Yan was born in Zhejiang, and 1925- 12 was born in a family of railway workers in Shanghai. His father worked hard and gradually rose from clerk to clerk (now quite a civil servant), with a generous monthly salary and a well-off family. Yan's childhood was carefree. He is gifted and has excellent academic performance. 1937 during the "August 13th Incident", the Japanese invaders occupied Shanghai, their homes were destroyed by gunfire, their father lost his job, and their family's economy went from bad to worse. The whole family fled to the countryside of Nanjing and Yangzhou, almost destitute. Fortunately, my mother is as careful as silk. When she ran away, she made a sandwich in the wooden toilet she was holding. It was with some soft ornaments hidden inside that she helped the whole family through the difficulties. Since then, my brothers and sisters have sacrificed their studies to work and helped their father together, barely maintaining a family of eight and Yan's junior high school education. During middle school, Yan was not only among the best in academic performance, but also helpful. A classmate surnamed Zeng, whose family is well-off, has made rapid progress with Yan's help. His parents often invite Yan to study at Zeng's home, treat him as his own and take care of him in life. During the war years, the Zeng family had no business to do at that time, so they decided to move back to their hometown in Fujian, and urged Yan to go with them, and expressed their willingness to bear the expenses and help them complete their studies. At this turning point in life, in order to reduce the family burden, Yan decided to go to Longyan with the Zeng family and continue studying with Zeng's classmates as brothers. 1943 when he graduated from middle school, his father, who worked in Kunming, wrote to him to go to Kunming to go to college. Once again, the Zeng family generously supported him to transfer from western Fujian to northern Fujian to Jiangxi, Hunan, Guangdong and Guangxi, and then to Kunming via Guizhou. I worked hard all the way to Guilin and finally fell ill because of physical exhaustion. By this time, the money had been used up, so we had to sell our luggage to survive. Thanks to his father's old help, he continued to go to Kunming after his illness improved slightly. It was the autumn of 1943 when he arrived in Kunming. Because he missed the college enrollment period, his brother funded him to enter the preparatory course of Yunnan University first, and then he was admitted to the Department of Civil Engineering in The National SouthWest Associated University. 1945 Japan defeated and surrendered. At the beginning of 1946, the National Southwest Associated University, composed of three universities, was divided into Tianjin and North Plain. At that time, in order to win the hearts of the people, the Kuomintang organized the activity of "Yimin returning to his hometown" and sent Yimin back to Shanghai by truck or ship for free. Yan therefore returned to Shanghai, which coincided with college entrance. He applied for Tangshan Jiaotong University and Tsinghua University, two sophomores, and both were accepted. Because of the national The National SouthWest Associated University complex, he chose Tsinghua and graduated from 1949.

A promising young man

Yan studied hard when she was young and determined to save the country by science. When he was in middle school, it was during the Japanese invaders' invasion of China. He witnessed the weakness of the Kuomintang army and often collapsed. He hated the sufferings brought by the Japanese invaders to the people of China, and he deeply regretted the corruption and incompetence of the Kuomintang. He took an active part in some progressive student movements and the work of night school pickets. After transferring from National Southwest Associated University to Peiping, he was sincerely excited about the situation of the War of Liberation and had great expectations and hopes for the bright future of new China.

Yan graduated from Tsinghua University with excellent academic performance. He was hired by the school as the only fresh student in the civil engineering department who stayed in Tsinghua University as a teaching assistant. However, due to the party's "unified distribution" policy, Dean Zhou Peiyuan was embarrassed to explain to him that the school's letter of appointment was contrary to the government's policy of unified distribution of fresh graduates at that time. As a result, Yan was assigned to work in the bridge design department of the Ministry of Railways, and since then, he has forged an indissoluble bond with the bridge cause of the motherland.

Bao Jianfeng was honed.

1950 At the beginning of February, the Engineering Bureau was changed to the General Administration of Engineering, and Yan was assigned to work in the Bridge Unit of the Technical Department. After the establishment of Beijing Bridge Load Verification Station in April of the same year, he went to the verification station again. Because of his solid theoretical foundation, in less than a year, he independently carried out drawing, calculation, bridge material list and material test. The material list of bridge standard drawings is compiled according to a set of standard drawings designed by China Bridge Corporation. Although it has a perfect section size, the length of the material used is not indicated on the drawing. In strict accordance with the size, quantity and weight of all materials used in these standard drawings, detailed calculations are made and summarized into a list, which makes these standard drawings truly become classic stereotypes that are accurate, detailed, applicable and convenient for manufacturing and construction.

