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Problems and Difficulties Existing in the Promotion of Steel Structure Housing in my country

We believe that the problems and difficulties in the promotion of steel structure housing in my country are mainly in the following aspects: (1) The degree of industrialization of supporting parts is low. Steel structure housing is a complex integration of technology, parts and materials. It is the discovery direction and inevitable product of the gradual modernization of the housing industry. Therefore, steel structure housing must first be industrialized. However, at present, the technically mature parts and accessories related to steel structure houses are either lacking, or have a low degree of industrialization, or lack technical standards or are inconsistent with the relevant standards of steel structure houses, especially walls, floors, balconies, stairs, etc., wet work More, resulting in the current steel-structured houses are basically in the embarrassing situation of "wearing a T-shirt and a tie". (2) The lack of modularization seriously restricts the industrialization development of steel structure housing. At present, there are only modular standards for stairs, doors and windows, kitchens and bathrooms, and there is still a lack of unified modular standards for most parts and components such as roofs, partitions, and elevators. (3) Steel structure design optimization, such as building plane and column network optimization, cold-formed rectangular tube instead of welded box column, variable section column application, buckling restraint support application, etc., reduce engineering costs and improve steel structure housing economy. 3.1 For the current various structural systems, their scope of application has not been clearly specified, and there is no design reference basis. Therefore, the current structure selection can only be based on the mechanical performance of the structure, with the goal of reducing the amount of steel used, and meeting the constraints of architectural design to obtain qualitative conclusions. In the structural design, the project cost can be effectively reduced by optimizing the design. This process is cumbersome and complicated, and the structure and the building need to be coordinated. At present, this work still has a long way to go. 3.2 The research on new beam-column joints can further reduce the cost of manufacture and transportation. In the national architectural standard design atlas "Steel Structure House (2)" (05J910-2), only 7 kinds of common beam-column joints are given, the new type of diaphragm through joints, sleeve-type reinforced joints, external ribs Ring plate nodes, etc. are not listed. In addition, in terms of the force transmission characteristics of the joints, the selection of joint forms (rigid, semi-rigid, hinged) should also be combined with actual calculation and comparison, and the optimal joint form can be selected, which can further reduce the amount of steel used, but the current specifications (such as GB50017- 2003) has a lot of lag and lacks the criterion for rigid, semi-rigid and hinged joints and the calculation basis for semi-rigid joints. (4) The lack of design specifications has led to some new high-quality steels not being promoted or problems such as inferior use of high-quality materials. For example, the current "Code for Design of Steel Structures" (GB50017-2003) and "Technical Specifications for Steel Structures of High-rise Civil Buildings" (JGJ99-98) do not list high-rise steel and weathering steel as recommended materials, nor give corresponding instructions, so that in the This type of steel cannot be used in the design or the strength of high-quality Q345GJ steel is taken as the value of ordinary Q345 steel. (5) Corrosion problems. The current "Code for Design of Steel Structure" (GB50017-2003), "Code for Design of Industrial Building Anti-corrosion" (GB50046-2008), "Code for Acceptance of Steel Structure Construction Quality" (GB50205-2001), etc. The design life is clearly stipulated. Even the newly published "Code for Design of Steel Structure Residential Buildings" (CECS261-2009) only makes general provisions on the number and thickness of anti-corrosion coatings, and its anti-corrosion effect and maintenance cycle lack clear standards. Require. In addition, since most of the steel components of the steel structure house are hidden in the wall, its anti-corrosion coating maintenance is very difficult, the maintenance is difficult, and the cost is high. At present, the regular inspection and maintenance requirements usually mentioned in the design description are vague and difficult to achieve. . (6) Application of high-strength steel. The third paragraph of 3.9.2 of "Code for Seismic Design" (GB50011-2010) puts forward clear requirements on the material properties of steel for steel structures: "The yield ratio of steel should not be greater than 0.85; the steel should have obvious yield steps, and the extension The length should not be less than 20%; the steel should have good weldability and qualified impact tou

