Author: Mao Yisheng young friends, you should have heard the myth of the Cowherd and the Weaver Girl. Cowherd and Weaver Girl were originally two stars in the sky. It is said that they are all immortals and meet once a year at the Magpie Bridge on the Tianhe River. This "Magpie Bridge" is a bridge built by magpies. They are really outstanding bridge engineers-think how wide the Tianhe River should be! At the same time, we can also see the importance of bridges. Although it is a fairy, it also needs a bridge. It is said that the first bridge in the world (not counting Natural Bridge, where the tree fell across the river) was built by monkeys. At that time, no one. A large group of monkeys wanted to cross the river, so one climbed the tree by the river first, then the second one went up, holding the first leg, and the third one went up again, holding the second leg. One by one, one by one, in a long string of monkeys. Then the monkeys on the ground push this string of monkeys to swing, just like swinging, so they swing farther and farther. They throw this long string of monkeys to the other side of the river, and the last monkey on the tail hugs a tree on the other side, so that this long string of monkeys forms a bridge, and the monkeys on the ground can cross the river on the bridge. It is difficult to verify when humans started to have bridges, but what is certain is that a nation has a bridge when it has a culture, and the bridge is a symbol of culture. Our motherland has a cultural history of 4,000 years and a history of building bridges of 4,000 years. The most prominent one is "Zhao Zhouqiao", which was built more than 1300 years ago and is located near Shijiazhuang, Hebei. Since the bridge was built, it has been able to drive and walk and has never stopped. It looks like a modern bridge. Of course, there are bridges everywhere in our motherland, all kinds of bridges, and some bridge-building technologies are leading in the world. Can you imagine if we couldn't build a bridge in China, can our Chinese nation develop to this day? So we should thank the working people who built bridges among our ancestors. It is their wisdom and strength that enable us to see countless ancient bridges today, and modern vehicles can still pass on those ancient bridges. Bridges are the throat of roads. Without it, you can't cross rivers or valleys. For example, the Yangtze River, known as the "natural barrier" between the north and the south, was divided into several dynasties in the history of China because there was no bridge in the past. However, after the liberation of China, under the leadership of the Chinese Production Party, the Wuhan Yangtze River Bridge was first built on this "natural barrier", and then the more magnificent Nanjing Yangtze River Bridge was built. As for bridges built on the Yellow River, Huaihe River, Pearl River and other rivers, there are countless more. Bridge science and technology have developed rapidly in the world. It can be said that there is no bridge that cannot be built now. In terms of bridge length, there is already a bridge across the Great Lakes in the United States, with 22 17 holes and a length of 38 kilometers. To say that the bridge is big, Japan is building a cross-strait bridge with a hole1780m long. If this development continues, it will be possible to build a bridge on the 85-kilometer-wide Bering Strait between Asia and North America. People can drive around five continents, no matter what the barriers between the Pacific Ocean and the Atlantic Ocean are! Speaking of which, this is not surprising. What is a bridge? This is just a bench, with two legs supporting a board, which can bear the weight. Enlarge this bench and then "cross" a river or a valley to form a bridge. Here, the legs of the bench are piers, the feet that extend into the soil under the piers are foundations, and the boards of the bench are bridges. A bridge consists of these three parts. Vehicles and pedestrians on the bridge are carried by the bridge; The weight of the bridge depends on the pier top; The pressure of the pier is released into the soil or stone layer through the foundation. But there are many modes in three parts: bridge, pier and foundation. The bridge is supported by two piers, which can be straight and called "beam bridge" or curved upward and called "arch bridge". If two tall towers are erected on two piers, the steel wire rope crosses the top of the tower, and the bridge body is hung under the steel wire rope, and the car driver walks on the bridge body, it is called "suspension bridge". Ordinary bridge, but these three kinds, but each has endless new tricks. For example, there is a kind of "hyperbolic arch" in the "arch bridge", which was invented by workers in China. Among the "suspension bridges" are "cable-stayed bridges"; There is also a "suspension bridge", which hangs the whole bridge body on a rocky mountain by the river without piers. All