Sichuan steel structure - hoisting related knowledge and precautions

During the construction of Sichuan steel structure project, because the main steel part and the roof panel part are relatively large in volume and heavy in weight, they need to be hoisted by crane. There are many scientific and reasonable methods and experiences in the lifting process that are worth our reference and learning. At the same time, in the process of lifting materials, safety is also the focus of the whole process. Before the lifting of steel structure engineering materials in Chengdu, it is necessary to make full preparations and carefully check all aspects of the site, especially to check the fixed position of the fixed column. In the lifting process, pay attention to the various signal cooperation of the ground and operation, and pay attention to the lashing and lifting position of the material. Let's learn more about the knowledge and precautions about all aspects of lifting in Sichuan steel structure engineering.

1. Preparation before column hoisting: after the on-site inspection is qualified, the stacking and driving route are determined, that is, check the axis position, flatness and elevation of the embedded plate and embedded bolt, and after the inspection and measurement are qualified, screw the foundation bolt (under the column) to the embedded bolt, and use a level or theodolite to level the foundation bolt to the same level, and fix it appropriately. The column is transported to the determined position according to the number and placed according to the regulations, the placement position is that the center of the column foot should form a concentric arc in the center of the fundamental surface, the column should be appropriately 20~30cm high, and prepare the square wood of the appropriate specifications. Before the column is hoisted, the various reference points, center lines, lifting (strapping) points and the surface of the column should be checked again for damage and dirt, and only after confirming that it is correct can it be bundled and hoisted.

2. Column lifting method: Sichuan steel structure engineering lifting mainly adopts the rotation method, that is, the crane rotates the lifting arm while lifting, so that the column is in place after being in an upright state. The process mainly includes lashing, lifting, alignment, temporary fixation, correction and final fixation. First of all, use the theodolite along the central axis to 90 degrees, adjust the position and debug, in order to correct the position and verticality of the column, with a sling and active clamp ring at the lifting point with a graphical method for binding, by the crane side slowly lifting the lifting edge to rotate the lifting arm, wait for the column to be straightened and make the column bottom plate embedded plate 10~30cm when stop, by the manual and theodolite aligned with the column bottom plate and embedded plate cross center line position and slowly lowered, while using the theodolite to control the column verticality and center offset, after the column position is completely accurate, Adjust the base bolt under the column bottom plate, and tighten the bolt under the column bottom plate to fix the column position. The hoisting group must be clear and clear before lifting, the measurement, hoisting, fastening and other equipment are complete, and the quality and safety engineers of crane, command, measurement, alignment, lashing and on-site construction do their duty, and minimize the approach of idle personnel.

3. Preparation before lifting steel structure beams in Chengdu: After the column is hoisted in place and tested and qualified, the main beam hoisting preparation should be carried out immediately, and each main beam lifting point, alignment reference and center line should be checked, and a small station frame should be built at the upper end of the column to facilitate the safety of the aerial splicing station.

4. Lifting method: steel structure engineering adopts iron flat bearer, two-point lifting method, hoisting with iron flat stretcher two-ended sling beam lifting point binding, and then iron flat stretcher on the sling and crane hook sleeve, when lifting, first try the beam center of gravity offset (beam to maintain balance), after confirming that it is correct, normal lifting, hoisting to the assembly position, by the column workers to find the center position, respectively with high-strength bolts to connect the screw holes of the column of the secondary connecting beam, and then respectively put on the nut for initial screwing, after confirming the accuracy of the installation, use the force plate hand final screwing fixation.

The above are the methods and precautions before hoisting and the process of hoisting based on the preparation work before hoisting and the process of hoisting summarized according to many years of on-site hoisting experience. These scientific and effective methods have played a huge role in our actual steel structure engineering.