Advantages of steel structures

Earthquake resistance: The roofs of low-rise villas are mostly sloping roofs, so the roof structure basically adopts a triangular roof truss system made of cold-formed steel components. A solid "slab-rib structural system", this structural system has a stronger ability to resist earthquakes and horizontal loads, and is suitable for areas with a seismic intensity of more than 8 degrees. Wind resistance: The steel structure building is light in weight, high in strength, good in overall rigidity and strong in deformation ability. The weight of the building is only one-fifth of that of the brick-concrete structure, and it can resist a hurricane of 70 meters per second, so that life and property can be effectively protected. Durability: The light steel structure residential structure is all composed of cold-formed thin-walled steel components, and the steel frame is made of super anti-corrosion high-strength cold-rolled galvanized sheet, which effectively avoids the influence of corrosion of the steel plate during construction and use, and increases the durability of light steel components. service life. The structural life can be up to 100 years. Thermal insulation: The thermal insulation material used is mainly glass fiber cotton, which has a good thermal insulation effect. The use of thermal insulation boards for external walls can effectively avoid the "cold bridge" phenomenon of the walls and achieve better thermal insulation effects. The thermal resistance of R15 insulation cotton with a thickness of about 100mm can be equivalent to a brick wall with a thickness of 1m. Sound insulation: The sound insulation effect is an important indicator for evaluating a residence. The windows installed in the light steel system are all made of insulating glass, which has a good sound insulation effect, and the sound insulation is more than 40 decibels. The effect can be as high as 60 decibels. Health: dry construction, reduce environmental pollution caused by waste, 100% of steel structure materials can be recycled, and most of other supporting materials can also be recycled, in line with current environmental awareness; all materials are green building materials, meet the requirements of ecological environment, good for health. Comfort: The light steel wall adopts a high-efficiency energy-saving system, which has a breathing function and can adjust the dry humidity of the indoor air; the roof has a ventilation function, which can form a flowing air space above the house to ensure the ventilation and heat dissipation needs of the roof. Fast: all dry work construction, not affected by environmental seasons. For a building of about 300 square meters, only 5 workers and 30 working days can complete the whole process from foundation to decoration. Environmental protection: materials can be 100% recycled, truly green and pollution

