Application advantages of structural steel pipe

　　1) compared with the section steel with ordinary open section, the section of steel pipe (square and rectangular) has the characteristics of flat surface, no dead angle and small surface area, which is not only conducive to saving anticorrosive and fireproof coating, but also convenient for dust removal;

　　2) the resistance coefficient of steel pipe section is small, so it has obvious advantages when it is used in fluid (such as wind and water flow) environment;

　　3) the cross section has the characteristics of biaxial symmetry, superposition of centroid and shear center, etc.; the moment of inertia of cross section is the same for each axis, so it has prominent advantages as a flexural and compression structure; the cross section is closed, with large torsional rigidity, good local stability, simple and smooth appearance, saving structural steel;

　　4) the pipeline can transmit liquid. At present, according to the characteristics, the oil pipeline bridge and rainwater drainage pipe have been developed;

　　5) prestressed steel wire rope can also be placed in the pipe to apply internal prestress;

　　6) the internal space of steel pipe structure can be used. For example, filling concrete can not only improve the bearing capacity of components, but also extend the fire resistance of components;

　　7) it also has the advantages of light weight, high strength, good anti-seismic and anti disaster performance, energy conservation and environmental protection, energy recycling, etc;