ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
The method of correcting deviation adopts the combination of steel plate reinforcement and weld transition, i.e. +1.1 m above steel column is installed to control the main position of the axis of the net at one time. After installation, the dislocation formed between the steel column and the end of the column under + 1.1 m is welded first, and then the qualified steel plate or weld is used to form a better force transmission. Pass. Therefore, steel plate is used to reinforce those whose cross-section value is more than 8 mm, and the cross-section value is less than 8 mm. The weld transition method is used to form a smooth transition. Concrete implementation of the following steel plate reinforcement method: for different degrees of deviation, different steel plate thickness. For vegetable use, 20mm (Q345C) steel plate is used for 1,15mm and 8mm. For those with 25mm or less than or equal to 15mm, 30mm (Q345C) steel plate is used. For those with more than 25mm (Q345GJ-C) steel plate, 40mm (Q345GJ-C) steel plate is used. The reinforcement node is shown in Figure 4. Sandblasting treatment of reinforcing steel plate reaches Sa2.5 grade, the steel plate needs to be flat, and the grooves on both sides of the steel plate are machined.
When welding, the steel column and the reinforcing plate should be preheated to 100 ~200 C, and the carbon dioxide gas shielded welding should be applied. The left and right sides of the welding seams should be welded by double symmetrical welding. Each welding seam will timely arrange the residues such as welding slag and spatter, and the temperature of the welding seam between the ramps should not be kept at the preheating temperature. Because there are many welds in the reinforced steel plate after welding, it is easy to accumulate stress. Therefore, in the process of welding, the transition method of welding seam by knocking the hammer on the side of the steel column and the middle of the reinforcing steel plate is used. When the deviation of the upper and lower steel columns is less than 8 mm and the deviation of each side of the upper and lower steel columns is less than 8 mm, the welding seam is used to transfer the staggered platform zeta smoothly and make the remaining height uniform. Because the height of weld is small and the requirement of weld surface forming is high during welding transition, carbon dioxide gas shielded arc welding is adopted with wire diameter of 1.2 mm and low energy. The construction schematic of weld transition method is shown in Fig. 5. 3. Comparisons and choices of rectification schemes: See Table 1, two schemes from technical requirements, quality assurance, progress requirements and economic benefits of comprehensive comparison, deterministic rectification "scheme for implementation 4, the conclusion of the vertically accelerated drawing"Lighting Number State (Primitive Illumination 001)"permissible scope, must be at the same time of construction. Measures should be taken to rectify the deviation, but the choice of the rectification scheme is very important, which mainly depends on the understanding and judgment of the designers and engineers on the structural stress and the current situation of the project.
It is very difficult to rectify the deviation in engineering, steel column deviation and so on. After discussing and confirming the reinforcement method and several rounds of expert meetings by Martin Design Firm, the author compares the one-time rectification scheme with the `progressive rectification Scheme'based on the principle of scientificity and prudence. Finally, the experts agree to adopt the one-time rectification scheme, which can effectively transfer the structural stress. Compensation avoids the phenomenon of more deviation in the process of gradual deviation rectification, solves the technical problem of deviation rectification of high-rise structural steel columns more safely, guarantees the construction quality and progress, and achieves good results. We write this paper in the hope of discussing and sharing this experience with colleagues on the vertical deviation correction method in the installation process of high-rise steel structures, and soliciting the help and correction of colleagues.