Roof support system and roof design of steel structure plan workshopt
The layout of the roof support system shall be determined according to the plant span, height, column grid layout, roof structure form, crane tonnage and seismic fortification intensity of the area. Generally, roof structures with purlin or without purlin system shall be provided with vertical supports; In the purlin free system, the large roof panel has three points welded with the roof truss, which can play the role of upper chord support, but considering the limitations of construction conditions and installation needs. The roof with purlin or without purlin system shall be provided with top chord transverse support at the top chord of roof truss and roof truss. Longitudinal horizontal supports shall be provided for plants with roof truss spacing not less than 12M, or plants with extra heavy bridge cranes or plants with large vibration equipment.
Thermal insulation and fire prevention of steel
Steel has high thermal conductivity, with a thermal conductivity of 50W (M. ℃). When heated to more than 100 ℃, its tensile strength will decrease and its plasticity will increase; When the temperature reaches 250 ℃, the tensile strength of the steel will increase slightly, but the plasticity will decrease, resulting in blue brittleness; When the temperature reaches 500 ℃, the steel strength drops to a very low level, which will cause the steel structure to collapse. Therefore, when the ambient temperature of the steel structure reaches more than 150 ℃, the thermal insulation and fire protection design must be made.
Setting of temperature expansion joint
The temperature change will cause the deformation of the steel structure plant and cause the structure to generate temperature stress. When the plane scale of the plant is large, in order to avoid generating large temperature stress, temperature expansion joints should be set in the vertical and horizontal directions of the plant. The length of the section can be implemented according to the steel structure specification. Temperature expansion joints are generally treated by setting double columns. Rolling bearings can be set at roof truss supports for longitudinal temperature expansion joints.
Enough attention should be paid to the rust prevention of steel structure plant components, and corresponding countermeasures and measures should be taken in terms of general layout, process layout, material selection, etc. according to the corrosion medium and environmental conditions of the plant to ensure the safety of the plant structure.
The facade of the steel structure plant is mainly determined by the process layout. Under the condition of meeting the process requirements, the facade shall be simple and magnificent, and the nodes shall be simple and unified as far as possible. The color profiled steel plate makes the light steel plant buildings light and colorful, which is obviously better than the heavy and single traditional reinforced concrete structure. Jumping colors and cold colors are often used in the design of light steel plants, focusing on the main entrances and exits, outer gutters, edge flashing and other places, which not only reflects the magnificent momentum of modern plants, but also enriches the facade effect.