Clifton Suspension Bridge

When bridges are poorly constructed, they may fail due to load they carry, collision by derailed trains or even by vehicles that lose control leading to catastrophic incidences. However, if bridges are well-constructed, the chances or injury are greatly minimized in the event of an accident. Discussed in the subsections are the requirements of AS 5100 standards in relation to cable-stayed bridges and include design requirements for bridges, bridge aesthetics, bridge functional requirements, bridge component design requirements and bridge construction

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.

Suspension bridges usually experience torsional forces during very windy conditions where there are high wind speeds, this can create a twisting force causing the deck to rotate resulting in the bridge experiencing shear stress. (Bagga

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.

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

Arielle: (show drawing) In the end we had made a beam bridge out of hot glue, cardboard and popsicle sticks. We used the cardboard because it is a flat surface and is very light. However, cardboard is not strong enough on it’s own. We then decided to use hot glue to attach the popsicle sticks to the

Although the Tacoma Narrows Bridge is oft considered “the most spectacular failure in bridge engineering history”, it was far from being the first unsuccessful suspension bridge. There were ten prior suspension bridges that failed due to unaccounted wind/oscillating forces. However, the Tacoma Narrows Bridge collapsed 50 years after the last bridge, and it was the most expensive and longest- more than double any previous bridge- that is the reason why its failure is so significant. The remains of this bridge now serve as “one of the world’s largest manmade

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

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

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.

The first change was that the piece at the base of the bridge located on either side was moved from the inside to the outside on the bottom of the bridge. I changed this because it was easier to glue the two sides of the bridge together if it was on the bottom. This change didn’t drastically change the bridge but it did make the bridge closer to the 2cm block it had to be under at the starting point. The second change that I added the braces to the wood pieces that made up the triangles. This helped my bridge because it made it easier to keep the pieces of the bridges together. It also made the construction process cleaner and easier so I would be able to execute the rest of the design with more success. The third and final change I made to my design was that I removed the piece of wood that was connected to the top of the bridge and the braces. I made this change because I thought that the help it would provide to the bridge would not be worth the added

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.