Design and technical performance of migrating modern steel structure buildings

The key to the success of the design of the steel structure building design is the technical conception and performance. In the deepening of the scheme design, it is necessary to cooperate closely with the structural engineer, the equipment engineer, and even the mechanical engineer. At this time, technical performance is a natural thing. Whether it is spatial form, formal volume or structural nodes, it is very important to influence its architectural design and performance. The following will illustrate this point from several aspects. (A) Technical performance of steel structure architectural design The conception of architectural image is a creative process of conceptual image, which is one of the difficulties in architectural creation and one of the core issues that have received much attention in architectural design. Looking back at the development of the relationship between architecture and science and technology since the Industrial Revolution, we can clearly find the hysteresis of architecture's response to technological change, which reflects the deep status of architecture in social culture and the relationship between architecture and people's way of life. close relationship. In addition, the emerging information revolution in modern times is widely permeating and involving every field of social activities, so that modern scientific thinking is integrated into architectural design, and great changes have taken place in the planning, architectural and landscape design methods of new projects. The purpose of architectural design has also developed from the pure pursuit of beauty to the pursuit of reasonable solutions to problems, which has fundamentally changed people's previous understanding and design methods of architecture, and finally affected the traditional architectural views formed by human beings for thousands of years, such as high Jipai architecture is its main representative, which embodies superb skills with exquisite nodes and fine processing, and designs and "manufactures" buildings with a higher level of craftsmanship. (B) The detailed design of steel structure buildings has higher requirements. The higher the complexity and refinement requirements of steel structure building design, the higher the requirements for detailed design. Because detailing determines whether a place is finally confirmed and its quality. In modern steel structure buildings, various metal structural rods and the details of the nodes connecting the metal rods are often exposed, giving the building a strong sense of technology, such as the Pompidou Art and Culture Center in Paris, France, built in 1977. , its steel columns, steel beams, trusses and other structural components are exposed, which not only reflects the beauty of technology, but also reflects the wisdom and ability of people. Therefore, it is very important for steel structure buildings to maintain high design requirements for detail quality, and special attention should be paid to steel structure buildings. (C) Architectural planning is also an influencing factor for the design and performance of steel structure buildings. Because steel structure building design has the general attributes of architectural design, architects do not design at will, and the owner's design task book affects the architect's plane and design concept. The effect is significant. Clients expect better performance from designers, and they expect designers and market experts to be more productively involved in the decision-making process of their final product. At this stage, the construction project emphasizes the overall design and the coordination between professional designers, market experts and developers. The design process includes continuous exchange and integration of information and knowledge. In addition, the specialization of steel structure buildings can not only provide a wealth of design knowledge, but also effectively integrate design resources and market experts to be jointly responsible for the building, so that the design and the owner's business intentions can be effectively combined to make the project profitable and reduce risks. Architectural characteristics of modern steel structures (1) High degree of pre-engineering, reduced construction costs, and shortened construction period It has certain versatility and interchangeability with building components of different manufacturing methods. At the same time, the pre-engineering of steel structure buildings integrates material processing and installation, which greatly reduces the construction cost; and accelerates the construction speed, so that the construction period can be shortened by more than 40%, thereby speeding up the capital turnover speed of real estate developers and making the construction energy efficient. put into use earlier. 　　 (2) Steel structure buildings can meet the requirements of super height and super span. The steel structure is uniform, close to the isotropic homogeneou

What are the components of a single-storey steel structure workshop?

A single-storey steel structure workshop is generally a space system composed of roof structures, columns, crane beams, brake beams (or brake trusses), various supports, and wall frames. These components can be divided into the following categories according to their functions: (1) The transverse frame is composed of columns and the roof trusses or roof beams supported by it. It is the main load-bearing system of the single-storey steel structure workshop. Snow loads and vertical and lateral loads from cranes and transfer these loads to the foundation. (2) Roof structure The structural system that bears the roof load, including beams, brackets, intermediate roof trusses, skylight frames, purlins, etc. of the transverse frame. (3) The support system includes the support of the roof part and the inter-column support. On the one hand, it forms the longitudinal frame of the single-storey steel structure workshop with columns and crane beams, and bears the longitudinal horizontal load; on the other hand, the main load-bearing system is The individual plane structures are connected to form the overall structure of the space, thereby ensuring the rigidity and stability necessary for the steel structure of the single-storey factory building. (4) The crane beam and brake beam (or brake truss) mainly bear the vertical and horizontal loads of the crane, and transmit these loads to the transverse frame and the longitudinal frame. (5) The wall frame bears the self-weight and wind load of the wall. In addition, there are some secondary components such as ladders, walkways, doors and windows, etc. In some single-storey workshop steel structures, there is also a working platform due to the requirements of process operation. 1. Column grid layout Column grid layout (layout of column rows) is to determine the arrangement of the load-bearing columns of the single-storey steel structure workshop on the plane, that is, to determine the grid formed by their longitudinal and lateral positioning axes. The span of the single-story factory building steel structure is the dimension between the longitudinal positioning axes of the columns, and the column spacing of the single-story factory building steel structure is the size of the columns between the lateral positioning axes. 2. Temperature expansion joints Temperature changes will cause structural deformation, resulting in thermal stress on the steel structure of the workshop. Therefore, when the plane size of the factory building is large, in order to avoid excessive temperature deformation and temperature stress, temperature expansion joints should be set up in the horizontal and vertical directions of the steel structure of the factory building. The arrangement of thermal expansion joints depends on the longitudinal and transverse lengths of the steel structure. When the temperature of a factory building with a very long longitudinal direction changes, the extent of expansion and contraction of the longitudinal members is large, which causes the deformation of the entire structure, generates a large temperature stress in the members, and may lead to the damage of the wall and roof. In order to avoid such adverse consequences, transverse temperature expansion joints are often used to divide the single-storey steel structure factory building into temperature sections that do not affect each other during expansion and contraction.  Google 主页

