.0 Superstructure
The superstructure elements will be defined as those inclusive to the portion of the bridge structure, which forms the horizontal span, all components above the bearings. The following will delineate the major superstructure elements, and investigate accelerated bridge construction techniques and technologies, which can be applied. The major structural components, which will be examined in the following section, will include girders, stay-in-place deck forms, deck panels and modular superstructure construction systems.
1.1 Girders
Bridge girders for the purpose of the following examination will be divided into two (2) sections: steel girders and precast - prestressed concrete girders. The use of shop fabricated girders
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Department of Transportation, Federal Highway Administration Accelerated bridge construction manual “Adjacent butted precast girder systems such as double tees and deck bulb tees create opportunities for ABC. These girders function as both the beam and the deck, thereby eliminating the need for deck placement in the field.” (U.S Department of Transportation, 2011)
1.2 Stay-in-Place Deck Forms
A significant portion of the bridge construction schedule can be attributed to the forming and stripping of concrete deck forms. Stay-in-place concrete deck forms are used to eliminate the need to strip forms after the concrete deck has been cast and cured. The two (2), most common forms of stay-in-place deck forms are corrugated steel sheets and partial depth precast concrete panels. (U.S Department of Transportation, 2011)
1.2.1 Corrugated Steel Stay-in-Place Deck Forms
Galvanized corrugated steel sheets are placed above the bridge girders from flange to flange to act as a stay-in-place deck form. Furthermore, these steel deck forms act to provide support for the reinforcing steel in the deck slab as well as supporting the weight of weight concrete during the construction process. Corrugated steel stay-in-place deck forms remain in place for the live of the structure thus serving to eliminate the need of form stripping and the associated schedule time. Corrugated Steel Stay-in-Place Deck Forms can be used on steel and precast – prestressed
Would you rather be a hunter who gets hunted or a marshal who must face his dark past? In the story The Most Dangerous Game, by Richard Connell, a world-renowned hunter is trapped on an isolated island and must fight for his life, along the way learning that being the hunted does make you feel one emotion; fear. In the film High Noon, written by Carl Foreman, a newly wedded marshal must make the decision to either fight his past or run away with his future. In both High Noon and The Most Dangerous Game, the conflicts are similar; however, there are many differences between the theme and setting, which affects the plot for both stories
Initially, suspension bridges before 1940 were made of piers, towers, wires, anchorages, and roadways. Piers were the main foundation for the suspension bridges. There usually were two of them, which were made out of cement and were entrenched in ground underneath the body of water that the bridge was spanned across. Towers were built on top of the piers to provide a means of connection for the roadways and wires. Wires were connected to the towers, roadways, and anchorages to provide tension support for the weight of the bridge. The anchorages were large cement platforms that were planted into the ground on either side of the land so that the wires could be connected to it. Lastly, the roadways were the main point of the suspension bridge. They usually were wide enough to provide four lanes of traffic and stretched from one side of the bridge to the other. This was the basic design of the suspension bridges
The final primary component of a suspension bridge is the deck, or the roadway upon which cars drive and pedestrians walk. The deck is built from massive pieces of steel-reinforced concrete hoisted into the air and laid into place upon the bridge. Deck pieces are connected with bolts and rivets, then suspension cables connect each section of deck to the main
Tom Robinson’s fate was decided; the jury voted he was guilty of all charges of rape against him, even though his lawyer, Atticus Finch, defended him and presented sufficient evidence that could have proved Tom Robinson’s innocence. When Robinson came to the stand, Mr. Finch attempted to persuade the jury with Robinson’s perspective while Mr. Gilmer, Mayella Ewell’s lawyer, thoroughly cross-examined Robinson to attempt to make him stumble and incriminate himself when he answered questions and retold parts of his story. Mr. Finch questioned Robinson first. He asked Robinson numerous questions that were meant to prove his innocence and prove Robinson had nothing to lie about. Mr. Finch began asking questions to give those present in the courthouse background on Robinson’s
Since the early days, the men try overcome environmental challenges and, in this process, ends up creating amazing masterpieces of engineering. Among this works, the bridges appears as the clearest representatives of how the mankind could adapt to Earth’s contours. If the shape of landscape can’t be changed, the bridges are the solution to link two places and allows the connection of the traffic to improve aspects such as the communication and the trade. Depending to the need, to the sources and to the environment, the bridge can be constructed in a specific configuration. There are five main sorts of bridges configurations. First, there is the simplest bridge, the beam bridge. Second, the arch bridge, one of the oldest kind. There are the truss, composed of set of trellises. Lastly, there are the cable-stayed and
Prior of this time, most bridge design were based on trusses, arches, and cantilevers to support heavy freight trains. Automobiles were obviously much lighter. Suspension bridge design had been envolving into producing bridges of maximum grace, lightness and flexibility which actually was more suited for carrying lighter cars and not heavier train. Unfortunately, engineers did not fully understand the response of the suspension bridge design to these poorly understand forces. The second reson was due to the excitation of torsional mode. The Tacoma Narrows Bridge was built with shallow plate girders instead of the deep stiffening trusses of railway bridges, in which trusses allowed wind to pass through but plate girders, on the other hand, present an obstacle to the wind. As a result of its design, it was proved that the bridge was too light and unstable. And causing alloping Gertieaction which were driven by the wind were being experienced by the bridge.