these modern bridges are various and endless. There is no limit to human wisdom. Today, we think the new bridge is great, but the bridge tomorrow and the day after tomorrow is even greater. When we looked at the bridge today, we might wonder why people in the past were so stupid. Now let me be a visionary and draw a "vision" for the future bridge! Some people say that there will be so many planes in the future that everyone can fly in the sky, and there will be no trains, cars or bridges. I don't think so. Although the speed of airplanes is endless, the earth is only this big and the population is increasing. In the future, people will fly to the sky by plane. Can they fly fast? Therefore, the potential of land transportation and waterway transportation can not be exerted, and bridges are indispensable. However, the bridge then was not what it is today. Bridges in the future will be built quickly and well. A bridge as big as Nanjing Yangtze River Bridge can be built in a few months. At that time, all bridge building materials could be made into "standard parts" in advance by automation in the factory; When building a bridge, assemble them into piers in the water; Erect them on the pier to form a bridge and finish the work in one breath. I almost heard that I was going to build a bridge, and I saw the "flying bridge"! Bridges of the future must be built very cheaply. All kinds of "alloy steel" and high-strength "concrete" used now will be replaced by "polymer" new materials, which are light in weight and high in strength. The manufacture of bridge components should be automated. The underwater works of piers can be operated by "robots", which are dexterous and commanded by people on the water. The pier foundation doesn't need to sink that deep. In loose soil, a "coagulant" can be added to turn soft soil into hard soil. All kinds of machines and tools controlled by "computer" are used when bridging, and almost no manpower is needed. Of course, with these new technologies, the cost of this bridge will be very low. The future bridge must be built beautifully. The outline and components of a bridge will be arranged to add color to the earth and beauty to the mountains and rivers. The "component" of the bridge is no longer a straight stick, but soft, like a flower branch; The head and tail are not the same thickness, but the whole body is fat and thin. Each component is matched into various postures, each with a different color, making the whole bridge a beautiful picture. There are also small and exquisite pavilions on the sidewalk on the bridge, which makes people "better than walking around" when passing through this corridor. Bridges in the future must be built very low. Now the cost of building a bridge is often not the length of the bridge, but the height of the bridge. Because there is a boat under the bridge, if the water is high and the boat is high, the bridge will be higher. As soon as the bridge is high, the roads on both sides will be high, and the bridge will be built on the high road. Under this bridge, land is not water, which is called "approach bridge". The approach bridge project is often larger than the "main bridge" project on the water. At present, there is a "movable bridge" with a very low deck. You usually drive. When the boat crosses the bridge, you will open a "bridge opening" and close it when it crosses. However, due to the slow opening and closing of bridge opening, it is not convenient for cars to cross the ship, so this kind of bridge is cheap, but it is rarely used. Bridges in the future will be very different. The bridge holes can be made of extremely light materials, such as glass fiber reinforced plastic, and the machine for opening the bridge holes is much more flexible than now, so the time for opening the bridge and Guan Qiao can be greatly shortened. Moreover, there are automatic remote control devices on the bridge. When a boat crosses the bridge, it will automatically open the bridge opening and send a signal to the vehicles on both sides of the road in advance to let them know that there is a boat passing under the bridge. As soon as the ship passes, bridge opening will automatically close, allowing vehicles to cross the river quickly, and will not hinder land and water traffic. There must be a bridge without piers in the water in the future. The present Zhengzhou Yellow River Railway Bridge is about three kilometers long, and there are many piers in the river. But in the future, a long bridge like this, or a longer bridge, can cross the river with only one bridge opening if necessary. There are no piers in the river, which is of course much better for crossing the river. Such a long "span" bridge must be very high and most suitable for crossing the sea. When building a bridge in deep water in the future, it is not necessary to sink the pier to the bottom of the river, but to make the pier into a hollow box and let it float in the