There are very few online reports about Professor Liu Hanlong, executive vice president of Chongqing University, whose low-key personality is the same as the object of his research: rock and soil.
Rock and soil are invisible underground. People are often attracted by ornate buildings and speeding high-speed rail, but little attention is paid to how scientists solve geotechnical problems below ground level.
Liu Hanlong, 59, who laughingly describes himself as an "underground worker", has been working in the field of geotechnical engineering for more than 30 years. In recent years, he has grasped the safety of underground engineering and the development and utilization of underground space on the other, and led the team to promote scientific research and engineering application at the same time, providing a solid guarantee for the safety of China's infrastructure construction.
On November 22, Liu Hanlong was elected as an academician of the Chinese Academy of Engineering.
In the face of this honor, Liu Hanlong is very indifferent, and he is more concerned about scientific research work: "Chongqing has many people and little land, and the development potential of underground space is huge, and I still have many ideas to turn them into reality one by one on the land of Chongqing." ”
"A sense of accomplishment and satisfaction in solving engineering problems".
Wearing a straight coat and a gentle smile on his face, on December 7, the reporter met Liu Hanlong in a hurry in the geotechnical laboratory building of Chongqing University.
Talking about why he chose to major in geotechnical engineering, Liu Hanlong bluntly said that it was an "accident".
When he was in middle school, because he was good at physics and mathematics, Liu Hanlong liked radio and computers, but when he applied for university in 1982, he was transferred to major in water conservancy and hydropower engineering.
In the first decade of the 20th century, China's infrastructure construction entered a stage of rapid development, which required a large number of engineering and technical personnel. During his master's degree, Liu Hanlong took the initiative to choose the major of engineering geology and began to study and solve underground problems. After graduating from graduate school, he went to the design institute and began to design industrial and civil buildings for three years. Liu Hanlong recalled.
When he was a doctoral student, Liu Hanlong chose to major in geotechnical engineering, which has a wider research scope, and began to work with geotechnical engineering to study the safety of underground engineering and the development and utilization of underground space. Later, he went to Japan to study for a postdoctoral degree, and engaged in geotechnical engineering research.
If I want to draw a portrait of myself, it can be said that I have basically learned all the directions of the entire civil engineering, from the ground (structure) to the underground (geotechnical), from dry (building) to wet (water conservancy), from static to dynamic (**), and I have learned all Xi. Liu Hanlong said, "A project will involve many problems, which requires multidisciplinary joint research, and I think mastering different professional knowledge is conducive to personal growth and timely solution of engineering problems." ”
Even though he has a wide range of knowledge, Liu Hanlong still determines his main direction of attack as the most difficult geotechnical engineering, because this is the foundation of a building and a project, "if the foundation is not strong, the ground will shake the mountains". In the large-scale construction of major projects such as highways and high-speed railways, he quickly experienced the sense of accomplishment and satisfaction brought by solving engineering problems.
In 2006, during the construction of the Ningbo-Taizhou-Wenzhou Railway, due to the large number of high-voltage power lines above the station, conventional construction machinery could not enter, and the foundation could not be reinforced. The task of solving this engineering problem fell on Liu Hanlong.
At the invitation of the Fourth Design Institute of China Railway, Liu Hanlong led the team to the construction site. In order not to delay the progress of the project, the construction party asked them to develop a new foundation reinforcement technology in the shortest possible time.
We must quickly organize research and development, research and development equipment, technology, etc., not only to ensure the height limit of construction machinery, but also to ensure that the equipment can be driven underground to a depth of 30-40 meters to make pile foundations. Liu Hanlong said.
Liu Hanlong led the team to do a lot of experiments, analysis, formula and mechanical design, after a month of research, developed a new type of pile foundation technology: the use of small drilling rigs according to the design diameter, segmented drilling to the design depth into a hole, put into the segmented grouting pipe and then put the stone, after the completion of the grouting and consolidation into the pile.
Compared with other pile types, the construction machinery height of the slurry solid gravel pile is low, and the strength of the pile is also very high. Liu Hanlong said.
The solution of engineering problems does not mean the end of scientific research, and after going back, Liu Hanlong also compiled the standard of slurry solid stone pile technology. At present, this technology has been applied in projects such as Beijing-Shanghai high-speed railway, Shanghai-Nanjing intercity railway, Shanghe-Hangzhou high-speed railway, and Zhejiang-Hangzhou-Qianqian expressway, specifically to solve the problem of foundation reinforcement in complex construction environments.
Being able to solve engineering problems is the most important sense of accomplishment and satisfaction in my scientific research work, because the technology we develop has been applied in major projects, and I continue to motivate myself by constantly solving problems. Liu Hanlong said.
