Install ＂isolation pads＂ on buildings to resist earthquake hazards
Photo courtesy of vision china
1.54 billion yuan
In addition to ancient buildings and transportation infrastructure, the project achievements have been applied to many other livelihood projects, such as the isolation and reinforcement projects of important buildings such as primary and secondary schools and hospitals, and the construction projects of high-rise isolation residential areas. There are more than 60 projects of various categories, with a total construction area of about 3.36 million square meters and direct economic benefits of 1.54 billion yuan.
Key words of "people’s livelihood" in science and technology awards ③
2021 is the 45th anniversary of the Tangshan earthquake. In the past half century, in order to cope with the challenges caused by the earthquake and ensure the safety of people’s lives and property, the scientific and industrial circles have made great efforts. Since 1990s, isolation has gradually become one of the important concepts in the field of disaster reduction and resistance.
At the 2020 National Science and Technology Awards Conference held a few days ago, the project "Key Technology and Engineering Application of High Performance Isolation Building Series" won the second prize of the National Science and Technology Progress Award. The project was jointly completed by Beijing University of Civil Engineering and Architecture, Southeast University, China Institute of Building Science, Beijing Institute of Architectural Design and Research, China Institute of Building Standards Design and Research, Beijing Infrastructure Investment Co., Ltd. and Jiangsu Hongji New Energy Saving Technology Co., Ltd. The appraisal by the expert committee shows that the achievements of the project have reached the international advanced level, among which the design method of high-performance isolation buildings and high-performance isolation devices have reached the international leading level. The results of the project have been applied to many major projects.
What is isolation, how to understand the "high performance" in the project, and which major livelihood projects have applied high performance isolation technology? The reporter of Science and Technology Daily contacted a number of relevant units and asked them to give professional answers to these questions.
The core feature of seismic isolation is "being flexible and being rigid"
"Isolation is like stepping on a building ‘ Roller skates ’ 。” At the exhibition of application technology achievements of disaster prevention, mitigation and relief held in July 2021, the staff from Zhen ‘an Technology, a manufacturer of seismic isolation, introduced the characteristics of seismic isolation technology to the reporter of Science and Technology Daily. "The traditional concept of building earthquake resistance is to play hardball, ‘ Make rigidity with rigidity ’ The main means is to increase the physical strength of the members, which will lead to stronger earthquake action of the superstructure. The core concept of seismic isolation technology is ‘ Take Roukegang ’ Isolation devices, such as rubber bearings and dampers, are installed between the foundation or substructure of the building and the superstructure to reduce the seismic energy input to the superstructure, which can reduce the seismic action to 1/4 to 1/8. "
The physical model demonstrated in the field shows that when an earthquake occurs, the superstructure with isolation device only moves in parallel with a relatively small amplitude, while the building without isolation technology shakes much more violently. "This is the basic principle of isolation." The staff introduced.
However, this simple model is not enough to present the complete connotation of isolation technology. In reality, the application of technology must deal with all kinds of complex needs and scenes, such as high-rise residential buildings, hospitals, subways and historical buildings, which all have different conditions and requirements for isolation technology. In the design and construction of isolated buildings, there have been four major problems in the world for a long time, such as lack of applicability of design theory, lack of systematicness of design technology, lack of efficiency of key devices and lack of standardization of quality control. Therefore, the project "Key Technology and Engineering Application of High Performance Isolation Building Series" came into being, aiming at solving a series of key problems about high performance isolation technology.
There are both theoretical breakthroughs and practical applications
In view of the four long-standing problems, the project has mainly realized four innovations, namely, the design theory of high-performance isolation structure, the multi-objective integrated design technology of isolation structure, a series of high-performance isolation devices with adjustable functions, and the quality control technology of isolation building construction, and edited a series of standards.
"Our project lasted for more than 20 years and produced a lot of results, with rich content." In an exclusive interview with Science and Technology Daily, Guo Tong, the second winner of the award-winning project and a professor at the School of Civil Engineering of Southeast University, explained that the project has published 166 papers, won 30 invention patents and published 5 works, and the results have been applied to more than 60 important projects.
