1940 Tacoma Narrows Bridge

The city made notifications not initially planned out and ultimately adding more dead load of the bridge which led to the collapse under too much load the bridge was intended to take. They also added railings to the bridge that did not meet current safety standards in 1998. By replacing them, it added more load to the bridge. During their last renovation of the bridge before the collapse, more concrete was going to be added. They chose to use mixing truck to pour concrete, but Minnesota specifications said that pouring of concrete was to be done on site and mixing trucks could not be used on state bridges. The company's actions to place trucks all over the site to pour their concrete while specifications said that concrete was to be mixed on site without trucks, shows how the actions taken by the company was not morally right in considering state regulations. Bridge construction inspectors determined that the concrete specifications meet required standards and consequently they determined that it was okay to place the materials on the bridge for the

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 report debates the Tacoma narrows bridge failure and the different theories of how it came about, using information about what type of bridge it is and the forces acting on it before and during the collapse. It also discusses ways in which the failure could have been avoided, from changes in the design to modifications to the bridge after its construction.

Sometimes the wind would not be perpendicular, in which the oscillation of the bridge was less, but there was still some oscillation. On November 7th, 1940, the Tacoma Bridge collapsed because the oscillation of the bridge became extreme. The oscillation of the bridge was caused by a wind speed of 42 mph (HistoryLink.org). After, approximately, an hour of a corkscrew like motion, the bridge collapsed into Puget Sound. This marked a huge turning point in the design of suspension bridges from that point in time to current time.

Hernando DeSoto Bridge on Interstate 40. The bridge on Interstate 40 is on the exit route from Memphis, as well as Tennessee completely, as it separates the city and state from the state of Mississippi. There were over 1,000 protesters that day in Memphis that marched against the violence against black men and women and black children. While this march was considered peaceful, they put many officers in danger by shutting down traffic on a busy Interstate 40 bridge. The violence in Memphis stints from great racial strain in the community due to the amount of crime and black on black killings that lead officers into very dangerous situations.

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.

The I-35W Mississippi river bridge also known as Bridge 9340 officially was an eight-lane, steel truss arch bridge which carried the Interstate 35W across the Mississippi river connected the downtown east and Marcy-Holmes. Its construction began in the year 1964, was finally opened in 1967. It connected the northeast of Metrodome on its south end and the University of Minnesota on the North end. The bridge was the boundary of “Mississippi Mile” downtown riverfront parkland. The north foundation of the bridge was near the hydroelectric plant built in 1988. The south abutment was in an area polluted by the coal gas processing plant. There weren’t any mentions of this in the failure investigations. The bridge was a continuous truss bridge that had a total span of 1,907 ft. It was an 8-lane bridge having a width of 113.3ft. and was 115 ft. high. It was designed by Sverdrup & Parcel to 1961 AASHO (American Association Of State Highway Officials) standard specifications. The construction contract worth more than US $5.2 million at the time, went to Hurcon Inc. and Industrial Construction Company, which built the steel trusses and deck. The piers were not built in the navigation channel instead the center span of the bridge consisted of a single 456- foot steel truss over a 390-foot channel being the longest span of the bridge.

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.

In 1919, a study was begun to see if it would be possible to build a bridge across the Golden Gate. Michael O’Shaughnessy was the San Francisco city engineer. He was in charge of the rebuilding of the city after the devastating 1906 earthquake that destroyed much of the city. O’Shaughnessy knew the need for the city to have bridges. Most said it could not be done and others said it could be done but “it would cost about $100 million to build it” (Barter 23). O’Shaughnessy and Strauss, both wanting the same thing, got together. After the two consulted, they figured the only way to bridge the channel was to use a suspension bridge.

Wald is a reporter for New York Times. He mentioned the reason for why the interstate 35W bridge would collapse into the Mississippi River was because there was a mistake in the bridge’s design. The reason was that there were few metal plates were too thin to be a junction of the bridge. So, these weak junctions caused the collapsed of the 35W bridge and let to 13 people killed during this accident. The Interstate 35W bridge had been existed for over 40 years after it was constructed in 1960s. After a long period of time, the bridge began to have weak points and require frequently repair for the bridge to make it safe. However, the changes made in the bridge made the bridge even weaker. After the bridge was collapsed into the Mississippi River, the National Transportation Safety Board held a conference to discuss the investigation about the cause of the bridge collapsed. Mostly, the investigators would

Bridges are structures that become very susceptible as time passes. In Oregon there have been many bridges being identified to be seismic vulnerable. In an article by Ed Jahn, he sates, “nearly sixty percent of state-identified lifeline bridges likely to collapse or be potentially taken out of use after a quake” (Jahn). Bridges are a whole different story because they aren’t easy to be re-evaluated when they are used constantly by people to get around. The problem with many of these structures, though is that more than half of these bridges were built before 1970 (Jahn). Because of this they aren’t reinforced with new building codes making them highly vulnerable to any disaster to the point of collapsing. It isn’t an easy thing to fix the problems with a bridge because many seem stable but are still at great risk. It is known that “Today, they're still building fracture critical bridges with the belief that they're not going to break,” (Rosenker). Even when a bridge is being identified to see if it’s stable a lot of the time they are thought to be ok, but are really in a bad condition. Because they aren’t fully evaluated, and if a disaster were to hit in a certain location it could cause the bridge to

Additional details of the film and video analysis can be found in the November 2015 issue of the Physics Teacher, which also includes further description of the Armistice Day storm and the strong winds that earlier had caused the Tacoma Narrows Bridge to oscillate, twist, and collapse into the waters

Improperly designed welds on the cross bracing led to the failure of 3 of the bridge’s beams. Extremely cold weather and constant morning rush-hour traffic also added to the list of causes. This caused the bridge to buckle inwards.

About eighty years ago, engineers were able to build a bridge on time and within budget with no problem; today, most of the projects take extra time and money to finish. What exactly happened between now and eighty years ago that caused such a drastic shift? It is clearly not the engineers nor the technology; in fact, those have only improved over time. Today, engineers are faced with much more than designing and building the infrastructure, as they were before. They compete with politicians for funds, fight for the safety of workers, and protect our environment by adhering to the numerous laws and acts set forth by the government. In the future, we can only expect more costs, longer time periods for projects, and an increase in costs and

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