(1) presided over the completion of the major project of the national western transportation construction science and technology plan, "Study on complete sets of technologies for highway construction in expansive soil areas", put forward the theory of balanced moisture content of expansive soil, developed the comprehensive treatment technology of flexible support of expansive soil cutting slope and physical treatment technology of embankment, and developed the theory and technology of highway expansive soil engineering.
(2) The evolution model of asphalt pavement surface deflection attenuation and the limit state design method of asphalt pavement structure are put forward for the first time, and the design standards and methods of asphalt pavement with design deflection as the index and the new design method of asphalt pavement with large and medium repair strength are put forward, which improves the design theory and method of asphalt pavement in China, and all the research results are incorporated into industry norms.
(3) The viscoelastic damage characteristics of asphalt mixture are studied for the first time at home and abroad, a new method to determine the stress level of fatigue test based on the real stress in damage mechanics is put forward, and the corresponding fatigue equation is established, and the nonlinear fatigue damage theory and analysis method of asphalt mixture are established, which lays the foundation for the revision of asphalt pavement design specification.
In addition, Professor Zheng Jianlong has also made fruitful achievements in subgrade degeneration control technology, highway geosynthetics application technology, asphalt pavement anti-crack design, asphalt mixture modification technology, pavement maintenance management technology, nonlinear theory of composite plate shell and so on.
Overcoming the worldwide problem of "road cancer", expansive soil technology won the first prize of national scientific and technological progress in 2009.
It is the first time for ordinary local colleges and universities to win the first prize of national scientific and technological progress in Hunan.
The creator of this miracle is Professor Zheng Jianlong, President of Changsha University of Science and Technology, and his research team. From 65438 to 2005, Professor Zheng Jianlong led more than 380 scientific and technical personnel from 25 units across the country, and finally "cured" the "malignant tumor" of expansive soil in highway construction, which has been treated by experts at home and abroad for a long time! The direct economic benefit reached165438+75 million yuan.
"Cancer" is rampant, and the annual loss exceeds $654.38+0.5 billion.
"Expansive soil is a kind of special soil rich in expansive clay minerals. Under the alternating action of wet and dry environment, its volume expands and contracts obviously and its strength decays rapidly." Professor Zheng Jianlong explained that expansive soil swells when it meets water and cracks when it is sunny, which is the biggest nemesis of highway construction. There are 46 countries in the world and 26 provinces and regions in China, and this special soil is abundant. When using this soil to build roads, there will be phenomena such as slope collapse, subgrade subsidence, road damage and structural collapse, and the damage will be repeated many times. In addition, it is also very harmful to shallow light structures such as railways, housing buildings and water conservancy facilities. The research on Sino-Canadian cooperation shows that the annual economic losses caused by Sino-Canadian cooperation are as high as 654.38+0.5 billion US dollars. In the past, chemical improvement, soil replacement and rigid support were often used, which not only had high cost, long construction period and great construction difficulty, but also caused serious soil erosion and ecological environment damage.
What shall we do? As early as 1992, Zheng Jianlong, who teaches at Changsha Jiaotong University, began to pay attention to this issue. 1993 applied for Belgian postdoctoral fund, became a visiting scholar of Belgian Road Research Institute, and began to think and study this topic systematically. In those years, expansive soil became a word that Zheng Jianlong thought of almost every day.
Give up "rigid governance" and choose "flexible governance of inflation"
The main problem in dealing with highway expansive soil is actually one: how to make this seemingly ordinary soil not expand, crack, collapse or sink under any weather conditions. Therefore, Zheng Jianlong and his colleague Professor Yang Heping led students to do numerous tests and experiments in the laboratory and field, and creatively put forward a new concept of "treating swelling with softness" in slope treatment.
What do you mean? It is to abandon the method of "rigid treatment" to strengthen the enclosure, but to "dissipate energy", "drain" and "dress" the expansive soil, and then stabilize the topsoil with broadleaf vegetation. 1995, he and his colleagues tried to adopt this technology on Chu-Da Expressway in Yunnan, with little effect.
