How does a cantilever crane work?
Cantilever crane working strength is light, the crane is composed of the column, the slewing arm slewing drive device and the electric hoist, the lower end of the column is fixed on the concrete foundation through the anchor bolt, by the cycloid reducer to drive the cantilever rotary, electric hoist on the cantilever I-beam for straight line running around, and lifting heavy objects. The crane arm is hollow steel structure, light weight, large span, large lifting weight, economic and durable. Built-in walking mechanism, using special engineering plastic wheel with rolling bearing, small friction, walking fast; Small structure size, especially conducive to improving the hook stroke.
In the cantilever crane, the cantilever assembly method uses the cantilever crane to lift the prefabricated beam segments to the installation position, and then uses the epoxy resin glue and the application of prestress to connect the prefabricated beam segments into a whole. The segment number of cantilever assembly mainly depends on the lifting capacity of the cantilever crane, and the segment length is 2 ~ 5 m. Section is too long since the major, need to hang the lifting capacity of the crane, section is too short, the assembly joint, the period is also extended. Due to the large cross-sectional area and short segment length, the cantilever root gradually increases to the end.
The assembly includes hoisting and positioning, epoxy adhesive and prestressing process. Generally, it takes about 1 ~ 1.5 days to assemble a segment.
In addition, in the cantilever crane, using cantilever construction, prefabrication of beam section can be carried out simultaneously with the construction of bridge substructure, reducing the shrinkage and creep of concrete beam section, which is beneficial to the alignment of the main beam in the later stage of bridge formation. In addition, the cantilever assembly method is used for construction, the beam section is prefabricated in the site, and the quality is easy to ensure. However, the assembly is bonded by epoxy adhesive, and the prestressed bundle is connected through the bundle in the reserved channel. Compared with the cantilever casting method, the structural integrity is poor, and the construction deformation control is more difficult, and the closing accuracy is often low.
