ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
A theodolite is set up at the intersection of two vertical control lines. Another theodolite is set up on the installation axis of the vertical steel column. The control line is monitored at the same time when the central axis of the alignment steel column is moved out. The measured axis of the column is measured back to the steel column with a steel ruler. Compared with the axis of the steel column itself, the axis of the column body adjusted to two directions coincides with the control line. At the same time, the reference line at the bottom of the steel column is projected to the top of the column by theodolite, and compared with the central axis at the top of the column. When the steel column is adjusted to coincide with the two lines, the verticality of the steel column is adjusted in place. The above measures basically eliminate the influence of external factors on measurement accuracy and effectively ensure the installation accuracy and construction quality of steel pipe columns. 2.2 Because of the particularity of the section of the pipe column, the key to the quality control of the project construction is to control the ellipticity of the pipe column, the system of making and installing the datum line.
Therefore, by optimizing the production and installation process, formulating detailed technical guidance and refining the installation and correction technology of the cylinder, we can effectively ensure the construction quality of the pipeline. 2.2.1 The inspection of steel pipe column is to measure the pipe column entering the site, and to measure the connection between the upper and lower cylinders, to check whether the ellipticity of the pipe column and the installation datum line meet the standard, whether the dimension deviation of the connection between the upper and lower cylinders meets the standard requirements, and to mark the parts that do not meet the requirements. 2.2.2 Correction Technology for Steel Pipe Columns (1) Correction Technology for Steel Pipe Columns refers to the first correction before installation of beams, that is to say, all indexes of the columns are required to meet the requirements of inspection and acceptance. In the super high-rise structure, if the so-called integral correction is carried out after the shape, it is difficult to achieve the correction effect due to the mutual restraint of the supervisory components, so this method is not recommended. After the preliminary calibration is completed, the beam should be installed symmetrically from the middle span to both ends; for the same span, the lower beam should be installed first, and then the upper and middle beam samples can be installed to facilitate lifting and reduce the impact on the column verticality.
Correction of steel columns is also carried out according to the idea of radiation and extension from the middle to both ends. (2) Correction of steel pipe column is the key technology of steel structure construction. After the steel column and the main beam connected with it are hoisted in place, the measurement and correction of the steel column are carried out. The contents and order of the rake correction are: the correction of the positioning axis of the steel column, the adjustment of the elevation of the steel column, the adjustment of the torsion of the column body and the correction of the vertical degree of the steel column. In view of this project, we divide it into two working sections, northwest and southeast, according to the actual situation and the requirement of flow-shop operation. Each working section uses the method of progressively advancing 9 steel columns from the middle to both sides and from two directions to the corner columns to correct them, waiting for the correction of the middle portal column, the final twisting of the high-strength mule bolt, the column and the corner column. After the beam is welded, a fixed rigid small frame is formed, and then the steel columns on both sides of the frame are corrected to both ends at the same time. Because of the particularity of the position of the corner column, in order to eliminate the influence of welding deformation of other steel columns and beams, the remaining seven steel columns on the two intersecting axes should be re-tested and welded after welding, so as to ensure the installation accuracy of the corner column.
The calibration process is implemented in three schools, namely, one school column mouth, two school beam mouth, three school column top displacement and verticality. "This not only ensures the independence of the verticality of a single steel column, but also effectively controls the overall plane positioning and verticality of the structure. 2.2.3 Correction of the positioning axis of the steel column may occur at the end of the column during processing, transportation and installation. In order to prevent the misalignment of the butt ports between the upper and lower sections of the steel column, it is necessary to make the butt face of the steel column smooth or transition smoothly on the premise of ensuring the overlap of the cross central line between the upper and lower sections of the steel column and the installation axis. Big wrong side. In the process of installation, if there are too large misalignment and misalignment, the cushion plate is clamped on the different sides of the connecting ear plate between the column and the column [thickness is 0.5-1.omm], and the cross-line deviation of the steel column is adjusted within 3 mm. If the deviation exceeds the allowable value of the code, it needs to be adjusted several times. [It is necessary to ensure that the axis deviation of the single section of the steel column meets the requirements of the code.) After adjusting the staggered edge of the steel column to within 3 mm allowed by the code and hoisting the adjusting steel column with 2.2.4 elevation, the upper and lower ear plates are determined by installing mule bolts through the connecting plates, but the connecting plates are not tightened. By lifting the hooks and prying bars, the number of the two doors to the columns is determined, and the number of the finished points is calculated, and each steel column will be set at the same perimeter. The measured elevation results and the pre-inspection length of the lower section column are comprehensively treated before or during the installation. For the deviation of elevation from the design value is + 10 mm or more, the processing plant extends the upper section of the steel column body to ensure that the installation elevation of the steel beam and the elevation of the steel column meet the design requirements; and for the elevation deviation from the design value, the processing plant extends the upper section of the steel column body. The width of butt weld of chirped steel column is adjusted to ensure that the elevation of each steel column meets the requirements of design and specification.