water. When there is no car on the bridge, it floats higher; When there is a car on the bridge, it will float lower. Of course, the height difference should not be too much to avoid driving difficulties. At the same time, all bridges should be firmly connected from one end of the bridge to the other end of the bridge, so that the whole bridge can be connected into a whole, and cars can walk on it without bumping. The bridge in the future is not necessarily straight, but curved, and cars will turn a big corner when crossing the bridge. This is because the roads at both ends of the bridge are parallel to the river and perpendicular to the bridge. If a straight bridge is adopted, it will be difficult to arrange "approach bridges" at both ends of the bridge. At present, there are "seven-bend bridges" and "nine-bend bridges" in the park, one of which bends to the left and the other to the right, in order to embellish the scenery, rather than make the bridge turn. The curved bridge in the future will be very different. The problem is the length of bridge opening. Each bridge spans two piers. If the bridge is bent too much, the pier will not support. It is conceivable that this curved bridge is suspended in the air by cables without the support of the pier below, and the cables are fixed in the Rocky Mountains on both sides. Isn't this curved bridge body free to rotate? In the future, there will be a small and light bridge that can be carried with you. When you meet a small river, you can set it up and cross it at any time. This kind of "pocket bridge" may be made of a very light, soft and extremely strong plastic, and made into a very thin tube. When air is pumped in by a pump, this tube becomes a very hard rod. Use some of these plastic strips to make the shape of the bridge in advance, fold it up and put it around, just like taking a raincoat. When you walk to the river, you can build a bridge by pumping air. Isn't it unnecessary to "look at the ocean and sigh"? There will be "flying without beams" in the future. At that time, the car was equipped with "buoyancy" equipment using high-pressure air. When driving at high speed, the car will leave the ground a little and move forward quickly without ground support. When it meets a small river, it can jump over it. There are more and more such winged cars. In the future, if you build a few piers in the water and the car jumps on the first pier, it will jump on the second pier because of the counterattack of the pier. No matter how wide the river is, it will be the most progressive bridge.

The author introduces:

Mao Yisheng (1896 65438+1October 9-1989 65438+1October 12) is a Chinese bridge scientist, civil engineer, educator and social activist. Tang Chen, a native of Zhenjiang, Jiangsu. My ancestral home is Mao Qian, and my previous business life was full of people, progressive thoughts and revolutionary tendencies. He once founded Nanyang Official Newspaper, a celebrity in Zhenjiang. Shortly after Mao Yisheng was born, the whole family moved to Nanjing. At the age of six, he went to a private school. At the age of 7, I studied at No.41 School, the first new primary school in China founded by Nanjing 1903. 19 1 entered Jiangnan Business School, 1 was admitted to Tangshan Road and Mining School. 19 12, Dr. Sun Yat-sen pointed out the importance of mining and repairing railways, and strengthened the road of "saving the country by science" and "building the country by engineering" in Mao Yisheng. From then on, he studied harder and regarded building the motherland as his own responsibility. The result of each exam is the first in the class, and the average score of each subject in five years is 92.5, which is rare in the history of this school. 19 16 graduated from the civil engineering department of Tangshan Institute of Technology. The following year, he received a master's degree in civil engineering from Cornell University. 192 1 received his doctorate in engineering from Gary Institute of Technology. His doctoral thesis "Secondary Stress of Bridge Truss" is called "Mao's Law" and won the "Fittis" Gold Research Medal of Cornell University. After returning to China, he successively served as Professor of Tangshan College of Jiaotong University (Tangshan Jiaotong University), Engineering Director of Southeast University, President of Hohai University of Technology, Dean of Beiyang Institute of Technology, Director of Engineering Department of Qiantang River Bridge in Hangzhou, Dean of Tangshan Institute of Technology of Jiaotong University, and Director of Bridge Design Engineering Department of Ministry of Communications of Kuomintang Government. After the establishment of People's Republic of China (PRC), he served as President of Northern Jiaotong University, Director of Railway Research Institute of Ministry of Railways, Dean of Railway Research Institute, Second Vice-Chairman and Honorary Chairman of China Association for Science