In 2002, one of the major scientific and technological projects in the construction of the western region of the Ministry of Communications-"Study on complete sets of technologies for highway construction in expansive soil areas" was invited for national bidding, and Zheng Jianlong, which had already carried out research on highway expansive soil 10, won the bid in one fell swoop.
In the following years, Zheng Jianlong, in conjunction with many construction units, made an in-depth study on the properties of highway expansive soil and its treatment methods. In order to study the interaction mechanism between expansive soil and geosynthetics, Zheng Jianlong demonstrated it with members of the research group for dozens of times, and repeatedly discussed it with equipment manufacturers for 10 times, and finally developed the largest and best-performing CNC drawing test system in China. In order to truly evaluate the road performance of expansive soil filler, the research group revised the equipment scheme for many times 10, and successfully invented the improved CBR test device and its test method. In order to prove the feasibility of directly using expansive soil as embankment filler, he not only carried out a large number of indoor tests, but also personally led the members of the research group to the construction site for countless times to collect data, regardless of cold and heat, and followed it day and night for many years.
New technology is very important in application. Road maintenance is the responsibility system of the project manager, with strict budget and time regulations. What about the "cancer" that used to cost a lot of money and time to overcome? The reporter saw in the laboratory that apart from making drains inside and planting broad-leaved vegetation outside, the most important thing is that Zheng Jianlong has put on a "dress" that can change and expand with the climate change-a special plastic grille. Every 50 cm thick expansive soil, wearing such a special dress is like a thin and fat person wearing an elastic sweater. In this way, no matter what the weather is like, the expansive soil will not collapse because of the excessive "fat and thin" range.
For highway backfill, that is, the landfill of expansive soil, Zheng Jianlong and his colleagues adopted another method: "wrapping method", that is, wrapping expansive soil with other soil and putting on a coat of "heat preservation and seepage prevention", which is "impeccable".
Scientific exploration has been diligently pursued, and collective research has finally succeeded.
The reporter learned that this new technology has been widely used in 23 expressways in 10 provinces and regions and the South-to-North Water Transfer Project, which has strongly supported major project construction, created direct economic benefits of 1 65438+75 million yuan, saved construction land of 16202.5 mu, and reduced fuel consumption by 36.406 million liters. As a result, the research group has derived 12 national patents, 4 industry specifications, 3 monographs and 2 13 papers, and constructed a complete set of technology for highway construction in expansive soil area, which integrates theory, method, survey, design and construction technology, and makes the highway construction in China change from being afraid of expansive soil and avoiding expansive soil to fully mastering and utilizing expansive soil, and from frequent geological disasters and frequent use of expansive soil.
"No big project can be attributed to one person." In the interview, Zheng Jianlong, who has been engaged in highway construction research for more than 30 years, repeatedly emphasized this point. He told us a few things: Professor Yang Heping, as the technical director of the project, has been stationed in the front line of construction for many years. From June 2003 to July 2004, in order to ensure the construction quality of the experimental section, Professor Yang and Associate Professor Liu Longwu led two students to live in Nanyou Road, Guangxi for one year, only for postgraduate defense and school affairs, and returned to Changsha several times. Professor Yang lives with graduate students and goes out early and returns late together. When he instructed the construction personnel to reinforce the expansive soil embankment at the scene, he saw that the geogrid laying method of migrant workers was wrong. He demonstrated by himself, taught by hand, went back to school and plunged into the laboratory to study the test data. It is precisely because of this spirit of hard work that Professor Yang has published more than 70 project research papers, of which nearly 20 have been included by SCI, EI and others.
Wei, an associate professor in charge of physical engineering construction and numerical simulation calculation, lost 20 pounds in one year during his stay in Guangxi South Oil Road. There is also Dr. Aring Zhang, who was born in 1980s. He chose this subject when he was studying for a master's degree, and has been experimenting around this subject for five years since then. In an interview with reporters, he also led the graduate students to do experiments to find the "Sixth Ring Road in Southwest Beijing" project team of the research group, and watched him and the graduate students shovel dirt. The reporter lamented: Where is this doctor? It is clearly a group of migrant workers!
"By 2020, China will add tens of thousands of kilometers of expressways and millions of kilometers of ordinary highways. The treatment of expansive soil has extremely broad application prospects. "
This may be the driving force of Zheng Jianlong.