1 . The proportion of construction steel in the full total steel output?



in recent decades, the former Soviet Union, the United States and Japan have been the most effective three countries in the world in terms of steel output, with their steel output ranking first in the world subsequently. Therefore , the construction of steel structures in these countries is booming. In the same period, China's development in this region is relatively slow, and the amount is relatively backward. Lately, with the implementation and promotion of China's reform and opening up policy, China's economic construction has made rapid progress. During this time period, China's steel production has become the first in the world. In 1996, China's steel output exceeded 100 million tons for the first time; in 1998, China's steel output reached 114. 34 million tons, and an annual increase of 3 million tons. But at present, there was still a significant gap between China and developed countries in lots of aspects. Therefore , to be able to promote the further development and application of China's building steel structure, we have to know the effective use of foreign building steel structure.? br >


the amount of construction steel in China is the reason about 20% - 25% of the total steel output, whilst the developed countries account fully for significantly more than 30%. For example , in america and Japan, the index has exceeded 50%. In China, steel is principally used in building steel structures, steel bars for reinforced concrete, steel strands, steel wires, windows and doors, etc ., that only about 10% is employed for steel structures in ChinaOf the 100 million tons of steel output, 2-3 million tons are in reality used for steel structures.?


according to some data of the distribution of American metal construction industry in the exact middle of 1998, the development of American metal construction industry and the basic market In the 1950s, 1960s, 1970s, 1980s and 1990s, the annual sales volume in millions of US dollars / annual processing volume in thousands of tons were 150 / 30, 300 / 65, 1200 / 110, 1500 / 125 and 2200 / 190, respectively. Like in the 1950s, the corresponding growth multiples were 1 . 2/2, 2. 8/3, 7. 10/5, 7 and 15 / six. 3, respectively. It may be seen out of this that the annual sales level of construction metals in america is growing rapidly. Approximately the annual sales volume has exceeded 2. 5 billion US dollars and the annual processing volume has reached a lot more than 2 million tons.?


2. Steel structure and light steel structure of low-rise and multi-storey buildings?


the main market distribution of metal buildings in the United States: Industry (production plant, warehouse and auxiliary facilities, and so forth ), commerce (shopping malls, hotels, exhibition halls, hospitals, office buildings, and so on ), social areas (private and public community activity centers and buildings, such as for example schools, gymnasiums, libraries, etc . ), churches, etc . ) and comprehensive, accounting for 46%, 31%, 14% and 9% respectively.?



in the usa, steel structure continues to be quite typical in low-rise buildings. The American Institute of steel construction and the metal building Manufacturers Association (AISC and MBMA) jointly developed a design guide for low rise buildings. The alleged low rise buildings areIt refers to the industrial workshop, warehouse, office and other office and community buildings with a floor height of less than 18m and a floor quantity of only five. Among them, non residential buildings with two floors or less account fully for 70%.?



light steel buildings have been widely used in factories, warehouses, gymnasiums, exhibition halls, supermarkets and other buildings in certain developed countries. The alleged light steel identifies the colour steel plate whilst the roof and wall, thin-walled steel as purlin and ring beam, to weld the building steel structure.


3. High rise and super high-rise steel structure?


as a result of continuous improvement of human cultural life, the requirements for high-rise and long-span buildings are getting to be higher and higher. amjsteel The steel structure it self has the unique features of light weight, high strength and fast construction, therefore it is very ideal for high-rise and long-span, especially for super high-rise and super long-span. Currently, the best and largest structure in the world is steel structure, and the stadiums of previous Olympic Games are mostly steel structure. Currently, several pure steel structure buildings in the world would be the highest super high-rise buildings in the world. They truly are: the 102 story, 381m high Empire State Building in 1931 (the highest before 1969); the 110 story, 417m high World Trade Center in New York (two South and North) in 1969;?


the Sears Tower in Chicago, USA, with 110 floors and 443m tall, was built in 1970; and the KLCC, with 450m in height, was integrated 1996The world's tallest building, nevertheless the Sears Tower in the United States has objections);?



