• International Journal of High-Rise Buildings
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• v.11 no.2
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• pp.103-114
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• 2022

Tower crane is of great importance in the construction of high rise buildings. A self-lifting & slewing multi-cranes platform (referred to as crane slewing platform) was developed to optimize the configuration of tower cranes, as well as solve the problems of cooperative operation conflict between multiple cranes and other construction equipment and their respective climbing and occupying of construction period. The design and test of the slewing platform was introduced. By applying the slewing platform in the construction of Chengdu Greenland Center super high rise building project, some key technologies such as the configuration of cranes, the installation, construction and lifting of the slewing platform are implemented and validated. Up to now, the slewing platform has been safely lifted up 98 times in Chengdu Greenland Center project construction, and achieved good social and economic benefits.

• Journal of the Korean Society of Safety
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• v.36 no.1
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• pp.9-17
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• 2021

This study analyses the load imbalance of the tower crane used in telescoping work for structural safety, owing to the difference in wind speed and balance weight position. This is because wind speed and position of the balance weight have a significant impact on the structural stresses of a tower crane during telescoping work. Therefore, structural analysis was performed on the 290HC model, which is often used at construction sites and has only one cylinder installed. Moreover, two models were classified to determine the load acting on the connecting part of the telescopic cage to slewing platform and the cylinder. Five types of balance weight positions were applied at regular intervals from jibs; moreover, four types of wind load criteria were differently applied. Hence, the telescopic cage columns were destroyed at all balance weight positions at a wind speed of 30 m/s and only at certain locations at a wind speed of 20 m/s. Furthermore, failures occurred for cylinders, torsional, and bending at wind speeds of 30 m/s and 20 m/s, load imbalances above the allowable thresholds considering the safety factor. In addition, the load imbalance in the telescoping work also varied depending on the position of the balance weights. The results of these studies have validated that the current standards of adjusting the appropriate position of the balance weights on the jib are completely valid, with the telescoping work to be executed only at wind speeds of less than equal to 10 m/s.