Research On The Mechanical Properties Of Attachment Support System Affected By Large Boom Internal Climbing Tower Crane

In the construction of super high-rise buildings,the large boom internal climbing tower crane is playing a more and more important role,in which case,the safety and stability of them deserve attention.The tower's supporting system,consisting of two parts,one of which is the supporting structure and the other is the attachment wall has a great effect on the normal work of the large boom internal climbing tower crane.In addition,as the deadweights of the main tower crane and the rated lifting torques in ultra-high-rise buildings are comparably large,it's a must to have a supporting system whose mechanical properties are in a high level.Therefore,it's necessary to design experiments for actual detection and statistical analysis,in condition that the relative data cannot be entirely confirmed from theoretical arithmetic.Based on an actual project,this paper is a research on the mechanical properties of the tower crane's supporting system under the effect of the tower crane,which can be divided into two parts,the theoretical testing for supporting system under complex mechanical situation and the analytical research of the mechanical properties of attachment walls.The conclusions we got are in the following aspects:1)The effects of the tower crane on tower crane's supporting system include two parts which are the vertical load and the horizontal load,and the vertical load matters more than the horizontal load.The internal force of the supporting system from these two types of load can be superposed.The upper-level supporting is mainly influenced by the vertical load while the lower-level supporting is effected by both the vertical load and the horizontal load.2)As the direction of the tower crane changes,the vertical load is not distributed uniformly among the two bearing beams of the lower-level structure;however,the difference is little.The worst condition of supporting structures is that the crane direction of the large boom and the direction of the supporting beam are orthogonal.As for an attachment wall,the worst condition is that the crane direction of the large boom and the direction of the supporting beam are parallel to each other,and under this condition,there are internal forces in the same direction of the supporting structure,and these forces brought by the vertical load and the horizontal load will lead to deformation.3)The force transmission is clear,the bracket and the embedded parts own a higher-level strength reserve,and the strength of supporting beams are satisfied by the design requirement,the additional horizontal stand bar of the high-level supporting system is able to undertake 15%-20% vertical load.4)In actual detection,the section deformation of supporting walls satisfies the plane cross-section assumption,and the effective width is around 2.0 times of the width of the embedded part.In that case,the effect of the tower crane load to exterior walls outside 2.0m from the edge of the embedded part is very little.When the tower crane is climbing or lifting,the vertical load is bigger than the dead load,and the lifting coefficient is about 1.10.5)The internal force of tower crane's supporting system achieves the climax at the top level.Make the lifting weight max,if the thickness of supporting wall reduces to 300 mm,the reinforcement ratio needs to be the same as the walls with the thickness of 400 mm,and the lifting weights also have to be limited to 50 t.All the above are the conclusions that we got from experiments and analysis.They can provide not only experience for the design of attachment wall in similar engineering,but also references for the technical specification of high-rise building.