When the bridge was inspected at check-in, many of the officials said that the bottom supports of the bridge were
It is shaped in a way to transfer weight to the towers and anchors with its tension (O'Connor, 1971, p. 372). Cables are made of high strength wires spirally bound to form a rope (O'Connor, 1971, p. 372). Vertical cable suspenders that are fastened to the main cables hang the actual roadway. Stiffening girders and trusses are along the side of the bridge to distribute concentrated loads and help to keep the motion of the bridge at a minimum (Troitsky, 1994, p115).
The bridge has a very well designed ‘sustainability’ concept, relying on upcycled materials to complete the bridge. These upcycled materials consist of the wood, the fishing net, the oil barrels and the plastic shielding for the barrels. These materials can be used for functional roles in the design, such as platforms, floatation, safety lines across hand rails, and so on. The bridge’s sustainability concept can be further supported by the ease of replacing materials, and not throwing them in the bin. The materials such as wood, plastic and pieces of metallic bolts and nuts can be recycled and reused for other purposed such as furniture, storage or completely recycled back into a molten form for the metallic objects.
Design Elements: While building this bridge, the first design element, was the deck design. We took around one horizontal length of vertical popsicle sticks and lined them side by side, and repeated. Later we connected them together with a horizontal popsicle stick. I then took two lines and placed them ontop of eachother to create a flat surface. This way it will carry a lot of weight, and it will also run smoothly. After this I created trusses to put on the side, so that the weight would be evenly distributed amongst the bridge, instead of all the weight on one part. This would help stop the bridge from immediately bending once weights were put into the bucket. To make the trusses I had to take popsicle sticks and glue them into a triangle shape, and then glue them together from the bottom. This way they wouldn’t break apart. I then doubled them up so that it would be able to sustain more weight. Under the bridge I placed a lot of beams, so that the bridge would hold together from the bottom, instead of immediately bending once I placed a weight. I made the beam from gluing
The construction process of our model suspension bridge went smoothly. We designed a blueprint that showed our bridge in a life size scale. The materials used to build our bridge included two 18 inch tall two by fours for the anchoring towers of the suspension bridge, one 30
There are only a very few limitations in the use of plate girders. Compared with trusses they are heavier, more difficult to transport and have larger wind resistance. The provision of openings for services is also more difficult. The low torsional stiffness of plate girders makes them difficult to use in bridges having small plan radius. Plate girders can sometimes pose problems during erection because of concern for the stability of compression
In 2004, Moose Creek Bridge on highway 101, was the first Canadian bridge project that was fully built by prefabricated elements for both substructure and superstructure. The bridge is a single span 22 m long integral abutment bridge with overall deck with of 14.64 m. Prefabricated restressed slab-on-girder T-shaped beams was used for construction of superstructure (Canadian Civil engineering 2011 Accelerated Bridge Construction).
Because of advancements in today’s technology in construction field, many types of bridges are being constructed depending on the requirement and their suitability for the situations.
While most of my internship rotations are located in Los Angeles, California I will need to travel twice during my 10-month internship. In late June of 2017, I will be traveling to Greely, Colorado for a 3-day orientation at the University of Northern Colorado. I estimate about 1,000 in expenses. Furthermore, I will be traveling to Las Vegas, Nevada for my clinical rotation in late August to late October 2017. An estimate about an additional 5,200 in living and travel expenses for those 8 weeks. Unfortunately, my school does not provide scholarships or financial assistance/loans for their interns. My desire to pursue a career as a dietitian stems from my passion for disease prevention and control in children and the elderly. My curiosity began