3. Investigation and Findings The government of Quebec established a commission of inquiry on October 3, 2006 to investigate the causes behind the collapse of the De La Concorde overpass. The commission consisted of former premier Pierre Marc Johnson (President) and other two commissioners by the names: Mr. Armand Couture (Engineer) and Mr. Roger Nicolet (Engineer). The commission, while trying to analyze situations before, during, and after the incident: Held public hearings where 58 witnesses testified, Studied scientific researches done by experts delegated by the commission, Analyzed various documents and contacted many of the parties involved in the design, construction, maintenance and inspection of the bridge. According to the investigation report, what actually led to the collapse of the overpass was shear failure at a thick concrete section of an abutment cantilever. The failure was caused by chain of events attributed to problems in design, construction and supervision, maintenance and other environmental factors that contributed to such a …show more content…
For its realization, it was required to construct two cantilever thick concrete sections hanging from each abutment. In this case, two deficiencies with regard to reinforcement design were identified: improper detailing of rebars and absence of shear reinforcement in the middle of the concrete section, the later though was not required by the code of practice at that time. Therefore, improper detailing that caused the concentration of numerous bars in the same plane created a plane of weakness, which any cracks developing from it couldn’t be intercepted due to the absence of any shear reinforcement bars in the middle of the concrete slab. As a result, the bridge lost its ductility and was destined to a sudden crushing failure that prohibited any precautionary measures. (Johnson G. ,
Without a concrete reason for the bridge's failure, every suggested reason was researched until proven incorrect” (Silver). There were many reasons that were suggested, but could not be proven correct due to the collapse. Wikipedia states that “A small crack was formed through fretting wear at the bearing, and grew through internal corrosion, a problem known as stress corrosion cracking.” The failure of the bridge was caused by a defect in one of the eye-bars on the north side causing the other side to collapse as well. “Stress corrosion cracking is the formation of brittle cracks in a normally sound material through the simultaneous action of a tensile stress and a corrosive environment.
An Occurrence at Owl Creek Bridge is split into three sections. In the first section, Bierce describes in detail the situation, a youn...
The reasons for the collapse are to be found in the acts and omissions of those entrusted with building a bridge of a new and highly sophisticated design.
The failure tragically occurred on the night of the dance party, with the added weight of all of the partygoers proving too much for the supporting bolts to handle. At 7:05 P.M. one of the upper walkway’s supporting bolts failed causing the rest of the connections to break and “unzip” (Chronology). The upper walkway crashed onto the lower walkway causing both to fall onto the lobby floor below. Numerous key factors are often cited as having left the construction project vulnerable to such fatal design flaws.
The I-35 Bridge collapse in 2007 was not the result of a single safety precaution being overlooked; it was primarily due to a miscalculation by the original design team, Sverdrup & Parcel and Associates. While the accountability can be placed on Sverdrup & Parcel and Associates, the only way to learn from such disasters is to delve deeper into the root cause and determine why this minute, yet extremely important, detail was overlooked for over 40 years.
The article “Hyatt Regency Walkway Collapse” brought attention a famous case of failed structural design and engineering, analyzed the history of the building’s design and construction, and considered what is to blame for the accident that occurred.
The Lac-Mégantic derailment occurred on July 6, 2013 in the town of Lac-Mégantic, which is located in the Eastern Townships of the Canadian province of Quebec and has population of about 6,000.The disaster occurred when a 74-car freight train, through a complex series of events, ran away and derailed. The events that led to the disaster included an inadequate repair on the lead locomotive’s engine, a lack of the necessary amount handbrakes, weak safety training for Montreal, Maine & Atlantic (MM&A) staff, and a failure of federal oversight.
Golden Gate Bridge held the title as one of the longest bridges for a reason. It has a total length of 2,737 meters with a width of 27 meters. It also has a clearance of 67 meters for ships to pass by. Besides its incredible dimension, its architecture also plays a tremendous role for its beauty. The bridge employs art deco style, a chevron or beveled shape, used to add visual effect. The concrete structures at the ends of the bridge have chevron form as well as the concrete at the base of the towers. There are two shafts in each tower, 90 feet apart decreasing in width as they go up. The two shafts are connected by cross bracing and having four horizontal struts above. The bridge’s art deco design and towers were designed by architect Irving F. Morrow.
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 the wave. On the last day of the bridge's existence it gave fair warning that its destruction was eminent. Not only did it oscillate up and down, but twisted side to side in a cork screw motion. After hours of this violent motion with wind speeds reaching forty and fifty miles per hour, the bridge collapsed. With such a catastrophic failure, many people ask why such an apparently well thought out plan could have failed so badly?(This rhetorical question clearly sets up a position of inquiry-which iniates all research.) The reason for the collapse of the Tacoma Narrows Bridge is still controversial, but three theories reveal the basis of an engineering explanation. (Jason then directly asserts what he found to be a possible answer to his question.)
In Flannery O’Connor's "A Good Man is Hard to Find," the characters are utilized as vessels to explore the complex interplay between egocentrism, religion, and morality. The narrative nimbly unveils the theme that the concept of a 'good man' is elusive and flawed, which in return challenges the reader to grapple with the inherent complexity of defining what is “goodness”. O'Connor's mastery of language, imagery, foreshadowing, irony, and symbolism strengthens this theme, supported by an intricate use of repetition and an omniscient narrative perspective. It can be seen at the heart of the story, there stands the grandmother, who is portrayed as a manipulative character whose actions drive the plot forward. It is through her character that O'Connor showcases the ways in which different experiences
In her essay,”Importance of the Golden Gate Bridge,” Stephanie Stiavetti suggest that “It maintained this point of pride for nearly 25 years until the Verrazano- Narrows Bridge was built in New York in 1964. Today, this historic San Francisco landmark holds its place as the second largest suspension bridge in the country, behind Verrazano Narrows.” Back then, experts thought that it would be impossible to build a bridge across the tides and currents in that area because strong currents and tides would make construction extremely difficult and dangerous. The water is over 500 feet deep in the center of the channel, and along with the area's strong winds and thick fog, the idea of building a bridge there seemed nearly impossible. Despite all of the problems of building a bridge across the Golden Gate, Joseph Strauss was named as lead engineer for the project. Construction began January 5, 1933, and in the end cost more than $35 million to
built, and after half the livestock and people had left the dry area, the bridge collapsed,
Reinforced concrete is stronger than basic concrete. Steel reinforcing bars known as rebar is incorporated in the concrete structure to act together in resisting the force. The steel reinforcing bars absorbs tensile and compression because plain conc...
The factors that lead to the “collapse” of civilizations are almost directly related to those that created it. Archaeologists characterize collapse by a number of elements, some of which we have evidence for, others we do not. Most archaeologists are unsure of exactly what caused the decline of most civilizations in the ancient world, yet there are many clues to some of the events that could have contributed. The collapse of the ancient Roman Empire, the Mesoamerican Mayan, and the Egyptian cultures will be discussed in the following paragraphs, with a focus on the uniqueness of each.
... although we may never be able to understand exactly what soil failures can occur when a natural disasters take place, as time goes on and testing instruments and materials advance we will hopefully have a better understanding of what we can do to avoid soil failures and come up with a better and more sufficient method of improving the soils structure and strength permanently. While researching the information for this report I feel I have a much better understanding for construction geo-technics and foundations especially regarding the deformation, liquefaction and pile information related to this specific event. I hope to carry the information I have learned from this event into the construction field and apply them towards an authentic project that’s taking place and know that the information, regarding soils, I have given input on will be precise and accurate.