Bridge Essay

America`s infrastructure has been a concern for years, but as populations begin to grow and structures begin to become outdated the problem has become more urgent. One focus of this infrastructure problem is bridges, which are growing weaker causing economic and social concerns. The primary controversy around these bridge failures is what is causing them and the potential they have to cause disasters. Moreover, this potential is why Americans should invest more into their infrastructure.

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

Calculations were performed to determine the effectiveness of the design of the platform. Allowing for a safety factor of 1.5 times the design weight of 10kg and considering the bridge must not be overdesigned; plans were made for the bridge to fail at 25kg, 2.5 times that of the design weight. According to the calculations, the bridge would hold a load of over 15kg and experience failure at 20kg in the members. These calculations were later disproven in the testing, breaking 8kg earlier than expected, due to unforseen errors. An analysis of the bridge design and calculations has been included at the end of this report.

There are many differences between our bridge and other bridges. One being location. Another one being that thing that was sacrificed for it. Another one being cost. Also another difference would be weight and capacity, and the size or length.

In the spring of 1989, the construction of the new bridge began. The base of the Trent River was a flotilla of barges carrying the workers, cranes and equipment needed to prepare the temporary pillars that would support the new bridge, as well as maneuver the huge steel girders into place for the new bridge. It was an awesome sight for the entire town, as we watched barges float the steel girders into the harbour, one section being 74 meters in length and two more that were 54 metres each. The new steel box girder bridge had a total length of 182 metres and weighed 2,950 metric tonnes (Anderson & Trenkler, 1991). Temporary cement pillars were poured to support

•September/2016 - After the layout of the gravel and topsoil has been accomplished the next process is to begin the building of any bridges over waterways and boardwalks to include low, wet spots that were unable to be dugout. Due to the use of equestrian or ATv usage the bridges will need to be structurally strong using items such as steel or high strength treated lumber.

Before steel bridges were built, trade had to be done through the use of ships and boats, slowing down the process. However, through the use of steel bridges, “the cost of travel and trade” has decreased by an enormous amount (“Introduction: What are bridges for?). Michael G. Barker, a professor in the College of Engineering and Applied Sciences at the University of Wyoming, collaborated with an engineering consultant and conducted some research on steel bridges. He studied two bridges-- one steel, and the other concrete, which were both built in 2012 in the same location, with the same dimensions, and looked very similar. In his study, he found that “the steel . . . superstructure provided a 25.8 percent cost savings, with an overall 19.3 percent savings in the total cost of the structure” than the concrete bridge. This clearly shows that steel bridges are not very costly as other types of

In 1989, an earthquake caused the top deck of the bridge to collapse. This has raised concern in recent years in the case of a large scale earthquake. During an inspection in September of 2009, a 1.5 inch crack was found in a structural truss called an eyebar. The system of the truss is meant to distribute report will describe the tensile load from the weight of the bridge over 4 eyebars. One of them being broken, this same load was now distributed between only 3 eyebars. Because these eyebars were not designed to carry extra load, it became crucially important to repair the eyebar as soon as possible. However, because the bridge is so old, its mechanisms were more complex than what would be designed now in the current day. The engineering company C.C. Myers was contracted to do the repair. C.C Myers decided to repair the eyebar by welding a crossbar to the saddles which had been placed on each end of the broken eyebar (Alfrey, 2010). Four tie rods were then bolted to distribute the tensile load (Reid, 2010). This repair was completed in only 70 hours (Carlsen,

During the construction, two half-spans being assembled 50 meters above ground level had a misalignment of 4.5 inches or 114mm in camber. It was suggested by John Holland & Constructions to use a kentledge to weigh down the higher section of bridge. It so happened that they had ten, eight tonne concrete blocks on site. These were placed halfway along the higher span to

Despite the fact that the breakdown of the Silver Bridge was a catastrophe, there were sure perspectives to the disappointment. Bridge investigations are presently more standard and top to bottom as a result of the Silver Bridge. Architects are currently more educated about consumption exhaustion and anxiety erosion, which permits better quality structures to be planned and constructed. With today's innovation, and additionally better outline systems and materials, there is trust that a Silver Bridge calamity will never again

Bridges collapse because either their design or construction fail to meet contemporary industry standards, or those standards are inadequate to ensure safety in the face of unexpected circumstances. (Wallace, Jonathan).

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

The total weight of the bridge is 804,672 tonnes (887,000 US tons) about 80,000 tonnes (88,000 US tons) is steel;

The building of the bridge and roads connecting to it has been contracted to Forth Crossing Bridge Constructors (FCBC). This is a collaboration of four experienced civil engineering companies – Hochtief solutions AG, Germany; Dragados, Spain; American Bridge, USA; and Morrison Construction, Scotland.

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.