Seismic Performance
1. Lightweight and High - strength, Reducing Seismic Action
Steel Structure buildings are mainly composed of steel. Steel has high strength. To meet the same bearing capacity requirements, the self - weight of a steel structure building is approximately half or even more lighter than that of a traditional concrete structure. According to the seismic action calculation formula, the seismic force is proportional to the building mass. The lighter self - weight significantly reduces the seismic action on steel structure buildings during an earthquake, reducing the risk of structural damage. For example, in areas with the same seismic intensity, the seismic force on a steel structure residence is significantly less than that on a concrete residence, providing an inherent advantage for the structure's earthquake resistance.
2. Good Ductility and Energy - dissipation Capacity
Steel has good ductility, which means it can undergo large deformations before failure under stress. In a steel structure building subjected to an earthquake, the components can absorb and dissipate seismic energy through their own deformation, avoiding sudden brittle failure of the structure. For instance, in a steel structure industrial plant in an earthquake - stricken area, when an earthquake occurs, the steel beams and columns will bend and deform to a certain extent, but still maintain the overall stability of the structure, buying time for personnel evacuation and rescue.
3. Flexible Structural Systems
Steel structures can be designed into various flexible structural systems, such as frame structures, frame - braced structures, and tube structures. These structural systems can be optimized according to building functions and seismic requirements. In a frame - braced structure, the braces can effectively increase the lateral stiffness of the structure. During an earthquake, they bear most of the horizontal forces, while the frame ensures the spatial integrity and vertical bearing capacity of the structure. The two work together to significantly improve the seismic performance of the structure.
4. Reliable Connection Nodes
Connection nodes in steel structures mostly adopt methods such as welding and bolt connection. A reasonably designed connection node can ensure the effective transfer of forces between components and has a certain degree of ductility. Welded nodes can integrate components into a whole, and bolt - connected nodes allow a certain rotation of the nodes under seismic action to dissipate seismic energy. In high - rise steel structure buildings, the beam - column connection nodes are specially designed to not only bear vertical loads but also work reliably under seismic horizontal forces, ensuring the stability of the structure.
Wind - resistance Performance
1. High Strength, Strong Wind - load Resistance
Steel has high strength, and steel structure components can withstand large tensile forces, compressive forces, and bending moments. Under the action of strong winds, they can effectively resist the horizontal forces and overturning moments generated by wind loads, preventing the structure from being damaged or collapsing. A steel structure lighthouse in a coastal area, which is constantly attacked by strong winds throughout the year, stands firmly relying on its high - strength steel structure frame, ensuring the normal navigation function.
2. Good Structural Integrity
Steel structures form a tight whole through welding, bolt connection, etc., and the cooperative working ability of each component is strong. When wind loads act, the structure can evenly transfer the wind force to the foundation, avoiding the damage of local components due to concentrated stress. In a large - scale steel structure gymnasium, the roof and the main structure are closely connected. In strong wind weather, the wind load can be effectively dispersed to ensure the safety of the building.
3. Reasonable Building Shape and Shape Coefficient
During the design stage of a steel structure building, the building shape can be optimized based on means such as wind - tunnel tests to reduce the shape coefficient. A streamlined building shape can reduce wind resistance, allowing the wind to flow more smoothly over the building surface and reducing the force of the wind on the building. Super - high - rise buildings with a circular or elliptical plane shape have a smaller shape coefficient and better wind - resistance performance compared to square - shaped buildings.
4. Good Lateral Stiffness
For high - rise buildings and tall steel structures, the lateral stiffness of the structure can be significantly increased by setting a reasonable bracing system, shear walls, or tube structures. Under the action of strong winds, a small lateral displacement can ensure the stability and functionality of the structure, preventing structural damage or affecting the normal operation of internal equipment due to excessive deformation. A steel structure super - high - rise office building in the city relies on the cooperative work of the core tube and the outer steel frame to have sufficient lateral stiffness to resist the invasion of strong winds.