The selection of tower cranes should mainly consider the number, location and model of tower cranes from the following aspects: The determination of the number and location of tower cranes is mainly from the perspective of covering the entire working surface, which can be determined from the construction plan drawing. The second is to preliminarily determine the type of tower crane from the workload of the tower crane and the maximum lifting capacity. When the number of tower cranes exceeds one, the cooperation between the main tower and the auxiliary tower must also be considered. Although from the management point of view, tower cranes of the same model are easier to manage, but tower cranes of different models are more conducive to use.
In order to ensure safety, the two adjacent tower cranes should have a height difference of 5 ~ 6m. This problem is particularly important when the tower crane needs to be attached to the wall. After initially determining the number and location of tower cranes from the construction plan, you can proceed to the next step; further determine the location and model of tower cranes from the entry and exit conditions of tower cranes: the main considerations are the entry and exit roads, underground and air obstacles The situation of the object is relatively complicated and needs specific analysis. The maximum height of the tower crane should be determined in this way based on the elevation of the parapet of the building (the foundation of the tower crane is on the same level as ± 0 of the building Time), if the building is a cast-in-place concrete structure using a large overall formwork, the height of the hook bottom of the tower crane should be greater than the building height by 12-15m, if the combined formwork or building is a frame structure, this height difference It can be 8 ~ 10m.
This is also one of the conditions that determine the type of tower crane; the tower crane's attached wall: different tower cranes have different attached wall heights and attached wall intervals, the basis of consideration is the project progress and the ambient temperature. To put it simply, before the concrete strength of the wall joint reaches 70%, the tower crane has enough hook bottom height, which also determines the choice of tower crane model. The distance between the attached walls refers to the great distance between two attached walls of the same tower crane. This problem will affect the continuity of construction, especially in the cast-in-place concrete buildings using large formwork. In the summer, the concrete strength reaches the standard fast, and the requirement for the parameter "distance between two attached walls" of the tower crane may be smaller, and vice versa.