Solve the problems of settlement control and complex construction environment after the construction of weak foundations of major national projects such as highways and high-speed railways, solve the problems of low strength, high moisture content and high compressibility of ultra-soft silt foundations in China's blowing and reclamation (island) projects, and solve the problems of liquefaction and deformation of the foundation caused by liquefaction and ......liquefactionWith the solution of one major engineering problem after another, Liu Hanlong is also moving forward in the direction of deeper, broader and newer research.
"Starting from the demand, solve the problem of 'stuck neck'".
Microorganisms + rock and soil", two completely different things, but in Liu Hanlong's eyes, they are inextricably linked, "a series of biochemical reactions that occur in the growth and reproduction of microorganisms and metabolic activities can induce calcium carbonate deposition, so as to strengthen rock and soil".
In recent years, as global problems such as greenhouse effect and soil pollution have become increasingly severe, countries around the world have begun to advocate the use of green materials, and environmental factors have gradually occupied an important position in civil construction.
Most of the geotechnical reinforcement methods are chemical grouting, using chemical materials such as sodium silicate and cement, which are seriously polluted.
When we innovate, we don't do it behind closed doors in the laboratory, we must first understand social needs and engineering needs. In the interview, Liu Hanlong emphasized the word "demand" the most. It is precisely based on this that after coming to Chongqing University in 2013, he led the team to carry out research on microbial geotechnical reinforcement.
In 2014, Xiao Yang graduated from Hohai University with a Ph.D. and followed in the footsteps of his supervisor Liu Hanlong to Chongqing University and became a member of the research team.
When he first arrived at Chongqing University, Xiao Yang couldn't help but be dumbfounded - in the laboratory, there were almost no instruments and equipment for microbial experiments, only a few very dilapidated teaching instruments.
It was under such conditions that Liu Hanlong and his team started the research on microbial geotechnical reinforcement.
At that time, in the country and even the world, microbial geotechnical reinforcement was an emerging frontier topic, and only Tsinghua University in China had done relevant research, but the amount was very small. Therefore, the problem in front of Liu Hanlong's team is not only the lack of experimental equipment, but also the exploration of research paths.
Combining the relevant knowledge of different disciplines, adopting a variety of research methods, and carrying out close cross-disciplinary cooperation. Xiao Yang said that none of them are professional in microorganisms, and they need to learn about microorganisms by themselves, do a good job in the cultivation and domestication of microorganisms, and domesticate microorganisms into "occupational strains" that can induce the production of calcium carbonate.
The cultivation and domestication of microorganisms is not easy to do, it often takes more than half a year, failure is a common thing, and this is only the first step of this research, the follow-up to study the mineralization process, mechanical experiments and engineering application experiments.
After 4 years of accumulation and precipitation, in 2018, Liu Hanlong's team gradually had research results, published the world's first academic monograph in the field of microbial geotechnical "Principles and Applications of Microbial Soil Mechanics", and founded the world's first English journal in the field of biological geotechnical biotechnics (Chinese title "Biogeotechnical Technology"), and its scientific research capabilities ranked among the top in the world.
Nowadays, this technology is not only applied to the construction of islands and reefs to achieve the purpose of strengthening the "muscles and bones", but also used in the restoration of important cultural relics such as Dazu rock carvings, Ruijin Hongjing Monument, and the restoration of the Three Gorges Reservoir area. "It's truly pollution-free and sustainable. Liu Hanlong said.
There are too many uncertainties in underground space, and many questions cannot be answered in norms and books, prompting researchers to continue to innovate. In recent years, Liu Hanlong has not only made significant achievements in the research direction of microbial geotechnical reinforcement, but also made significant progress in new research directions such as the development of energy underground structure technology, the development of transparent soil test equipment, and the development of intelligent underground space.
"There is no such thing as a perfect individual, but there is a perfect team".
In 2020, after graduating from the Hong Kong University of Science and Technology, Wu Huanran, a doctoral student, did not return to his hometown for development, but chose to come to Chongqing.
When I chose Chongqing, I took a fancy to Mr. Liu and his team. Wu Huanran said, "The development momentum of this team is relatively good, and the development direction is very consistent with my research direction, which is very helpful for me to carry out scientific research." ”
After staying in Liu Hanlong's team for more than 3 years, Wu Huanran felt the cohesion and vitality of the team, and also felt Liu Hanlong's full support for young scientific researchers, creating a promising development environment for everyone.
There are relatively few resources and opportunities for young researchers, but Mr. Liu cares about everyone's growth, for example, when each of us applies for a scientific research project, he will always follow up and repeatedly revise the application materials for us. Wu Huanran said.
