scale test was 582 mm and 515 mm, corresponding value from the simulation was 703 mm and 643 mm. The conclusion from the results is that Abaqus/Explicit is a suitable finite element software for simulating crashes. The differences between the full-scale test and the simulations in this master thesis were due to the simplifications and assumptions used when modeling the parapet, bridge deck and the vehicle. The overall global behavior of the full-scale test was not captured, however the simulation results were not far from the full-scale test even though rough simplifications and assumptions were used in the modeling. We believe that with more care to details in modeling, it should be possible to have better convergence between simulation and the full-scale test.
5

Analysis of Uncontrolled Concrete Bridge Parapet Cracking

Bazzo, Jeffrey D. 07 November 2012 (has links)
No description available.
6

The Evaluation on the Effectiveness of Hydrodemolition and Polyaspartic Sealing for Bridge Parapet Wall Protection

Mullins, Sarah K. January 2018 (has links)
No description available.
7

Implementation and Field Testing of Improved Bridge Parapet Designs

Kalabon, Amy Elizabeth 30 May 2014 (has links)
No description available.
8

Mateřská škola / Nursery School

Václavek, Jaroslav January 2014 (has links)
The topic of my diploma thesis is „A Nursery School with a Special Classroom“. It is two-storey building, partly cellared with a single-covering roof with parapets. As for supporting system there were used HELUZ two-way walls.The ceiling structure is made of Filigrán, a prefa-monolithic plates. The building is situated southward on slightly-sloping building plot. The whole construction and materials are in accordance with applicable standards of ČSN.
9

Veřejná knihovna s kavárnou / Public library with cafeteria

Vlach, Ondřej January 2016 (has links)
The aim of this diploma thesis is to create a detailed design of a public library with cafeteria. The building is situated in the developing city area of Jihlava in the cadastral area of Horní Kosov. It has four storeys above ground and no basement floor. The 4th floor has a smaller net floor area than the rest floors. The building is designed also for disabled people. The expected number of employees is 18 and the number of visitors is 150 in a daily average. An entrance to the property is on the Vrchlického street. There is a parking lot in front of the building with a total capacity of 50 parking spaces including three parking spaces for disabled. The cafeteria and its facilities are situated in the ground floor of the building. Browsing area is situated in the second and third floor. The type of the structure is a frame structure with infill walls made of aerated concrete. The building has a double-skin facade. The cladding of the facade is made of fibre-cement boards. There is a curtain wall designed at some sections of the facade. The building has a warm flat roof with a parapet wall and interior roof drains.
10

Hotel / Hotel

Řehoř, David January 2015 (has links)
The objective of this thesis is to draw up the design documentation for the construction of a hotel. The hotel is situated on the edge of the golf resort Kaskáda near to Jinačovice. It’s a brick building with two above – ground floors and one underground. There is the staircase in the building that creates protected escape route. The perimeter wall is designed of ceramic bricks Porotherm T Profi. They are filled – in by mineral wool. The hotel is divided into three dilatational parts. There are 35 guest rooms in the hotel; two of them are barrier – free, in total 63 beds. In the ground floor there are entrance, reception, restaurant, bar, kitchen with the background. In the basement there are technical equipment, a fitness room, a wellness, changing rooms, washrooms and a bar. The roof of the hotel is flat. There is the terrace accessible from the apartments in the second floor above the restaurant.

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