One of the most common types of bridges in the world is a truss bridge. It uses triangles, which are very stable shapes, to create frameworks that can distribute the load through the bridge, also known as trusses. The trusses are also able to increase the overall strength of the bridge and protect the deck from warping. Examples of truss bridges include the Warren, the Pratt and the K-Truss designs.
The most common bridge design for real and model bridges is the Warren design. It was patented by James Warren, and uses equilateral triangles to support the load. While it is very effective when carrying a heavy spread-out load, it has been found that Warren bridges are not ideal for handling a localized force because its design is not optimized
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We wanted this project to both meet the criteria, but also to be practical to make, which we believed did not suit the arch bridge. As well as this, arch bridges are usually much heavier than truss bridges, which means that it would have been much harder to meet the weight criteria that went along with this project. When our group decided to further consider the arch bridges, we ended up narrowing down on three, the Warren Truss, Pratt Truss and K-Truss. We immediately decided not to do the k-truss as it was far too complex for us to do with our time constraints and limited experience. To narrow it down to the Pratt Truss, we decided to compare the efficiency of how those two bridges related specifically to our situation. During our research, we found that the Pratt Truss was better at coping with centralized loads, which made it much better suited to our project. As well as this, the Pratt Truss had been described by many websites as an ideal model for a popsicle stick bridge. With this information, our group finalized our …show more content…
We learned about three types of bridges- the Pratt, Warren and K-Truss, as well as each of their advantages and disadvantages. We also learned about arch bridges in a general sense and their advantages and disadvantages. We also researched substructures and superstructures, and how they played into bridge design. From our research we effectively narrowed down an efficient design for our bridge that we knew would meet the requirements for the project. In a broader sense, we learned a lot about the careful planning and calculations that go into making a large construction project such as this one. We will carry this knowledge into other similar projects in our future, knowing how diligent we should be in order to successfully create construction
“It was designed with a twenty-two foot roadway and one five-foot sidewalk” (Silver). The silver bridge is a very long bridge. “An eye-bar is a long steel plate having large circular ends with an "eye" or hole through which a pin is used to connect to other eyebars (to make a chain) or to other parts of the bridge.” according to Richard Fields. The whole bridge was built using the eye-bar suspension.
The Bailey Island Bridge is located in Harpswell, Maine on Route 24. Before the making of the bridge, the fishermen that lived on Bailey’s Island wanted a bridge that connected their island to Orr’s Island. The town of Harpsweell made and voted on their decisions in the weekly town meetings (“Bailey”). The project was stalled because of some of the mainlanders in the town, but it was brought back up for discussion in 1912. They first agreed on a “road” which would connect the two islands and would be constructed with timber. This was to cost $3,000. The cost quickly reached $25,000 at a later town meting because they decided to build the bridge with stone and concrete instead. Once the legislature decided to pass a bill stating that it would fun state’s highway and bridge projects, they decided to move forward with the project (Hansen, 36).
At the time of its construction in 1929, the Ambassador Bridge was the largest spanned suspension bridge at 564 meters until the George Washington Bridge was built. It was an engineering masterpiece at the time. The total bridge length is 2,286 meters and rises to 118 meters above the river. Suspension cables support the main span of the Ambassador Bridge and the main pillars under the bridge are supported by steel in a cantilever truss structure. In total, the McClintic-Marshall masterpiece is comprised of 21,000 tons of steel. The immense socio-economical impact that the Ambassador Bridge has on transportation and trade is imperative for daily interaction between the Un...
The Golden Gate bridge, standing as an icon of roadway innovations, took multiple engineers years to design and complete. They could not just simply build an ordinary bridge. They had to take into consideration the physics behind it, as well as, what kind of effect the environment would have upon the bridge. The bridge sits along one of the most active fault lines in the world, so engineers had to make sure their bridge could withstand a little movement. Today the Golden Gate bridge still stands tried and true, as does many other innovations that 20th century engineers came up with.
The area of where the bridge was to cross the Ohio River was said to be one of the hardest places to build but came with some advantages. The section of the river had a solid rock base for the supporting pier to be built on. Since the engineers knew they could build a pier that would not settle they decided on a continuous bridge design. This design type distributes the weight so the steel trusses could be smaller and riveted together. This alone saved an estimates twenty percent of steel that was originally thought to be need to make the bridge cutting down the cost. The two continuous trusses span a collective 1,550 feet across the water. With addition of the north and south approach viaducts, for trains to go under the bridge, the superstructure’s total length is 3,463 feet. The bridge was made to hold two sets of tracks making the width 38 feet and 9 inches. The design called for 27,000 cubic yards of concrete and 13,200 tons of steel with some members being four foot square beams that span a distance of seventy feet. The design was the first step in a long process that would take several years to
Following the collapse of the I-35 Bridge, other bridges in the country, with similar construction designs, were scrutinized. According to federal statistics, more than 70,000 of the 607,363 or roughly 12 percent of the bridges in the United States are classified as “structurally deficient.”
