In recent years, steel structure building applications in various industries is becoming more and more common, both many high-rise buildings and large span Bridges, and have found application in various industries, can be built as the main framework components can also be as a single part of the support structure, can be used according to demand on different parts.
Steel structure engineering can be divided into a variety of types, such as overpass, canopy, attic, workshop, warehouse, office building, as long as it needs to use steel structure part of the structure, can be used as steel structure engineering.
During the construction of steel structure engineering, if you want to carry out high quality, you cannot do without the design of pre-assembly stage of steel structure processing plant, the control of construction stage, and the strict control of construction quality on site. The specific points of steel structure construction process please read below.
1. Review the drawing design of steel structure
(1) Deepen the design of the drawing process, and design the small parts according to the classification of the parts for the process with complex shape.
(2) Before the process, the staff should deepen the design of the workpiece according to the actual situation of the environment, and use the computer to loft the parts to ensure the correct size of the parts.
(3) Before cutting, the selected base material should be cleaned. After cutting, the surface of the cutting place is smooth and free from cracks, slag and splashes.
(4) Welding shall be conducted according to the welding parameters and welding sequence in the specification. The thick steel parts shall be preheated before welding, and technical preparation for correction shall be made.
2. Site preparation
(1) Ensure that the pre-assembled site is flat and solid, eliminate the possibility of uneven settlement, and adjust the side by point.
(2) Side datum point and elevation line should be set for pre-assembly, and temporary connecting plate can be set.
(3) The location of steel components should be reserved in advance on site, and pre-assembly and hoisting positioning should be carried out according to the lofting size. Parameters such as construction drawing control size and welding shrinkage allowance should be taken into consideration.
(4) The lofting size of the site shall be checked, and the lofting point and line position shall be marked for pre-assembly.
3. Pre-assemble the factory section
(1) Divide the pre-assembly units, correct the precision of the piecewise assembly frame and roof trussing, and work out the pre-assembly sequence of adjacent units for assembly.
(2) Test the tire frame after assembly is completed, correct the height and position of the beam section, and check the punctuation and height of the baseline tire frame.
(3) The position control points are set according to the structure of the piecewise unit to strictly control the piecewise linearity, the matching property of adjacent segments and the accuracy of the connection and plug ends.
(4) Conducting welding in sections to reduce errors caused by welding deformation of components.
4. Assembling and welding of steel structure
(1) Control the spacing between welded H-beam flange joints and webs is not less than 200mm.
(2) check whether the top contact surface meets more than 75% of the area close.
(3) The allowable deviation of the intersecting point of the axis of the truss structure members is not more than 3mm.
(4) when the total area of the assembly is 300 ~ 1000㎡, the tolerance is not more than 2mm;When the total area of assembly is 1000 ~ 5000㎡, the tolerance is not more than 3mm.
5. Bolt connection construction of steel structure
(1) Check the supply quality of high strength bolts to avoid shacking, and handle the connection surface of high strength bolts to ensure that the leveling and sealing meet the requirements and the bolt holes meet the design requirements.
(2) During the construction, ensure that the high strength bolt is screwed according to the specification, the initial screw and the final screw can not be completed at one time, and must use _ tools to eliminate subjective estimation phenomenon.
(3) Strengthen the execution of quality measures such as side station supervision, parallel inspection and random sampling inspection to ensure the quality of high-strength bolt connection reaches the standard.
6. Control points of steel structure assembly
(1) Assembly shall be carried out in process assembly sequence. The concealed weld shall be electrically welded first, and then covered after passing inspection.
(2) it is strictly prohibited to assemble in order to avoid forced assembly.
(3) test the tool and a finished product first when assembling large parts, and then carry out assembly work in large quantities after passing the test.
7. Anti-corrosion coating construction of steel structure
(1) Anti-corrosion coating is mainly divided into anti-atmospheric corrosion and anti-soil corrosion. During construction, the thickness of each layer of coating and the coating process must be controlled to meet the standards, and the anti-corrosion method should be reasonably selected in combination with climate and environmental factors.
(2) according to the building grade to measure the structural beam, column, plate and other different components of the fireproof time, and according to different requirements of the coating of different thickness or type of fireproof paint, quality inspection must be compared with the design requirements for inspection and verification.
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