and Technology, Chairman of Beijing Association for Science and Technology, Member of Chinese Academy of Sciences, Third Chairman of china civil engineering society, Senior Member of the 5th-7th China Bridge and Structural Engineering Society of Jiu San Society, and Member of the International Society of Soil Mechanics and Basic Engineering. In 1930s, Mao Yisheng's achievements in the engineering technology of Qiantang River Bridge made foreign counterparts look at the bridge-building engineers in China with new eyes. In 1950s, during the construction of Wuhan Yangtze River Bridge, Mao Yisheng served as the chairman of the technical advisory committee composed of Chinese and foreign experts, and solved 14 problems in the construction of Wuhan Yangtze River Bridge. 1979 When he was invited to visit the alma mater of Kalicky Mellon University, the president awarded him the "Outstanding Alumni" medal in recognition of his contribution to world engineering technology. 1982 was awarded the title of foreign academician by the National Academy of Sciences. 1933, he led the design and construction of Hangzhou Qiantang River Bridge, the first railway and highway bridge designed and built by China people. He also participated in the construction of Wuhan Yangtze River Bridge, the first modern bridge in New China. 1959 served as the head of the structural review team of the Great Hall of the People and contributed his own technology, experience and wisdom to this historic building. Mao Yisheng is an important founder of modern bridge engineering in China. As an educator, Mao Yisheng has served as a professor in five schools, the presidents of two universities and the deans of two colleges during his more than 20 years' educational career. He actively advocated popular science education and wrote many popular science articles such as Qiao Hua and China Stone Arch Bridge. Mao Yisheng was studious and enterprising since childhood, and was good at independent thinking. When he was 10 years old, a dragon boat race was held in his hometown during the Dragon Boat Festival. All the people watching the game stood on Wende Bridge. Because there were too many people, the bridge collapsed and killed many people. This unfortunate incident weighed heavily on Mao Yisheng's mind. He secretly made up his mind that when he grew up, he must build the strongest bridge. From then on, whenever Mao Yisheng saw a bridge, whether it was a stone bridge or a wooden bridge, he always saw enough from the deck to the bridge column. After Mao Yisheng went to school, he saw articles and paragraphs about bridges from books, so he copied them in his notebook. When he saw pictures about the bridge, he cut them out and pasted them on. After a long time, he accumulated several thick notebooks. After graduating from high school, Mao Yisheng was admitted to the Department of Civil Engineering of Tangshan Institute of Technology. After graduating from Tangshan Road Mine 19 16, he was sent to the United States for postgraduate study with the first place, and set off for Cornell University in September. Who knows that the director of the school's registration office proudly said: "Tangshan, China has never heard of this school, and you must pass the exam to register." . After the examination, Mao Yisheng got excellent grades, so he applied for the postgraduate of bridge major. Since then, the graduates of Tangshan Road and Mine School have been sent to Cornell University for postgraduate study, and they are no longer allowed to pass the exam. Mao Yisheng received his master's degree from Cornell University Graduate School on 19 17 and his doctor's degree in engineering from Gary Leakey Institute of Technology on 19 19. The title of the doctoral thesis is "Secondary Stress of Bridge Mechanics", which was first-class in the world at that time, so it won the gold medal for scientific research awarded by Gariji Institute of Technology. 19 19 12, 24-year-old Mao Yisheng resolutely returned to China and became a professor at Tangshan College of Jiaotong University. Mao Yisheng said: "Looking back on my study and life, this 14 year effort is like building a bridge, which has built a solid pier for my life." After returning to China, Mao Yisheng successively served as professor of Tangshan Institute of Technology, professor and director of engineering at Nanjing Southeast University, president of Hohai University of Technology (now Hohai University), president and professor of Tianjin Beiyang Institute of Technology, director of Jiangsu Water Conservancy Bureau, general manager and chief engineer of China Bridge Corporation of Ministry of Communications, president of North Jiaotong University and honorary president of Hebei Polytechnic University. 