The Change Between Suspension Bridges Before 1940 and Suspension Bridges Today

In the small town of Waco, Texas who would have thought it was once well known for the structure of a bridge, the Waco Suspension Bridge to be exact. Up until 1870, the Brazos River was just a simple river that had no special meaning to it. The land around it was empty, occasionally you would find cattlemen pushing their cattle across stream, but that was only because you could not find one bridge that spanned the eight hundred miles of river flowing through Central Texas. This caused a serious transportation issue for merchants and travelers. It became clear that a better means of crossing the river was necessary.

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

The Clifton Suspension Bridge is located in Bristol England, and spans the beautiful Avon gorge. This bridge has become the symbol of Bristol much like the Eiffel tower has of Paris, and the Opera house has of Sydney. The story of the Clifton Suspension Bridge began in 1754 with the dream of a Bristol wine merchant who donated his life savings to build a bridge over the gorge. To decide on a suitable design for the bridge a competition was held. Thomas Telford, the leading civil architect of the time was the judge. Mr. Telford attempted to submit his own design; however the decision to declare himself the winner was overruled and a second competition was held. This time, contrary to the recommendation of

My suspension bridge will be the Clifton Suspension Bridge, this bridges is located at Bristol, England. This bridge was first opened in 1864,it is 212 metres long and has a width of 9.4 metres this is why this bridge is so well acclaimed due to it age and its size. This bridge crosses the River Avon. This bridge was originally meant to be made in 1831 but this was stopped by the Bristol riots, after the Bristol riots the design was charged slightly because of new technologies to strengthen the bridge. Avon Gorge came up with the idea to make the bridge in 1753 when he came up with an idea to make a bridge over the Bristol river, made from stone and which was delayed because of enhances in technology. deck is suspended by 81 matching

The truss design, which is a variant of a triangle, creates both a very rigid structure and one that transfers the load from a single point to a considerably wider area. After being used for 2000 years of architectural use, the arch continues to feature prominently in bridge designs. Its semicircular structure elegantly distributes compression through its entire form and diverts weight onto its two abutments, which are the components of the bridge that directly take on the pressure being exerted onto the bridge. The tensional forces in arch bridges are virtually negligible. That is because the natural curve of the arch and its ability to dissipate the force outward greatly reduces the effects of tension on the underside of the arch. The greater the degree of curvature, the greater the effects of tension on the underside of the bridge. If you build a big enough arch, the tension will eventually overtake the support of the bridges natural structure. While there is a fair amount in variety in arch bridge construction, the basic structure of every arch bridge is the same. For example there is Roman, Baroque and Renaissance which are all architecturally different they all have the same basic structure. It is the individual arch itself gives its namesake bridge its strength. An arch made of stone doesn’t need a mortar. In fact the ancient Romans built arch bridges and aqueducts that are still standing today and are made

Bridges are a vital part of people’s everyday life and without them people would not be able to do nearly as much as is possible today. The weather in the outer banks of North Carolina is very rough and can be very detrimental to the various structures on them. When hurricanes come near North Carolina the outer banks are hit the worst. Bridges on the outer banks keep being destroyed by weather and so the people there have to think about the cost, the effectiveness, and the need between a strong expensive bridge that will be able to handle rough weather or a cheap quick to build bridges that may fall with any extreme weather.

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

Truss bridges have a lot of history and appear really early in the building of the modern bridge age. They

The Pratt truss bridge was originally founded by Caleb and Thomas Pratt in 1844. It is mainly used to carry trains. The biggest advantage of this bridge was its low costs for construction and the materials to construct a truss bridge are minimal. It also use materials that is cheaper and light in weight. We can easily identify a pratt truss by detecting its diagonal members, which (excluding for the very end ones) all slant down and in toward the center of the span. The pratt truss was designed by applying few laws that related to the mechanics of materials concept. The bridge is mainly built using steel girders to support the construction of the structure. The below part of bridge weight is high so, it need an enough support to prevent from

The Tacoma Narrows Bridge was designed for a wind speed of 100 miles per hour and a static wind pressure of 30 pounds-force per square foot but unfortunately the bridge failed at a wind speed of less than half and a static wind pressure of one-sixth (Delatte, 2009). This phenomenon raises a big question mark on how this is possible. At first, resonance was suspected to be the main cause of the bridge failure (The New York Times, 1940). After some proper research and thorough investigations by engineers, they came up with several theories on how did the bridge collapse. The primary cause of the collapse lies in the general proportions of the bridge and the type of stiffening girders and floor. The ratio of the width of the bridge to the length of the main span was so much smaller and the vertical stiffness was so much less than those of previously constructed bridges that

As a replacement for the ferry system in place to venture across the Tacoma Narrows, the 2,800 feet long bridge was created. However, in an attempt to make the bridge more cost-effective, it was built with an unusual design for a suspension bridge- an extremely thin frame of only thirty-nine feet. This created sufficient space for only two lanes on the roadway. Originally, the bridge was supposed to be made more sturdy through the addition of trusses, yet there were inadequate funds. As a result, a cheaper alternative- 8-foot girders- were added on. They were included on the entire expanse of the bridge. However, there was not a sufficient stiffening effect created on the bridge by these girders. There was not enough research in existence on aerodynamic stability for suspension bridges, and wind tunneling/aerodynamic lift was thus not properly accounted

(Vasani, 2011) Many components when assembled together form a bridge structure. Basic components of a bridge are superstructure or Decking, Bearings, Substructure which again consists of Piers and Abutments, Wing walls and Returns, and Foundation.

Suspension bridges can only withstand a certain amount of weight, which means that only a certain type of traffic are able to cross a suspension bridge or it will fail. For some communities, this may limit access options to their region at large because only a certain amount of the population can cross the bridge at any given moment.

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.

Another common environmental factor that engineers are concerned with when they consider the conditions of bridges is wind loads. These are especially a hazard to cable-supported bridges because the system relies on a delicate balance of pressure that holds up the bridge, which can be easily disturbed under high winds. One example of this is the Tacoma bridge failure in Washington state in 1940. While examining the evidence, engineers found that when the wind hits the body of the bridge, it creates forces that oscillated the bridge, which caused instability (Gianni and Gazzola). Additionally, when these bridges were built, the environment they were in was drastically different than it is today. Although engineers took population increase