the Jinmao Tower in Shanghai, integrated 1997 in China, has 95 floors, 421m in height and 395m in structure, which also ranks among the best in the world. If Shanghai Pudong global financial center building (460m on 95th floor) is completed, it will likely be regarded as the greatest in the world, which is a great honor for China. Shenzhen Saige Plaza building, 70 floors, 279m high, is the highest super high-rise building in the world, which will be also an excellent honor for China.?



mega steel structure is a fresh system of high-rise or super high-rise buildings, which is produced to meet up the special or comprehensive functions. It has good building adaptability and potential high-efficiency structural performance, is a really developed structure. For instance , the NEC building with 43 floors and 180m saturated in Chiba County, Japan, comes with large openings and large space courtyards. Its mega structure is a huge space truss system made up of four Mega structural columns and four giant space truss beams. Through analysis, this type of system has quite strong anti push rigidity. Yet another example is the new commercial bank building built in 1997 in Frankfurt, Germany, that has 63 floors and 298. 74m high. Additionally it is the greatest super high-rise building in Europe. The plane of the building is an equilateral triangle with side length of 60m. Its structural system is three independent frame tubes with triangle vertices.


4. Large span steel structure?


large span or large span mostly adopt steel structure, obviously, it's also finished with "membrane", but inflatable membrane is rarely found in the past few years due to some shortcomingsThe tension membrane also needs the support of steel cable and steel pole.?


large span steel structure is trusted in multi-functional stadiums, convention and exhibition centers, exhibition halls, waiting halls, aircraft hangars, and so forth The earliest flat grid with the largest span was 91m × 122m (square pyramid) in the University of California gymnasium in La in the 1960s. The greatest double-layer latticed domes would be the Houston cosmodome (196m in diameter) and the brand new Orleans Superdome (207m in diameter), that have been also built in america in the 1970s. In the 90s, the biggest span single layer latticed shell in the world was built in Nagoya, Japan. The diameter of the building is 229. 6m, the diameter of the structure is 187. 2m, and the three direction grid is adopted. The greatest indoor fitness center in the world is the Atlanta fitness center, the primary Fitness center of the 1996 Olympic Games in the United States (the quasi elliptical plane, 186m × 235m), which will be consists of cable, pole and membrane. It is the most promising new space structure. Fukuoka fitness center built in Japan in 1993, with a diameter of 222m, is the largest open close steel structure roof today, as the skydo me integrated Canada in 1989 (with a diameter of 203m) has been reduced to the 2nd largest open close structure in the world. The roof structure in excess of 300m consists of steel plate and section steel, which is not the optimal scheme. Lately, the hybrid (hybrid) structure has been studied successfullyRod, cable and membrane are used together. The most typical example is the Millennium Dome at the turn of the millennium. It was integrated June 1997. It took just one year to create. In June 1998, the lifting ceremony occured. Located in Greenwich on the South Bank of the Thames River in London, the pavilion is the largest roof in the world. The dome is similar to a UFO with a diameter of 320m. The dome is suspended by 12 100m high mast columns (90m of the column itself), including 10m supports, with a total amount of 70km steel cable. The mast columns are arranged on the circumference of 200m in diameter. The dome grid consists of 72 pairs of radial cables and 7 circumferential cables. The dome is 50m high, with a central cable truss and 70m diameter ring at the center, covered with 144 pieces of double-layer large white fiberglass cloth coated with Teflon. The full total section of the project is 80000 m2, with an overall total budget of 758 million pounds. The exhibition will be held with the theme of "innovation era" to welcome the 21st century. There are 12 exhibition areas in the museum, including "human human anatomy exploration", "time class", "financial window", "earth miracle" and "looking forward to the future". Obviously, from a theoretical standpoint, you'll be able to realize the structure with the biggest span. Consequently , scholars and research institutions in Japan and the United States are all undertaking research. townhouse light steel construction For instance , in 1959 fuller proposed to build a 3. 22km-diameter short-range wire mesh shell, within the 23-59 block of New york, with a weight of 80000 T. the span of 200m and 500 proposed by Japan Pakistan Railway Group Institute wasM and 1000m reticulated shell blueprints, 500m for all-weather multi-functional sports and entertainment hall, 1000m for creating a perfect future city, reflecting the work, living and entertainment integration of rich day to day living environment. Though it remains to be further studied whether this assumption could be realized in reality, when it comes to bridges, the span of approximately 1000m has been realized. In the world, the biggest cable-stayed bridge is Japan's Duoluo bridge with a complete amount of 890m; the greatest suspension bridge is Japan's Mingshi bridge (1991m), and the biggest span bridge for both highway and railway is Qingma bridge (1377m) in Hong Kong, China. The first hyperbolic paraboloid suspension roof in the world may be the famous American Leili sports hall. amjsteel In addition , all previous Olympic Games and expositions can show the development degree of steel structure. For example , in 1972, Munich, Germany (cable net complex covering 74800 M2 Stadium), 1976, Montreal, Canada, 1980, Moscow, 1984, La, USA, 1988, Seoul, Korea (120m diameter gym and 93m diameter fencing hall are cable domes), 1992, Spain, Barcelona, San Jodi Stadium (128M), 1996, Atlanta, USA, Georgia Dome (186m × 235m cable dome). 2000 Sydney main stadium, Australia (110000 people, two 220m × 70m Hyperbolic Paraboloid Latticed Shells). Airport and hangar are long-span structures, and steel structures are basically utilized in the project. Like London Heathrow hangar (phase I and phase II) must certanly be of scaleThe bigger project. Recently, the administrative centre hangar (2-153m × 90m) built in our country adopts three-layer inclined pyramid grid and welded spherical joint plate grid, that has the largest span scale in the world, which can be yet another great honor in steel structure inside our country. The steel structure roof of the airport is more colorful as a result of the high requirements of the building. Both Hong Kong airport and Malaysia Airport in China adopt the proper execution of large-area single grid shell. At present, a type of three-dimensional truss system with wavy surface, tree support and directly intersecting joints is popular in the world and in China. It looks majestic and beautiful. Shenzhen airport, capital airport and Pudong airport are typical examples.


