The plan for lifting steel structures is to use two lifts or segmented assembly methods based on the characteristics of the site project, the duration of the project, and the construction situation. Sometimes, large-scale mechanical lifting is used for on-site lifting. In addition, attention should be paid to the sequence of lifting, which is very important.
The installation of high-rise steel structures generally starts from the ground and then undergoes underground work in terms of lifting construction sequence. The construction should be carried out in the order of the main structure first, followed by the secondary components. This order should not be disrupted, otherwise it may affect the smooth progress of the construction.
The most closely related to the quality of engineering management is the safety situation of steel component lifting construction and the installation management of embedded parts. Therefore, in the installation process of embedded parts, accuracy control is generally carried out based on the construction specifications of steel components, or correction work is carried out according to the regulations on the drawings.
The steel column is transported to the site, and the crane rotates while lifting the hook, causing the column to rotate around the column foot and lift the steel column. (Note: When lifting, a wooden pad should be placed under the column base to prevent friction with the ground, while ensuring that the lifting point and column base are on the same arc as the rotation of the crane boom.).
The steel column is lifted by a single machine or two machines. The crane only lifts the hook to make the steel column base slide and lift the steel column. A taxiway is laid between the steel column and the ground.
Double or three machine lifting, in order to reduce the frictional resistance between the steel column foot and the ground, one of them is the auxiliary machine, and the lifting point is selected below the steel column. When lifting the column, it is coordinated with the main machine to lift the hook. As the main machine is lifted, the auxiliary machine needs to walk or rotate. During the delivery process, the auxiliary machine bears a part of the load and delivers the steel column foot to the steel column foundation. The auxiliary machine unhooks and unloads the load. At this moment, the main machine is fully loaded, and the steel column is placed in place.
How to hoist the installation of high-rise steel structures? Generally, steel columns have good elasticity, and the lifting point adopts a one point lifting method. The lifting lug is placed at the top of the column, and the column body is vertical, making it easy to align and correct. Due to the limitation of the length of the lifting arm through the center of gravity position of the column, the lifting point can also be set at 1/3 of the column, and the lifting point can be tilted. Due to the inclination of the steel column, alignment correction is relatively difficult.
The position and number of lifting points are determined based on the shape, cross-section, length, weight, and lifting performance of the steel column.