1933 to 1937, Mao Yisheng was the director of Qiantang river bridge engineering department, and presided over the construction of the first modern bridge with both highway and railway functions in China-"Qiantang river bridge". He solved the technical problems in bridge construction by "water injection method", "caisson method" and "floating method". Since then, Mao Yisheng has traveled all over the country, and his name has remained all over the country with the newly-built bridge. After five years' efforts, Mao Yisheng finally built the modern Qiantang River Bridge. September 26th is the 65th anniversary of the completion and opening of Qiantang River Bridge. Today, 65 years ago, the pioneer of modern bridge engineering in China, headed by Mr. Mao Yisheng, built the first modern steel bridge designed and built by China people on the Qiantang River, and set up an immortal monument in the history of bridge engineering in China. Qiantang River Bridge 1934 started. Zhejiang-jiangxi railway was under construction at that time. In order to connect the Shanghai-Hangzhou railway, a bridge must be built on the Qiantang River. Qiantang River is a famous dangerous river with extremely complicated hydrogeological conditions. Its water potential is not only affected by the upstream flash floods, but also restricted by the downstream tidal fluctuations. In case of typhoon, the river is often rough. The quicksand at the bottom of Qiantang River is 4 1 m thick and unfathomable, and is known as the "bottomless Qiantang River". Therefore, there is a folk proverb that it is impossible to bridge the Qiantang River, and the engineering and technical circles also think that it is very difficult to bridge the Qiantang River. When Mr. Mao Yisheng was a teenager, he was determined to build a bridge, but later he lost to the United States. He specialized in bridges at Cornell University and Kalicky Institute of Technology, and received his doctorate. He was sad to see that all the steel bridges on the rivers of the motherland were built by foreigners. He was determined to live up to the expectations of the people of China and build his own bridge in China. So he faced up to the difficulties and was appointed as the head of the department of bridge engineering, and asked his classmate Luo Ying to be the chief engineer, determined to win. The first difficulty in building a bridge is piling. In order to stabilize the bridge foundation, it is necessary to drive 1440 piles in 9 piers, which pass through the sediment with a thickness of 4 1 m and stand on the stone layer. The sand layer is thick and hard, so it can't go down lightly, but it is broken when it is heavy. Inspired by watering flowerpots to flush the soil out of small holes, Mao Yisheng adopted the "water jet method" of pumping water on thick and hard sediment to punch deep holes and then piling, and only 1 pile was driven day and night, which greatly accelerated the construction progress. The second difficulty in bridge construction is that the water flow is fast and the construction is difficult. Mao Yisheng invented the "caisson method", that is, the mouth of a box made of reinforced concrete sinks into the water, covers it at the bottom of the river, and then uses high-pressure air to squeeze out the water in the box. Workers dig sand in the box, so that caissons and stakes gradually merge into one. Build a dock on a caisson. It is not easy to place caissons. At the beginning, a caisson was washed downstream by the river, pushed upstream by the tide and scurried up and down. Later, the 3-ton iron anchor was changed to 10 ton, and the caisson problem was solved. The third difficulty is to erect steel beams. Mao Yisheng adopts the "floating method" which skillfully uses natural forces. The steel beam is transported between the two piers by boat at high tide, and falls on the two piers at low tide, which saves labor and time and greatly speeds up the progress. Qiantang River Bridge is a bridge that has been baptized by War of Resistance against Japanese Aggression. At the end of the bridge construction, the war of resistance between Songhu and Shanghai was tight, and Japanese planes often bombed. On one occasion, Mao Yisheng was discussing problems with several engineers and supervisors in the caisson of Pier 6, and suddenly all the lights in the caisson went out. It turned out that the lights on the construction site were turned off because of the Japanese plane bombing. Despite the enemy's bombing, Qiantang River Bridge was finally completed and opened to traffic on September 26th 1937. After the completion of Qiantang River Bridge, it has made outstanding contributions to War of Resistance against Japanese Aggression. The inscription on the bridge tablet records this tragic historical fact: "When War of Resistance against Japanese Aggression broke out, railways and highways were opened to traffic day and night under the bombardment of enemy planes. There are hundreds of thousands of vehicles supporting War of Resistance against Japanese Aggression in Songhu and rushing to transport materials, waiting for the people