According to Suspension bridges: Concepts and various innovative techniques of structural evaluation, “During the past 200 years, suspension bridges have been at the forefront in all aspects of structural engineering” (“Suspension”). This statement shows that suspension bridges have been used for over 200 years, and that people are still using them today because they are structurally better bridges. This paper shows four arguments on the advantages of suspension bridges, and why you should use one when building a bridge. When deciding on building a suspension bridge, it has many advantages such as; its lightness, ability to span over a long distance, easy construction, cost effective, easy to maintain, less risk
One of the great engineering feats when building this bridge was the use of steel. Despite its maximum height of 343m span of 2.46km, 280m above the valley floor, the bridge is actually quite light. 242,000 tonnes seems like a lot but without the use of steel on the structure, this bridge would have been more than twice as heavy. Steel is a much stronger material than concrete, so can support more weight with less mass. The actual road deck, which is comprised almost entirely of steel, only weighs 36,000 tonnes. The other 206,000 tonnes comes primarily from the massive pylons, which are m...
The first and most challenging problem associated with building the Mackinac Bridge arrived long before the bridge was even designed. Financing such an enormous project was no easy feat. In 1928, the idea of connecting the upper and lower peninsulas was proposed to Congress for the first time (Brown 4). At the time, the suspected bridge project was very much under government scrutiny and control. In fact, the initial boost in interest in pursuing the construction of a bridge came about due to the depression. The Public Works Administration (PWA) had been created under President Franklin D. Roosevelt’s New Deal economic plan which would fund certain construction projects with th...
The Tacoma Narrows Bridge is perhaps the most notorious failure in the world of engineering. It collapsed on November 7, 1940 just months after its opening on July 1, 1940. It was designed by Leon Moisseiff and at its time it was the third largest suspension bridge in the world with a center span of over half a mile long. The bridge was very narrow and sleek giving it a look of grace, but this design made it very flexible in the wind. Nicknamed the "Galloping Gertie," because of its undulating behavior, the Tacoma Narrows Bridge drew the attention of motorists seeking a cheap thrill. Drivers felt that they were driving on a roller coaster, as they would disappear from sight in the trough of the wave. On the last day of the bridge's existence it gave fair warning that its destruction was eminent. Not only did it oscillate up and down, but twisted side to side in a cork screw motion. After hours of this violent motion with wind speeds reaching forty and fifty miles per hour, the bridge collapsed. With such a catastrophic failure, many people ask why such an apparently well thought out plan could have failed so badly?(This rhetorical question clearly sets up a position of inquiry-which iniates all research.) The reason for the collapse of the Tacoma Narrows Bridge is still controversial, but three theories reveal the basis of an engineering explanation. (Jason then directly asserts what he found to be a possible answer to his question.)
This memo is a failure analysis report on the Tacoma Narrows bridge. The bridge collapsed on November 7th, 1940 just over four months after it was opened to the public on July 1st, 1940(Green, 2006). The only casualties(good word??) from the bridge collapse were reporter Leonard Coatsworth’s car and dog. The bridge’s design and failure will be discussed, as well as new suspension bridge design methods.
The reason I picked the design I did was because it seemed like a solid and traditional style of bridge. The bridge mirrored a Warren Truss bridge which is general, but efficient at distributing the weight across the bridge. I am relatively inexperienced at building, so the Warren Truss seemed like the best idea since it is both simple and effective.
In her essay,”Importance of the Golden Gate Bridge,” Stephanie Stiavetti suggest that “It maintained this point of pride for nearly 25 years until the Verrazano- Narrows Bridge was built in New York in 1964. Today, this historic San Francisco landmark holds its place as the second largest suspension bridge in the country, behind Verrazano Narrows.” Back then, experts thought that it would be impossible to build a bridge across the tides and currents in that area because strong currents and tides would make construction extremely difficult and dangerous. The water is over 500 feet deep in the center of the channel, and along with the area's strong winds and thick fog, the idea of building a bridge there seemed nearly impossible. Despite all of the problems of building a bridge across the Golden Gate, Joseph Strauss was named as lead engineer for the project. Construction began January 5, 1933, and in the end cost more than $35 million to
Bridge efficiency is important as it helps reduce cost of building while maximizing the strength of the bridge. Many things can influence the bridge’s strength and weight, but the two main things that can cause a bridge to be a failure or success is the design of the bridge and construction of its joints. In order to build a potent balsa truss bridge, it is crucial to know how the layout of members and style of gluing can help increase or decrease strength.