Analyze and summarize how to improve the accuracy of steel structure body installation

 In the construction industry, as the utilization of steel structure main body becomes more and more popular, the fabrication, transportation and installation process technology of steel structure main body has been paid more and more attention to, and at the same time has been developed faster and improved continuously. Further improving the precision of fabrication and installation of steel structure main body and reducing the cost is a topic in front of the steel structure main body industry. Provisions and industry standards have already made a lot of regulations in this regard, putting forward requirements for every step from parts discharging to completion.

Accuracy of the fabricated dimension of steel structure main body is the basic and prerequisite to ensure the accuracy of the overall structural dimension and smooth installation of steel structure main body. Therefore, it is necessary to accurately grasp such things as the straightness and twist of steel columns, the distance from the connection holes of columns and girders to the bottom plate of the columns, the machining precision of the connection holes themselves, the straightness of roof girders and the machining precision of the column and girder connection plates, the positional dimension of the bollards or support connection plates on the girders and columns relative to the girders and columns themselves, and the positional dimension of purlin brackets. Position size, position size of purlin joining plate, etc.

At present, the columns in the main body of steel structure are processed by outsourced H-steel or assembled by plates; if they are processed by ready-made H-steel, the production accuracy of columns is easy to control; if they are assembled by plates, attention should be paid to shaping the steel columns after assembling and welding, so as to ensure the straightness of the steel columns and to prevent distortion. Most of the roof beams are herringbone structures, often assembled from 2 or 4 bays. Roof beams are generally assembled by the fabricator with plates, and the webs of the beams are often irregularly quadrilateral. Manufacturers with strong technical ability can accurately master the release of the webs, while those with weak technical ability can deviate from the size of the webs from time to time. As the external dimension of roof beam is related to the tightness of the connection between beam and column, the dimension of web plate directly affects the external dimension of beam, thus it is especially important. In the general design of the main body of the steel structure, the roof beam often also has a certain arching requirements, the purpose is to offset the overall installation, the beam due to its own and the role of the roof load and the deflection generated by the installation of the dimensions. The height of the arch is determined by the design. In order to ensure the degree of arching, the external dimensions of the roof beams have to be adjusted to a certain extent. In this respect, the production of beams is much more difficult than that of columns.

The external dimensions of the beam and the beam end connection plate are key inspection items, the purpose of which is to ensure the overall effect after installation and the tightness between the beam and the column. We once found such a situation, after the installation of beams and columns between the wedge-shaped gap, when the large hexagonal head bolts have lost the original design of the most important role, only to assume the role of support, no friction between the beams and columns. Later in each column immediately below the beam connecting plate, increased the shear key to improve the support capacity of the roofing system, practice has proved that the effect is very good.

In actual construction, due to a variety of factors that make the beam and column often can not be tightly combined, some seem to seem to be combined, but in fact do not meet the requirements, resulting in the relative weakening of the friction between the joints. In view of this, in the design of the main body of the steel structure, in the column panel immediately below the lower edge of the beam connection plate to increase the shear key to ensure that the columns on the roof of the support capacity. Although the shear key is small, but the role is great.

In order to avoid and reduce the deformation of columns, beams, ties and other connectors during transportation, the transportation company should be required to tie up the components, must increase the support points in the full length, as far as possible between the components with wood pads, peripheral ties to be firm to minimize the deformation of the components due to vibration or heavy pressure during transportation; in loading and unloading should be used with two-point suspension, such as components of the super-length, can be used and appropriate stretcher Increase the lifting point; components in the installation site stacking, should minimize the number of stacking layers, generally no more than 3 layers, and at the same time to appropriately increase the support point, to prevent deformation of the components under pressure. Never relax the control of transportation, lifting and unloading, stacking, etc. Otherwise, even if the steel structure main body components are made more accurately, there will be problems in transportation and other aspects, which will lead to big troubles in steel structure main body installation.