Steel is characterized by high strength, light weight, good overall stiffness and strong deformation capacity, so it is particularly suitable for the construction of large-span, super-high and super heavy buildings; the material has good homogeneity and isotropy, and is an ideal elastic body, which is in line with the basic assumptions of general engineering mechanics; the material has good plasticity and toughness, can have large deformation and can bear dynamic load well; the construction period is short; the construction period is short;It has a high degree of industrialization and can carry out specialized production with high degree of mechanization.So we need to pay attention to when installing steel structure?

What are the precautions for installation of steel structure engineering?

　　1.Friction coefficient: F is the force that causes the initial slip of the specimen measured by the anti slip test, NF is the number of friction surfaces, and is the sum of the measured values of the pre tension of the high strength bolt corresponding to F. 

　　2.Torque coefficient: where D is the nominal diameter of high strength bolt (mm), M is the applied torque value (n · m), and P is the bolt pre tightening force.The average value of torque coefficient K must be 0.110 ~ 0.150 for 10.9 grade high strength large hexagon bolt connection.The standard deviation should be less than or equal to 0.010.

　　3.Initial tightening torque: in order to reduce the influence of steel plate deformation in the process of bolt tightening, secondary tightening can be used to reduce the interaction between successively tightening bolts.The first tightening of high strength bolt is the initial tightening, so that its axial force should reach 60% – 80% of the standard axial force.

　　4.Final tightening torque: the final tightening torque of high strength bolt is the final tightening torque.Considering the loss of prestress, the final tightening torque is generally 5% – 10% larger than that calculated theoretically according to the design pretension.