First step materials 

Strict control of steel structure engineering materials is the first step. Before fabrication and processing of steel members, check whether the variety, model, specification and quality of steel meet the design requirements and the current national product standards, and take samples at random for retest, which can only be used after passing the retest.The high-strength bolt connection pair shall be retested for prestress to meet the design requirements.The anti sliding coefficient test shall be conducted on the connection surface of high-strength bolts, and the minimum value shall meet the design requirements.In addition, the matching welding rod, welding wire and flux with factory certificate must be selected according to the steel grade.

Step 2 installation 

The installation method of steel structure engineering is very important. After the foundation bolts are leveled, the connection should be to install a span of column beam first according to the regulations, and the column beam should be installed with good support to make it a system.After the installation of one span, install the next span.In this way, the installation is safe without any force and hidden danger.The positioning of the steel column shall be accurate, the elevation of the column top shall be consistent, and on the same straight line; the verticality of the steel column shall be strictly monitored, and a theodolite shall be set in 90 ° direction within the range of ⊿ not affected by machinery & steel structure engineering.The quality of bolt connection and manual welding directly affects the safety of steel structure.The correct choice of connection method and reasonable design of connection form is an important part of steel structure installation.

Step 3 Technology 

The best materials and methods require sufficient construction technical experience of the construction personnel. The steel structure works mainly adopt welding, riveting and bolt connection. The technical qualification certificates and operation safety certificates of welders, crane workers and other special types of work shall be inspected, and the qualification and validity period of the certificate issuing unit shall be checked.At the same time, the project department is required to establish a quality assurance system, implement the three inspection system, and the technical personnel are required to work with certificates