to cross the river safely. In the later stage of construction, knowing that the war situation was unfavorable, the explosive was buried together with the five-hole steel beam because empty holes were reserved on the pier that was the most difficult to repair. It was not until Hangzhou was neglected to guard and the enemy rode close that it was determined to detonate on 19371February 23rd. At that time, Mr. Wang left the oath of "no more bridges, no more husbands" and brought his own drawings and materials to the rear. " In order to stop the enemy, Mao Yisheng was ordered to blow up the bridge he built. What a tragic scene. After the victory of the Anti-Japanese War, Mao Yisheng fulfilled his oath and presided over the restoration of the bridge. Mr Mao Yisheng has been in charge of building, bombing and repairing bridges. Qiantang River Bridge was built in the anti-Japanese bonfire and regenerated in the world of peaceful construction. She not only wrote a touching page in the Chinese nation's struggle against foreign invaders, but also played an important role in the national economic construction. She connected the Shanghai-Hangzhou Railway with zhejiang-jiangxi railway and turned Qiantang River from a moat into a thoroughfare. Since it was opened to traffic for 65 years, she has made immortal contributions to the development of transportation and the prosperity of local economy in China. Qiantang River Bridge is not only a milestone in the history of Chinese bridge construction, but also the cradle of Chinese bridge engineers. Mr. Mao Yisheng turned the construction site into a school, absorbed a large number of students majoring in civil engineering to participate in engineering practice, and trained a number of bridge engineering talents for the country. Some responsible persons of some important bridge projects in China, such as Wuhan Yangtze River Bridge and Nanjing Yangtze River Bridge, have all experienced the baptism of Qiantang River Bridge construction. Qiantang River Bridge has demonstrated to the whole world the intelligence of China's scientific and technological workers and the ability of the Chinese nation to stand on its own feet among the nations of the world. The great patriotism, pioneering spirit of scientific and technological innovation, struggling spirit of overcoming all difficulties and obstacles, and enterprising spirit shown by the pioneers of bridge engineering in China in the construction of Qiantang River Bridge will always be valuable spiritual wealth that inspires us to make unremitting efforts for the prosperity and strength of the motherland. From 1955 to 1957, Mao Yisheng was the chairman of the Technical Advisory Committee of Wuhan Yangtze River Bridge, and he accepted the task of building the first Yangtze River Bridge in China. 1September, 1955, the bridge was officially started and completed on September 25th, 1957, one year and three months ahead of schedule. 19571June15th, the Wuhan Yangtze River Bridge was opened to traffic. Wuhan Yangtze River Bridge is a double-deck steel truss bridge for highway and railway. The upper floor is a highway bridge with a width of 22.5 meters, of which the roadway width is 18 meters; The lower floor is a railway bridge with a width of 18m. The length of the main bridge is1155.5m, and the total length is1670.4m together with the highway approach bridges at both ends. The bridge connects Jing-Han Railway and Yue-Han Railway, becoming the traffic artery running through the north and south of China, connecting the three towns of Wuhan into a whole, and ensuring the integration of the north-south railway and highway network in China. When the Great Hall of the People was built in Beijing from 65438 to 0958, Premier Zhou Enlai pointed out: "Mao Yisheng needs to sign the guarantee." Party and state leaders have great trust in Mao Yisheng, and Mao Yisheng is extremely responsible for the Party's work. He made a comprehensive review and accounting of the structural design of the Great Hall of the People, and finally signed it. Mao Yisheng studied, built and wrote bridges all his life. Published more than 200 articles in Chinese and foreign newspapers and periodicals. He presided over the compilation of "Technical History of Ancient Bridges in China" and "Bridges in China-From Ancient Times to the Present" (in Japanese, English, French, German and Spanish). He is the author of Qiantang River Bridge, Wuhan Yangtze River Bridge, Selected Works of Popular Science in Mao Yisheng (I and II) and Mao Yisheng's Works. Since 1954, he has been elected as a member of the first to fifth China People's Political Consultative Conference, a deputy to the National People's Congress and a member of the National People's Congress Standing Committee (NPCSC). 1987 10, gloriously joined the China * * * production party. He has made outstanding contributions to the bridge construction in China and the world. 1989165438+10/2 died.