Under the influence of this environment and atmosphere, Wu Huanran is full of enthusiasm and has developed smoothly: he was rated as an associate researcher in 2022, and joined the associate professor as a postdoctoral fellow in 2023, and was only 33 years old when he became an associate professor.
In the process of growing up, young scientific researchers are prone to encounter all kinds of difficulties, Liu Hanlong knows this very well, he often emphasized: "It is not terrible to encounter difficulties, what is terrible is not to say when encountering difficulties, and when you feel resistance, you must talk about it in time, and we will find ways to help you solve it." ”
To this end, Liu Hanlong has set up a working mechanism and requires young lecturers to report to him every half a month, just to keep abreast of everyone's scientific research progress.
When Wang Chunyan, a young lecturer, was a doctoral student, she encountered a research bottleneck, which could only be solved through centrifuge experiments, but this experiment had to be done in other schools, which was very expensive. After learning about it, Professor Ding Xuanming of the team reported the situation to Liu Hanlong in a timely manner, and finally used the team's scientific research funds to help Wang Chunyan solve this problem, so that she could continue to promote the next research work.
Mr. Liu's team is very supportive of students' scientific research, and never stingy with funds and resources, so we can do what we want to do in a down-to-earth manner. Wang Chunyan said.
Liu Hanlong has always believed that there is no perfect individual, but there is a perfect team. Over the years, he has cultivated more than 10 national-level talents, and the whole team has grown from a few people to nearly 200 people including postdoctoral, doctoral and master's students.
During the interview, the reporter couldn't help but wonder: "Are we a perfect team now?"”
I don't think I'm perfect enough, but my team must be perfect. Liu Hanlong said.
"It's not enough to work 8 hours a day".
On December 18, 2013, Liu Hanlong came to Chongqing University from Hohai University. Nearly half a hundred years old, from the life, study, Xi, and work of Jiangnan came to the mountain city of Chongqing in order to make more breakthroughs in the field of geotechnical engineering.
There are still a few days to go and 10 years.
In the past 10 years, Liu Hanlong has led the team to "sharpen a sword for ten years" and undertaken a number of national and Chongqing science and technology projects, providing important technical support for the national and Chongqing geotechnical engineering design application and industry development.
These achievements were obtained by Liu Hanlong and his team with ten years of hard work.
Liu Hanlong believes that it is not enough to work 8 hours a day, and to achieve more results, it is necessary to spend more time and energy than others.
Due to the very busy administrative work and scientific research work, Liu Hanlong rarely rests even on holidays, even during the Spring Festival, he only rests for two or three days, and spends most of his time planning the development of the team, caring about the progress of the project, discussing the difficulties encountered in research, and revising the students' graduation and academics. As long as he is not on a business trip, on weekends and evenings, the last light in the office building must be his office.
Tang Xiaoxiang has been a secretary in the team for 7 years, and he has long been Xi to Liu Hanlong's working state.
Once, Liu Hanlong went to other places to hold an academic conference in the morning, and the plane returned to Chongqing that night, and it was already two o'clock in the morning. After getting in the car, Liu Hanlong finished combing through the day's work, and then said to Tang Xiaoxiang: "The car doesn't need to drive too fast, I can take a break." ”
When taking the first tool, Liu Hanlong usually works, and he rarely shows fatigue in front of outsiders, which is the most impressive time for Tang Xiaoxiang.
Mr. Liu rarely talks about the hard work and pressure, but these are expressed through the body, I remember that when I first came to the team, he still had black hair, and now he is more than half white. Tang Xiaoxiang said.
This state of hard work deeply infects everyone in the team.
We are working on the underground, but the whole team is constantly climbing upward, and everyone is working hard for the development of the team in their respective positions. Tang Xiaoxiang said.
Tang Xiaoxiang sometimes saw the lights on in the laboratory in the early hours of the morning, that is, the graduate students were still doing experiments, and no one asked them to work overtime, but they wanted to hurry up and complete the scientific research task in hand, and then do the next one.
The microbial geotechnical experiment team did every experiment from six or seven o'clock in the morning to the early morning of the next day, because the bacteria have been growing, everyone did not want to stop, hoping to get the most accurate experimental data.
Liu Hanlong hopes that the team members can set lofty goals and keep moving forward, and he will urge everyone to expand new research directions and think of new ways to solve new problems from time to time. At a year-end academic conference, he once said affectionately: "Why do people feel tired of walking uphill, it is because you are moving towards a higher goal, if you stop because you are too tired, while others are moving forward, you are going backwards when you stand still!."”
Although this team is already very well-known in the industry, Liu Hanlong still hopes that on the road of scientific research, everyone will not slacken, let alone stop moving forward.