Strict and meticulous, down-to-earth work style has won praise and high praise from leaders. In terms of test work, from the design department to the technical department, he is responsible for drawing test curves and writing detailed test reports for all material tests submitted by the local foreign bureau to the Works Bureau. In the drawing work, he participated in the compilation of the appendix "Design Manual for Bridge and Culvert Engineering". The layout of his drawings is reasonable, the line thickness is even and clear, the font is beautiful, the dimensions are clear and correct, and the data in the bill of materials are accurate and comprehensive, which makes readers deeply satisfied. The leaders of the technical department see that such talents are rare. In order to further cultivate and sharpen him, they often send him on business trips to practice and get in touch with more practical things, so that his good theoretical accomplishment can be closely combined with practice.

After being transferred to Qiaoping Railway Station, Yan often went to the construction site. He went deep into Beijing and Tianjin for the first time, and did the load verification of Luodai Bridge, W- 14 Bridge and Baihe Bridge on Jin-Pu Line. For the second time, the load verification work of rattan beam bridge, Dawenhe bridge, Zhanghe bridge and No.87 bridge on Jingshan line was done. I have also done verification work for steel beams of various bridges in China (including Zhengzhou Yellow River Bridge, Jinan Yellow River Bridge and Harbin Sanshu Songhua River Bridge) (measuring dimensions, making up drawings, checking computations and checking grades).

After practice, Yan's wisdom and talent are fully revealed, and he works with ease, laying a solid technical foundation for his future work in bridge design.

Creating the First Prestressed Beam of China Railway

195 1 At the end of the year, the central government began planning and constructing the Wuhan Yangtze River Bridge during the three-year economic recovery period of the first five-year plan. As a top-notch talent, Yan was transferred to Wuhan Bridge Design Institute of the General Administration of Design to engage in design work. Under the leadership of experts such as Hu Shizhen, Wang and Liu Zengda, he participated in the design of Wuhan Yangtze River Bridge. Because of his comprehensive technical knowledge, he often has unique insights and initiative in analyzing and solving complex technical problems, and soon became the right-hand man of these experts.

In the design of open caisson of Daling River on Shenshan Line, he wrote a technical report of early open caisson calculation example and was promoted to a first-class technician. After that, under the leadership of chief engineer Liu Zengda, he surveyed the southwest railway bridge site and was responsible for the overall design of some bridges. 1954 became the first batch of young engineers promoted after liberation. 1956, he pioneered the design of the first railway prestressed concrete simply supported beam with a span of 23.9 meters on Xinyi River Bridge on Longhai Line, which is the first prestressed concrete bridge in China. He published the paper "Introduction to Design of Prestressed Concrete Beams for 23.9-meter Span Railway" in the fourth issue of Volume I of Journal of Civil Engineering 1956. Yan has both high technical level and strong organizational ability. 1956 served as the chief engineer of the branch company, presided over the overall design work of Yibin Minjiang Bridge, Chongqing Niujiaotuo Jialing River Urban Highway Bridge and Xinyi River Bridge on Longhai Line, and accumulated rich and valuable experience. 1958, his Beijing professional design institute was merged into the design department of Bridge Bureau (later changed to design institute) and still served as the chief engineer of the branch.

Nanjing Yangtze River Bridge started construction on 1959. The hydrogeological conditions of this bridge are complicated, and foreigners think that China people can't build it. To be prudent, Yan went to Shanghai to consult a professor modestly and discuss the vibration of bridges. I also asked Professor Zhou Nianxian about the theoretical problems of prestressed concrete structures, which was quite enlightening. As the design team leader in the design department of Nanjing Bridge Headquarters, he boldly pushed the design of prestressed beams to a new height, presided over and improved the general plan design of prestressed concrete T-beams for highways and railways with a span of 3 1.7 meters. At that time, Chen Jian, the chief engineer of Nanjing Bridge, proposed to do a static load limit test to verify the strength, stability and bearing capacity of this new prestressed beam. The results show that the beam designed by Yan completely meets the original design requirements, which fully reflects his innovative ability and technical level in prestressed beam design. This kind of beam has been used for more than 40 years, and no quality problems have been found, and the beam has not been replaced. Yan also participated in the design of the steel beam of the bridge on Chengdu-Kunming line and the overall design of Mayang Bridge on Chengdu-Kunming line. At that time, he was in a difficult economic period for three years. Due to lack of nutrition, he often drags his weak body to work and completes the task seriously and responsibly.