"For example, we have developed a variety of high-performance isolation bearings, such as rubber bearings with ultra-low modulus and high damping, adjustable and low-frequency sensitive composite isolation bearings, and new tension-controllable isolation bearings. In addition to bearings, there are other devices, such as adjustable viscous dampers and large deformation flexible pipes, which are our achievements in device research and development. However, the project results are not only the device, but also the design theory, design technology and quality standards. " Guo Tong added.
As the second completion unit of the award-winning project, Southeast University took the lead in completing a number of project achievements, covering the main aspects of the above four innovations. In addition to innovation in design and theory, the project has many achievements in engineering application and promotion, and many of these achievements have already landed and become a part of people’s livelihood projects in daily life.
It has been widely used in people’s livelihood projects
"Add the bottom" to the ancient building and "add the cover" to the subway … … Among the application achievements of the project "Key Technology and Engineering Application of High Performance Isolation Building Series", there are many such "ingenious pens".
In 1933, at the initiative of Cai Yuanpei and others, the Humanities Museum of the National Central Museum was completed in Nanjing, which is today’s Nanjing Museum. With the help of seismic isolation technology, this 80-year-old national key cultural relics protection building has become more "young" — — With the advanced technologies such as integral lifting (3m) and seismic isolation and reinforcement, the seismic level of the building has been effectively improved, the appearance and features have not been damaged, and the internal space of the building has also been expanded, giving cultural protection units and visitors more margin. After the completion of the project, the Disaster Prevention Research Center of the Ministry of Housing and Urban-Rural Development included this reinforcement of Nanjing Museum as a classic case and also selected it as the cover of the published series.
In another famous historical and cultural city, Beijing, thousands of miles away, the achievements of isolation technology also show their talents. Compared with Nanjing, some natural and human conditions in Beijing are more complicated: being in an earthquake-prone area, earthquakes have been frequent since ancient times; It has the longest subway system in the world; There is a large population and the intensive land use of transportation hubs is tight. Seismic isolation technology plays a key role in the construction of high-performance buildings. In Beijing Metro Line 6 Kunyufu, Line 8 Park Yuefu and Line 16 Beian River Cover, the key technologies of complex high-rise isolation structures have been popularized and applied, with an application area of 890,000 square meters, which is the largest cover isolation building complex in the world at present.
In addition to the above-mentioned subway superstructure isolation building, there is also a major infrastructure project in Beijing that adopts the project results. According to the data provided by China Institute of Building Standards Design and Research, the fifth completion unit of the project, the national industry standard of Flexible Pipeline for Building Isolation edited by this unit has been applied to the high-performance isolation device of Beijing Daxing Airport. Daxing Airport, located on the southern extension line of Beijing’s central axis, is the largest single isolation building in the world at present. A total of 1,152 sets of isolation devices are used in the terminal building, and the rubber isolation bearings used are the highest in China, both in volume and tonnage of a single bearing.
A major feature of Daxing Airport is that different means of transportation can transfer at the same station, and the negative second floor of the terminal is used for high-speed rail, subway and intercity trains. The high-speed entry and exit of trains will produce strong vibration and large wind pressure, which is also one of the difficulties that isolation technology in China has overcome.
Guo Tong said that in addition to ancient buildings and transportation infrastructure, the results of the project are also applied to many other livelihood projects, such as the isolation and reinforcement projects of important buildings such as primary and secondary schools and hospitals, and the construction projects of high-rise isolation residential areas, such as the Tianyang Innovation City project in Yanjiao, Hebei Province, with a total area of about 1.14 million square meters, and the Xichang Territory project in Sichuan Province, which is located near the fault in the 9-degree zone (the earthquake amplification factor is 1.5). There are more than 60 projects of various categories, with a total construction area of about 3.36 million square meters and direct economic benefits of 1.54 billion yuan.
According to the data of Sichuan Seismological Bureau, as early as 2015, the total number of buildings applying isolation technology in China has exceeded 6,000, accounting for half of the world, more than 5,000 in Japan, ranking first in the world. The staff of Zhen ‘an Science and Technology said that at present, there are more than 10,000 buildings applying isolation technology in China.
Guo Tong commented that as an efficient means of structural earthquake prevention, isolation technology has broad application prospects in the future. Technicians are still developing various isolation devices with excellent performance and expanding their application scope, contributing to improving the city’s disaster prevention capability.
◎ Intern reporter Sun Mingyuan