5. The chance and gap of China's construction steel structure?


from the ability of some developed countries in the United States, Japan and Europe, the construction industry will become the key market of steel application. Currently, there is still a gap between China and it. For that reason the high-rise building steel within our country has been imported from abroad up to now, especially the thick steel plate bigger than 50 mm. The z-direction performance of domestic products is still not up to the requirements. Foreign countries not only have large steel plate thickness, but can also meet various performance requirements. Like the 100mm thick steel plate that Japan has been able to make has the following types:



�? you will find 590n / mm2 (ht590) thick steel plates of high strength and low preheating type (previously preheated 75 �? now preheated 50 �?;



�? earthquake resistant thick steel plates, mainly of low yield ratio and high strength steel (ht590-ht780)）And low yield point steel plate, which can be mainly produced in Japan and utilized in secondary structures, when the earthquake occurs, the material yields first to make sure that the main structure reduces the earthquake loss;


�? fire-resistant thick steel plate. You will find 400N / mm2 and 490N / mm2, and the yield strength can reach 2 / 3 of normal temperature when it's 600 �?



�? austenitic stainless steel plate and ferritic stainless plate for decoration (coastal use, more advanced than the former). At the moment, virtually all domestic high-rise steel structures are imported from abroad, the overall contracting of the project is undertaken by foreign countries, and the manufacturing and installation are contracted by domestic low-cost labor. This example must be reversed quickly, since it is not commensurate with the status of China as a major steel country. Long span steel structure is not as prominent as high-rise steel structure, but design schemes (including buildings and structures) in many cases are won in foreign countries. This case is a long way away from the call of the central government to emphasize the establishment of our own scientific and technological innovation system, which should attract the interest of China's construction industry. It is worth our thinking whether the level is low or other reasons.


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