During the ten years of turmoil, Yan was hit by "re-education" without exception. 1948, when he was studying in Tsinghua, he went for an outing in Xishan. The students brought lunch and ate it in the square in front of a hotel, which happened to be where Chiang Kai-shek and Song Meiling also ate. When Jiang and Song got off the bus and saw these students from Tsinghua University, they took photos with their classmates as a souvenir. This encounter, this photo, has become a historical material to revisit Yan. Let him go to the May 7th Cadre School for inspection while working. Yan was open-minded and outspoken, which finally proved that he had no political activities. 1972 returned to the design institute and still served as chief engineer and chief engineer, and was later promoted to deputy chief engineer of the institute.

At that time, the national economy was destroyed by the Gang of Four, and there was not much business work. Yan has a solid foundation in English and Russian, taught himself German, French and Japanese, and read some foreign language books with great interest in his spare time. Russian classic The Silent Don, German book Wonderful Light, Selected Fairy Tales of Brothers Grimm, Fifty Days, etc. It is an excellent pleasure and pastime for him after work. He doesn't forget to recite foreign words when he comes home from work to do housework. His earnest and persistent learning spirit deeply infected his children. On business trip, he boldly communicated with Japanese passengers in the same carriage in Japanese. In his spare time, Yan devoted himself to studying foreign books, which laid a solid foundation for his future translation of professional documents.

Innovation of Prestressed Beam Design of Jiujiang Yangtze River Bridge Approach

From 65438 to 0976, Yan went to the north bank of Jiujiang Yangtze River Bridge to organize the design team, which was the third time that he presided over the design of the prestressed beam of the bridge approach. With his unique and profound thoughts and accomplishments, he presided over the design of a 40-meter-span box-type prestressed reinforced concrete beam, which is the first new bridge structure in China. For the ballastless box-type reinforced concrete prestressed beam on the track, because there is no influence of ballast thickness to adjust the camber, the normal rail surface elevation will increase, which may affect the stability and safety of high-speed driving. Therefore, if the pre-camber problem of prestressed beam can not be properly solved, it will affect the development and use conditions of prestressed beam.

Yan not only considers the stress, tension and crack resistance of this prestressed beam, but also considers the influence on the structure from the perspective of structural deformation. In the past, the deflection effect caused by live load was usually considered in the research of reinforced concrete beam deformation. For prestressed beams, he paid full attention to and studied the influence of the camber, especially in the design, manufacture, construction and use. According to the statistical data of camber (including elastic camber and creep camber) of T-shaped prestressed beam with a span of 3 1.7 meters designed and manufactured by Nanjing Bridge, he confirmed that the measured value of elastic camber is basically consistent with the calculated value calculated by structural mechanics formula of elastic theory. However, the creep camber is related to concrete gradation, environmental humidity, curing mode, prestress, tensioning age, section size and form (theoretical thickness of beam) and other factors, so its discreteness is large. According to the analysis of the measured data, he found that the creep camber of the same beam varies from bridge to bridge, and the same beam of the same bridge varies from beam to beam, and the difference between different types of beams is even greater. When studying the relationship between creep camber (ft) and elastic camber (fe), a creep coefficient (φ t) is introduced. The shrinkage and creep deformation values of concrete provided by the current railway bridge regulations are 33%, 40%, 60%, 75% and 80% of the ultimate value of 10 after tensioning. According to the example data of 3 1.7m prestressed T-beam, the creep coefficient is close to 1.0. Aiming at the prestressed box girder with a span of 40 meters, the author first observed the ultimate pre-camber of 50 beams with beam numbers from 025 to 075 * * for more than three years, and obtained the creep coefficient of 0.570, which provided a series of measured data to Mr. Yan in time. After consulting the information provided by the author, Mr. Yan decided to change the preset deflection of the beam-making pedestal from 70mm to 50 mm, and at the same time put forward strict requirements for the construction technology of this new type of ballastless pillow-less beam. Meng Qinghao, the chief engineer in charge of construction and manufacturing at that time, also paid great attention to the quality requirements of concrete materials, gradation, water cement ratio, maintenance and formwork erection. None of the 288-hole prestressed beams with a span of 40 meters (total length of 40.7 meters) have quality problems. After 40 years of operation, no major diseases have occurred so far. Practice has witnessed Yan's pioneering work in prestressed beams and made outstanding achievements. He timely summarized and wrote the paper "Some Problems in the Design of 40-meter-span Ballastless Sleepless Prestressed Simply Supported Box Girder", which was published in the third issue of Journal of Civil Engineering in 1982, and translated into English as an exchange paper and submitted to the 10th annual meeting of FIP held in New Delhi, India in 1986.

