Foreword
Under the green hills on the Klook, before sailing on the green waters.
The transportation in ancient China had a certain scale in the pre-Qin period. The transportation vehicles such as "carriage and horse", "walking" and "boat and boat" were already in use during the Shang Dynasty. With the continuous development of technology, people's travel has become more and more convenient. The so-called "building a boat as a beam does not show its glory." Since ancient times, our country has attached great importance to bridge construction. It is not only sturdy and durable, but also very beautiful.
Throughout the world, many bridges are beautifully crafted and worthy of human works of art. "One bridge spans north and south, and the sky becomes a thoroughfare." A bridge is not easy to build, and it is not easy to use it steadily all the year round. If there is a slight difference, the consequences will be unpredictable. There used to be a bridge in the United States. Because of an engineer's decision, 19,000 tons of steel bars fell from the sky, which directly caused the death of 75 people and became a major disaster in the history of architecture.
The finalization of the construction of the bridge
This bridge is called the Quebec Bridge. It was jointly designated as a historical monument by the Canadian and American Engineers Association in 1987. It was ill-fated, collapsed one after another, was rebuilt again, and once became a punch-in place for engineering scholars. It was also awarded the title of historic site in 1996. What happened on this bridge? Is it worth being so commemorated?
This bridge spans the St. Lawrence River, which was a very important transportation hub before the bridge was built. In the summer, the boat traffic on the water is very lively, but in winter, the water freezes. If you want to cross the river, you have to wait for the river surface to thaw before you can sail again. As early as the 18th century, local residents often complained about the inconvenience of transportation and urged the relevant authorities to build a bridge. However, the waters of the St. Lens River are special. The water here is so fast that it is very difficult to build a bridge. In addition, because the water surface is very wide, it is 3,200 meters wide even at the narrowest part of the river, but because of the high voices of the residents In 1887, the construction of the bridge was put on the agenda.
People attach great importance to the construction of the bridge, the whole project is in full swing, and Quebec businessmen and some politicians also paid for the bridge. With the cooperation of many senior people,Quebec Bridge Company took over the construction of this bridge and received 1 million US dollars in financial support.
The bridge collapsed for the first time
Because this factory was very troublesome to build, many designers have been controversial about the construction plan of the bridge. For this reason, the company specially invited the famous bridge architect Theodore Cooper at that time. Improved design and post-supervision of the project as a whole. In the design proposal originally submitted at the beginning, the main span of the overall bridge was 487.7 meters, but it was opposed by the designer. He comprehensively evaluated the topography of the bridge. It is believed that the overall span should be extended to 548.6 meters.
His reason is that this can increase the stability of the bridge piers, reduce the impact of winter freezing on the piers, and save the next cost. Because of his high profile, everyone followed his advice, but this modification has caused serious consequences. After the change, the force on the overall bridge became unbalanced, and many components were squeezed and deformed. Originally, someone discovered this problem during construction and wrote a report, but it did not attract enough attention from the high-level buildings. Fortunately, it collapsed before it passed.
On August 29, 1907, when the workers were about to stop work and walk towards the shore, suddenly there was a loud bang behind them. At that time, the people on the bridge hadn't reacted, and they felt like the sky was spinning and falling in. Out of the river. The entire bridge sank as a whole, and a total of 19,000 tons of steel collapsed instantly. The loud noise from the collapse of the bridge made the citizens of Quebec City, ten kilometers away, hear clearly. At that time, there were 86 workers working on the bridge. Many workers were either crushed to death by broken steel bars or washed away by the rushing river. According to later statistics, 75 workers lost their lives in the accident.
Bridge was built twice again
After this accident, the construction of the bridge was temporarily put on hold. It was not until 1913 that the construction of the new bridge was restarted. The design was much more cautious than the original design, and the cross-sectional area of the compression member was doubled compared to the original design, but even so, it still did not prevent the tragedy from happening again. In September 1916, when a support member was installed,The bridge broke again, the whole bridge broke from the middle, and fell into the St. Lawrence River again. This time, another 13 innocent workers were killed.
The Quebec Bridge, which suffered two collapses, had to start construction again. It was finally completed and opened to traffic in 1917. In 1922, seven engineering colleges in Canada made a joint decision to buy all the steel materials that collapsed during the construction of the bridge, and processed them into rings, which were given to them. Students studying engineering. The original intention was good, but in the actual operation, the workers found that the structure of these steel bars was very strong and difficult to be made into a ring, so the college decided to use other materials instead. In order to let the students remember the bridge that collapsed twice due to design failure, the ring was specially made into a twisted steel bar shape to remind those engineering students that they must cherish life, build carefully, and do not repeat the mistakes. Innocent workers lost their lives.
References: "Book of Songs. Daya. Daming"
"Shui Tune Song Tou·Swimming"
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