Since entering the 1990s, the development of steel structure buildings in China has been very rapid, especially the completion of some iconic high-rise buildings representing the city, which has opened a new page for the development of steel structures in China. For example, the 88th storey of Shanghai, the 420m high Jin Maoren 1 in the world, has been completed with a skin-supported axial compression column. The F component is the object of analysis. The external dimensions of the component are 160mmX50mmX20mmX2.75mm cold-formed thin-walled C-shaped channel steel. As shown, the material yield strength is Py = 270Mpa. It is assumed that the initial eccentricity of the load is 1/1000 of the geometric length of the component The length of the component is 3.60m, and the two ends are hinged. The profiled steel plate and the components are connected with self-tapping screws. When there is no connection between the profiled steel plates, the skin shear stiffness is QL, and when the load eccentricity ey = L / 1000, eZ = U1000, corresponding to different skin shear stiffness values ​​Q, the component is calculated The angle of the cross-section and the displacement of the shear center in the span can be seen from the figure. The change of the skin's shear stiffness does not make the angle of the cross-section of the member much different. This shows that the increase of the skin's shear stiffness cannot increase the restraining effect on the torsion of the member. However, the increase of the shearing rigidity of the skin can effectively reduce the lateral deformation of the member. It must be pointed out that the above result is the result obtained when the torsion constraint value F = 0 is not taken into account without considering the torsion constraint provided by the skin on the member. The F value is N * mm / (mmTad). However, in the actual structure, the skin can always provide different degrees of torsional restraint for the member. If this favorable factor is not taken into account, the calculation result will be overly conservative. Both the test and the calculation results show that the torsional restraint provided by the skin for the member The effect can effectively reduce the torsional deformation of the member, and significantly improve the stable bearing capacity of the axial compression member. The skin calculated by the theoretical calculation has an influence on the components. Its FL = 1437.2N.mm / (mm * rad) is determined by experiment.

The 2000 supplementary period of industrial architecture will be a period of rapid development of steel structures. For a long time, the pattern of domination of concrete structures and masonry structures will be broken. Engaged in steel structure manufacturing and construction: T companies have broad prospects, and various architectural design institutes are also facing With new opportunities and challenges. However, the following points still require attention from all parties.

1. The promotion of steel structure construction should be increased. At present, the competition in the steel structure industry is fierce. This competition comes only from various industries and companies, and more importantly from steel and reinforced concrete structures. In developed countries such as Japan, steel structure buildings account for more than 50% of the entire building, while China only accounts for less than 5%. The gap is far.

For the cost of 71 steel structure and concrete structure, there should be a comprehensive and comprehensive understanding. It cannot be considered that the cost of steel structure is more expensive than concrete, which excludes the f comparison plan. This is especially important for the majority of designers. In fact, the total project investment of a high-rise building, including project cost, relocation cost, land acquisition fee, etc., the project cost only accounts for 50% of the total project investment. The project cost also includes structural cost, decoration cost, equipment cost, etc. The cost only accounts for about 30% of the project cost. The structure cost is divided. Part structure and basic cost, part h structure cost only accounted for 50% and 70% of the base cost. Steel structure only refers to the superstructure of the project, accounting for less than 10% of the total project investment. Therefore, the difference between the steel structure and the concrete structure of high-rise buildings accounts for T: Cheng ’s total investment ratio will be smaller, generally less than 4% of the total investment of the project. If you consider the use of steel structure because of its light weight and foundation Low cost; because of its high strength, which can increase the effective area of ​​the building: fast construction speed and good seismic performance, many advantages, then the advantages of steel structure are self-evident.

2. Promotion and application of residential steel structures should mention important locations. Although the construction of steel structures is developing rapidly, it is still blank in the residential field. Tens of millions of square meters of residential buildings are built every year across the country, but few use steel structures. Of course, this has something to do with China's traditional ideas, concepts, and deviations in its understanding of steel structures. Fortunately, the Tianjin Municipal Government has taken the lead in deciding to start light-weight steel construction this year and will build a light-weight steel house of 100,000 m2. Its demonstration effect will not be underestimated. It is hoped that relevant functional departments and designers in various places should be ahead Consciousness, response, and due contribution to the development of light steel residential buildings.

3 The technical personnel of steel structure manufacturing, construction enterprises, design institutes, etc. should be actively improved: 1L service level In China, for a long period of time, due to the seldom use of steel structures, most of the juice institutes and construction enterprises are engaged in a single The design and construction of the structure of the concrete. At present, we should vigorously strengthen and improve the steel structure business level of technical personnel at all levels. All institutions of higher learning, academic groups, etc. should be given full play to hold steel structure technical lectures and standard training courses.

4 The development of steel structure should be supported by policy and inclined. Such policy support should include: in the development of steel structure technology, it should be included in the national construction technology development plan and focused support in scientific research projects, funding, etc .; Steel-structured residential buildings are given preferential treatment in terms of land acquisition and taxation to reduce construction costs and make them more competitive in the market: vigorously promote the use of domestic steel to form a virtuous circle with steel production enterprises.

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