6 Main Points of Steel Structure Building Technology:
Assembly and welding
Assemble in sequence. When there are hidden welds, welding shall be performed first. In order to reduce deformation, small pieces shall be welded first, and then large pieces shall be assembled after correction. Plate and profile should be spliced before assembly, pay attention to the control of welding residual stress.
The hidden parts of the components should be painted in advance. The rust, oil and other impurities on the surface of the groove and on both sides of the welding parts should be removed before welding. During the assembly of the truss structural rods, the intersection point of the axis and the allowable deviation should be mainly controlled.
During assembly, the endplate shall be pressed against the polished or sandblasted parts, and it shall be checked whether at least 75% of the pressing contact surface is close to them.
The electrode must be combined with the technical requirements of the product before the use of drying, the acid electrode is generally 150°C drying, time 1~2h, the alkaline electrode is generally 350~400°C drying, time 1~2h. It should not be more than 2h from taking out the electrode to welding after drying, and the drying times of a single electrode should not be more than 2 times.
Welding shall be performed on the assembled components. Before welding, the welding process parameters and welding sequence shall be checked.
Technical parameters of high-strength bolts shall be re-checked before use, and torque correction shall be carried out before and after work, and the control error shall not exceed 3%.
When there is more than 1/20 slope on the upper and lower contact surfaces of high-strength bolts, a gasket should be used to pad flat. Holes for high screw degree bolts must be drilled with no flash or burr at the edge of the hole, and the inclination of the centerline should not be greater than 2mm.
the installation of high-strength bolts is carried out after the central position of the structural member is adjusted, so that the direction is consistent, to facilitate the later returning and inspection.
When fastening the high strength bolt, it should be fastened from the part with high stiffness to the unconstrained end, and fastened from the middle to the periphery.
The single-layer construction according to the maximum weight of a single component, the number, size, structural characteristics, installation height and other order to determine.
Arrange hoisting machinery according to the requirements of the project quantity and project schedule, which not only ensures that the hoisting requirements are met, but also meets the economic rationality.
Before lifting, the foundation axis and elevation shall be checked with the measurement control network, and dust and other sundry things on the surface shall be cleaned before installation; If the anticorrosive coating on the surface of the structure is damaged during the lifting process, it shall be timely repainted and checked for acceptance again.
When lifting the steel column, hemp rope should be hung at the bottom to avoid free sliding of the steel column after lifting. Manual alignment should be supplemented when approaching the installation position, and bolts and nuts should be tightened in time after being in place to make the steel column temporary reinforcement.
Before assembly, stitching and construction, the allowable deviation of the dimensions shall be checked, and the unqualified ones shall be prohibited from lifting and installation.
After the completion of the installation of the main steel structure, the perpendicularity and levelness of the steel frame shall be measured with the theodolite to ensure that the error meets the design requirements.
When the main structure of a single-layer steel structure is hoisted, its overall perpendicularity and overall plane curvature should be checked after it is in place, and the deflection of the steel column should be checked.
When the partial project is accepted, the following contents shall be checked: engineering drawings and relevant design documents; Raw material quality certification documents; On-site quality inspection records; Inspection records of strong bar inspection items; Acceptance record of concealed works; Disposal record of nonconformance and acceptance record.
Finished product protection
After the acceptance of assembled finished products of steel structure, the finished products are generally stacked, and the bottom filling is stable to ensure a solid foundation and prevent deformation of steel structure; At the same time, but also appropriate space pad to prevent water.
During the transportation of steel members, the transportation section shall be divided according to the length and weight of the steel members, to ensure that the fulcrum and extension length of both ends of the steel members on the vehicles will not lead to structural deformation, and at the same time protect the anti-corrosion coating from scratching.