A brief description of the structural system of the steel structure


Release time:

2021-09-15

Engineering foundation form: reinforced concrete independent column foundation or raft foundation is generally used. When there is a basement, the steel column can be directly extended to the basement, and the structural force transmission path is simple; the construction period of the structure is short, and the comprehensive cost is reduced.

1. Engineering foundation form: reinforced concrete independent column foundation or raft foundation is generally used. When there is a basement, the steel column can be directly extended to the basement, and the structural force transmission path is simple; the construction period of the structure is short, and the comprehensive cost is reduced.

2. Steel frame or frame-support structure system 1) Steel frame or frame-support: The steel structure system of steel structure houses mainly adopts concrete-filled steel tubular columns, light-weight H-beam frame system and H-beam T-shaped connection steel columns, light-weight H-beam frame systems The prefabricated steel frame sheet of the profile beam is a composite frame system assembled by steel beams on site. It is a multi-layer frame system type composed of two steel structures in both vertical and horizontal directions. CFST frame column steel frame. It is a composite compression member formed by pouring high-strength plain concrete into an empty steel tube. It uses the steel tube to restrain the concrete, so that the concrete in the steel tube is compressed in three directions, thereby improving the compressive strength and ductility of the concrete. At the same time, the concrete in the tube ensures the local stability of the steel tube. Therefore, the CFST column combines the advantages of the steel column and the concrete column. The axial bearing capacity of the single column is greatly improved, and the section of the frame column is greatly reduced. Compared with the H-shaped steel column, The steel consumption can be saved by about 50%, the construction cost can be reduced by about 45%, the diameter of the steel pipe is unchanged, and the wall thickness is gradually reduced; in addition, the concrete in the CFST column can absorb heat, slow down the heating rate of the steel column, and once the steel column Yielding, the concrete can withstand most of the axial load, preventing the structure from collapsing. The combined frame of the H-beam T-shaped connection steel column, that is, the steel structure adopts the factory prefabricated steel frame sheet (steel column, steel beam and support combination), and the on-site combination of the frame system is more advanced in technology. The processing method of merging vertical H-shaped columns has strong rigidity in both directions and no weak axis; the lateral rigidity is increased (with a certain support), and the overall structure has a good stress effect. The keel and door and window frames are assembled at the same time, and the frame pieces are connected by high-strength bolts and connecting plates on site. This allows the structural frame to be placed directly on site along with wall materials and doors and windows, speeding up construction. The steel structure frame beams are generally made of high-frequency welded H-beam. Its advantage is that the width and thickness of the flange plate can be arbitrarily changed according to the design requirements, and the thickness of the web can meet the conditions of local stability. The so-called I-beam) is thin, and the inertia moment of the member section is increased by 20~30% compared with the rolled H-beam, which is equivalent to saving 20~30% of the steel consumption for the frame beam that mainly bears the bending distance. In the comparison of rolled H-beams, due to the advantages of light weight, high strength, beautiful appearance, convenient processing, random size according to design requirements, and strong production capacity, it is more economical and reasonable, and has the characteristics of flexible section size selection. The connection between beams has two forms: rigid connection and hinged connection. Rigid connection refers to the connection form in which the web is connected by high-strength bolts and the upper and lower flanges are welded; hinged connection refers to the connection of high-strength bolts at the web, and the upper and lower flanges do not need to be welded. For the connection form, the former requires on-site welding, while the latter does not require on-site welding, and the installation is not limited by weather and season. Therefore, the installation procedure is greatly simplified, the on-site workload is greatly reduced, and the installation speed of the steel structure can be doubled. At the same time, this hinged joint can be used. In the design and calculation of steel beams, all steel-concrete composite beam sections are used for calculation. The steel beam is in tension and the cast-in-place concrete is under compression. It saves the amount of steel used for steel beams, reduces the height of steel beams, and increases the space for use. 2) The horizontal stress member of steel structure - floor slab and roof slab are divided into two types: prefabricated floor slab and cast-in-place floor slab. Due to factors such as earthquake resistance, easy cracking, and sound insulation, it is rarely used. At present, cast-in-place concrete floor slabs are used, which are divided into two forms: cast-in-place concrete on profiled steel plates (composite slab) and ordinary formwork cast-in-place concrete. The latter has more economic considerations, while the former is more suitable for steel structures. Features: ①The profiled steel plate is used as a formwork and replaces the steel bar under the floor; ②It meets the fire protection requirements; ③No need to support the formwork; Level the mortar (falling objects hurt people), which is conducive to the embodiment of the secondary decoration effect (paint, wallpaper or other).

