Principles for selecting the tower crane

As one of the necessary machinery for construction, the selection of Tower Crane is very different from other construction machinery because of its unique characteristics and special working mode. Then, how to select tower crane? There are some main principles:

1) Determination of main parameters

Tower crane basic parameters refer to the height of tower crane, the jib length and maximum load on jib end, etc. The jib length can be preliminarily determined according to dimensions (L*W*H) of building, and ensure the jib can cover the whole project with a little margin. The height of tower crane should be 10 ~ 15m higher than the maximum height of the building. The maximum load of jib end is determined by the weight of the object to be lifted given by the construction personnel. After the above three parameters are determined, the type of tower crane can be preliminarily determined.

2) Determination of installation method

Tower crane is the equipment used on the ground, its weight (1Ot ~ 200T) is far greater than the general construction machinery, so the installation mode of tower crane is also one of the main issues to be considered when selecting tower crane. There are three basic installation methods of Tower Cranes widely used at present: ①installing the Fixing Angle in large concrete blocks, ②the large chassis with ballast, ③traveling type. Different installation methods have different requirements on the ground pressure of the foundation, different types of tower cranes have different pressures on the ground also.

3) Determination of free standing height

The commonly used tower crane can be raised as the building rises. When the height of the tower crane exceeds the "free height", if it rises again, it needs to adopt the "Anchorage Frame" measure, which is to "anchor" the tower crane together with the building under construction. The height of the first anchorage frame is different for different types of tower cranes, and the distance between each two "anchorage frame" is also different. The anchorage frame of tower crane has extra lateral tensile force on the building in construction, which requires the completed part of the project can reach a certain strength. If the construction speed is fast, the anchorage frame part has not reached the predetermined strength, which will affect the construction schedule. In this condition, the tower crane with higher free height should be considered.

4) The effect of surrounding environment the effect of surrounding e

The surrounding environment includes transportation roads, underground pipelines, the height of the surrounding buildings and high voltage lines. The structure parts of the tower crane are long and heavy, generally 10m long, so large transport vehicles and large tonnage truck cranes are required for installation, and when the project is completed, the same equipment will be used to dismantle it. Therefore, the surrounding environment also has a certain restriction on the selection of tower crane.

5) Other considerations

The above aspects are the selection principles for the independent construction of a single tower crane. When the height of the building is very high (more than 150m), the internal climbing tower crane can be considered; When the building covers a large area and the shape is irregular, multiple tower cranes with different sizes and heights should be selected for joint configuration. The principle of configuration should not only cover completely, but also cannot interfere with each other. Each tower crane should be placed in the most appropriate position according to the different workload and working cycle. In addition, attention should also be paid to the large power consumption of tower cranes, generally dozens of kilovolts, so the installation site as close as possible to the site of the transformer, and at the same time should avoid too close to the high voltage line.