Development history of steel structure

Although China had outstanding achievements in iron structures in the early days, due to the constraints of the feudal system for more than 2,000 years, science was not developed, so it stayed at the level of iron buildings for a long time. It was not until the end of the 19th century that my country began to adopt modern steel structures. After the founding of New China, the application of steel structures has been greatly developed, far exceeding the past in terms of quantity and quality. The floor of the light steel structure is composed of cold-formed thin-walled steel frame or composite beam, floor OSB structural plate, supports, connectors, etc. The materials used are oriented strand board, cement fiberboard, and plywood. Each square meter of these lightweight floors can bear a load of 316 to 365 kilograms. The number of steel structure buildings indicates the economic strength and economic development of a country or a region. After entering 2000, my country's national economy has grown significantly, its national strength has increased significantly, and its steel production has become a world power. Construction is gradually increasing in economically developed areas. Especially around 2008, under the impetus of the Olympic Games, there was a boom in steel structure buildings, and the strong market demand promoted the rapid development of steel structure buildings. A large number of steel structure venues, airports, stations and high-rise buildings were built. Among them, some Steel structure buildings have a world-class level in production and installation technology, such as the Olympic National Stadium and other buildings. After the Olympic Games, steel structure buildings have been popularized and developed continuously. Steel structures are widely used in buildings, railways, bridges and houses. There are tens of thousands of steel structure enterprises of various sizes, and the world's advanced steel structure processing equipment is basically complete, such as Multi-head multi-dimensional drilling machine, steel pipe multi-dimensional intersecting wire cutting machine, corrugated plate automatic welding machine tool, etc. And now the processing and production level of hundreds of steel structure enterprises has reached the world's advanced level, such as steel structure manufacturing super and first-class enterprises. In recent years, the annual steel output has reached more than 600 million tons, and the steel varieties can fully meet the needs of construction. Steel structure design specifications, steel structure material standards, steel structure engineering construction quality acceptance specifications, as well as various professional specifications and enterprise construction methods are basically complete. The downstream industry of steel structure has a greater traction and driving effect on the development of the steel structure industry, and their demand changes directly determine the future development of the industry. 1. The upstream industry of steel structure is the raw material supply industry such as steel The steel industry is the material basis for the development of the steel structure industry, and the technological progress of the steel industry has created favorable conditions for the application of steel structures. Some large enterprises in the domestic steel industry have started the research and development of steel varieties and technologies for building structures, and have successively developed high-strength steel and steel for fire resistance, weather resistance, seawater resistance, laminar tear resistance, and low temperature resistance, as well as H-beam, high Performance color-coated steel plates, cold-formed steels, etc., have laid a good application foundation for the development of the steel structure industry. 2. The impact of upstream and downstream on the industry The upstream of the steel structure is mainly the steel industry, and the price fluctuation of steel products directly affects the procurement cost of the industry. On the whole, the upstream industry is basically a competitive industry, producing various types of steel plates, steel pipes, section steels and other steel materials for steel structures. Among them, H-beams and medium and heavy plates are the most commonly used products in steel structure buildings. Industry Insights Research Data In 2011, the crude steel output reached 696 million tons, and the output was relatively saturated. The raw materials required for the production of steel structures could obtain a stable supply. The downstream industries have a greater traction and driving effect on the development of the steel structure industry, and their demand changes directly determine the future development of the industry. Due to its comprehensive advantages such as high strength, light weight, good seismic performance, high degree of industrialization, short construction period, strong plasticity, energy saving and environ