Causes Of Failure Of Bridge Roof Vibration

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

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

Suspension bridges were important before 1940 and are still important today. Major cities such as San Francisco, and Manhattan both have a suspension bridge. Suspension bridges are,” a bridge having a deck suspended from cables anchored at their extremities and usually raised on towers” (dictionary.com). Due to the fact that suspension bridges are not completely supported throughout the length of the bridge, past bridges were unsafe. For example, the Tacoma Narrows Bridge was a suspension bridge opened on July 1st, 1940 (Mark Ketchum). This bridge marked a huge point in suspension bridge safety and engineering, because in collapsed approximately four months after it was opened (Parsons). The collapse caused such a shock, that suspension

In Washington, the Interstate 5 bridge, which crossed the Skagit River, collapsed last month. The damage of this accident included two cars broke and three persons injured. According to officials, the bridge fell into the river after the large truck hit a beam. The bridge had a risky condition called facture critical. The U.S has a lot of bridges; however, nearly two thousand bridges were built between the middle of 1950s and the 1970s, so those ones are obsolete bridges. In addition, back then, the government cut corners in bridge buildings to cost reduction. Although gas and diesel taxes attempted to allocate to restored the bridge, the government cloud not collect money enough to repair the bridge because people began to use efficient vehicle.

We are pleased to attach our tender to the observation deck. This report deals specifically with the engineering design of our design at the new

Furthermore, when the millennium bridge opened within the first weekend around 100,000 people had crossed the bridge. Due to such heavy traffic, this lead to something called resonance. Resonance is when the input vibrations frequency coincides with the natural frequency of the structure itself, causing large deflections to develop. The issue caused the bridge to undergo a swaying movement; hence led to its closure. After extensive research and analysis, it was found that the movement was caused by synchronized pedestrian footfall. To prevent this there were two options taken into account the lateral stiffening and the damping; both were used in order to increase the natural frequency of the structure so it did not match the footfall. In addition structures called fluid-viscous dampers and tuned mass dampers were installed to control both horizontal and vertical movements.

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

Several students are doing Science Fair projects at Woodstock Middle School and I am one of the seventh grade students. The topic I shall be doing is on how bridge structure affects the weight bearing capacity. I chose this specific topic to guide bridge builders in the right direction on what bridge is safest for public use. The key topics I plan to research on include the following: Beam, Warren Truss, suspension, cable-stayed, and arch bridges. I shall use the scientific method to guide me through this process.

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,

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.

As one looks across a gap in between two land masses, a thought of how one could cross comes to mind. When one thinks of this, a bridge comes to mind. Although they might now know what kind, a suspension bridge is the first idea. They picture something like the magnificent Golden Gate Bridge, one of the most recognizable structures in all of the world. Although suspension bridges now span over miles, they had very humble beginnings. The evolution and expansion of suspension bridges is a topic worthy of this very essay.

It is no secret that earthquakes are natural disasters that can have devastating consequences. Earthquakes are defined as “vibration of Earth produced by the rapid release of energy” (Lutgens and Tarbuck, 2014, p. 548). These vibrations are the result of seismic waves, which are emitted from the epicenter during an earthquake (Lutgens and Tarbuck, 2014, p. 191). The epicenter is defined as the “location on Earth’s surface that lies directly above the forced of an earthquake” (Lutgens and Tarbuck, 2014, p. 548). Seismic waves are not all the same. There are two types used to determine the location of the epicenter: P-waves and S-waves (New York State High School Regents Exam Prep Center, n.d.). According the the New York State High School Regents Exam Prep Center, P-waves, or primary waves, travel faster than S-waves and go through solids liquids and gases. They are compressional waves and are smaller than S-waves which are shear waves (Southern California Earthquake Center, n.d.). As a result of P-waves moving faster than S-waves, P-waves reach measuring devices more quickly than S-waves (New York State High School Regents Exam Prep Center, n.d.). According the the U.S. Geological Survey (2016), seismograph is used to “detect and record earthquakes” by using a hanging mass over an unmoving base, so the mass records on the base when the ground moves.

Superstructure bears the load that is being passed over the bridge and it transmits the forces caused by the same to substructure. Load received from the decking is transferred on to the substructure by Bearings. They also distribute the load evenly over the substructure material as it may not have sufficient strength to bear the superstructure load directly. Piers and Abutments are the vertical substructures which transfer the load to the earth in the foundation. Wing walls and returns are constructed as the extension of

The choice of a design concept for a bridge foundation is guided by various factors; several of these