3. Enclosure structure system The selection of enclosure wall materials suitable for the steel structure system is a very important factor restricting the development of steel structure housing. It requires: ① high degree of industrialization, easy to connect with steel structure, ② light material and high strength, ③ strong waterproof, impermeability, and frost resistance, ④ heat preservation, heat insulation, energy saving, ⑤ exterior finish, ⑥ fire resistance, ⑦ Durability, ⑧ easy acceptance of economic indicators, etc. my country's wall reform has been carried out for many years, but because the residential wall is greatly affected by various comprehensive factors, especially in the northern region, the requirements for thermal insulation and waterproof performance, safety performance, economic indicators, etc. are very high, although various materials (composite wall) body) a lot, but very few are really acceptable. Therefore, many developers have to adopt the most traditional form of hollow brick blocks, using locally produced lightweight aerated concrete blocks (700kg/m3), but always different from the characteristics of steel structure houses; for composite walls There are various forms of body, such as: ALC, Yitong lightweight wallboard; concrete board plus benzene board; block plus benzene board; DP membrane mesh, etc., these wall boards with mortar can also ensure the function of the wall. With the continuous development and improvement of my country's building materials industry, wall materials suitable for the region and for the production of steel structure houses will emerge in large numbers.

4. Under the condition that the fire protection of steel structures meets the requirements of the current fire protection regulations in my country, the fire protection of steel structures generally adopts two types: thick coating type and thin coating type (expansion type). The proportion is very large, which also hinders the smooth progress of the steel structure house. In the fire protection design of steel structures, we can still use flame-retardant wallboards and blocks (cladding) to carry out fire protection of steel structures. For example, the fireproof board is equipped with heat-resistant rock wool board and is fixed on the steel member by fasteners. This method is dry construction, not limited by climatic conditions, and integrates fire protection and decoration.

5. Corrosion of steel structure The corrosion of steel structure is closely related to the relative humidity of the air and the content of corrosive substances in the atmosphere. Usually the relative humidity is below 60%~70%, the atmospheric corrosion of steel is slight, and once the critical humidity (60%~70%) of steel corrosion is exceeded, the corrosion rate of steel will accelerate. Therefore, it is necessary to brush or spray anti-corrosion coatings on the surface of the steel structure. The primer in the fire retardant coating (primer and topcoat) should have good adhesion to the steel surface, strong adhesion between the topcoat and the primer, and match the effect, performance and hardness between the paint layers. Now mostly solvent-based inorganic zinc-rich primers are used. Because this primer has a long anti-rust life and can also withstand high temperatures of 5000C. Baosteel has developed weather-resistant refractory steel in the selection of steel materials for steel structures and fire-resistant and anti-corrosion materials, and has successively passed fire tests. If weather-resistant refractory steel can be used in steel structure houses, it will significantly reduce the cost of anti-corrosion and fire protection measures for steel structures. .

6. Steel structure construction is due to the standardization of frame nodes and components in steel structure design, that is, three-story beams for each column, and H-shaped steel beams for node corbels are designed into several standard components. The prefabrication of on-site construction of the structure has laid the foundation. Therefore, the steel structure installation can be installed on a single column, and the three beams can be connected in place; at the same time, the frame mesh can also be installed in the factory, and the construction method of the overall hoisting on site. For concrete-filled steel tubular columns, concrete can be poured in batches with three to four layers.


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