Writing, editing, translation and auxiliary work go hand in hand.

In order to promote the development of bridge science and technology, Yan has extensively absorbed advanced bridge construction experience at home and abroad. He has written a large number of monographs, or compiled monographs, or translated various foreign books and instructions in combination with his own work experience. His writing style is beautiful, and his articles are solid and concise, with the characteristics of many a mickle makes a mickle and sparse hair. He wrote many bridge monographs in English, Russian and Japanese, published them in influential foreign journals, and reported the new technologies and achievements of bridge construction in China to the world. At the same time, as a member of the International Bridge and Structural Engineering Association, he has participated in many large-scale international academic conferences, maintaining and expanding the international status and influence of China's bridge industry.

In his later years, he never bred negative emotions. Instead, he devoted himself to the desk work of the bridge and beam cause. He knows that his physical condition and age have entered the twilight of his life, watching the sunset in the western sky. He called from the heart: "Sunrise and sunset are the sun, but the sun will shine." "If there is heat, it is necessary to send a light." In his later years, he published more than 30 Chinese papers, 6 English papers/kloc-0, and 2 Japanese papers. Because of his quick thinking, profound knowledge and scientific and technological innovation, he left a lot of books, editors and translators in his life. His main works include: Foreign Prestressing Technology System, Modern Cable-stayed Bridge and Modern Suspension Bridge. There are more than 200 issues of bridge literature compiled by various countries, each with about 6000 ~ 20000 words. These precious wealth that he bought with all his life's efforts have provided an important guiding role for bridge construction and training of bridge professionals in China.

Yan has profound attainments and rich design experience in bridge theory, and is often invited by relevant universities and academic units. He has served as part-time professor of Southwest Jiaotong University, Changsha Jiaotong University, Changsha Railway Institute and Ningbo University, part-time doctoral supervisor of Huazhong University of Science and Technology, consultant of Bridge Engineering Science and Technology Information Center of Ministry of Railways, communication consultant of Guangdong Humen Science and Technology Consulting Company, invited expert of Technical Appraisal Committee of Ministry of Railways, and director or member of defense committees for master's and doctoral dissertations in many universities.

In his lectures and defense, his ideas are clear, his arguments are innovative, from the superficial to the deep, from the surface to the inside, his views and analysis are wonderful and forward-looking, which has won the admiration and conviction of the audience. He expressed his opinions at some meetings, which were outspoken, wise and incisive, profound and unique, which was inseparable from his profound knowledge and accumulated talent. He is indeed one of the few talented and thoughtful scholars we have ever met.

Do your best to die.

Only when you have both ability and political integrity can you be called a talent. "virtue" is like the source of water, while "talent" is the spray of water; "Virtue" is the root of wood, and "talent" is the branch of wood. Mao Yisheng, a bridge master, said, "Be a man first, then do things." Strict life style is decent, life is unpretentious and open-minded. Technically, I dare to demonstrate some sensitive issues clearly with theory, never say ambiguous words, dare to speak frankly, stick to my own point of view, and never fall to the fence with the wind. His pioneering and innovative achievements in prestressed beams are unique and extraordinary, which can be said to have made outstanding contributions to the development of Chinese bridge industry. 1998 He said, "I am 73 years old and have no plans to participate in international academic activities in the future. Of course, as long as my brain is still working, I will write some articles and do some translation. I hope the younger generation is no worse than us, learn foreign languages well, study technology hard, dare and be good at innovation, and shine on you is better than Blue. As the most populous country, China should have the largest number of participants in international academic conferences. The key is to train the younger generation to participate in and pay attention to international exchange activities, so that the motherland has a certain status and reputation in the international academic community. " He said so and did the same. He devoted himself wholeheartedly to the bridge cause, struggled all his life, and devoted himself to the translation of excellent foreign bridge construction articles until more than two hours before his death. On the morning of June 5438+1October 2 1, 2000, Yan was still reviewing and cutting and pasting the printed version of Bridge Information Materials. After lunch, he had a rest, and as usual, he continued to bury himself in his desk and take a nap in his bedroom until 3 pm. 17: 30 asthma attack, rescue failed. 17: 45 He left us forever at the age of 75. I really let go of the bridge building career I loved all my life!