Research And Design Of Jacking Steel Platform Moulding System For Super High-rise Building

With its high load-bearing capacity,fast construction speed and high safety performance,the jacking steel platform formwork system（referred to as jacking mould）has become a mainstream construction tool for the construction of vertical walls in the core of super tall buildings.In the actual project,the top mold is not widely used because of its conservative design and low turnover rate.Therefore,applying the modular design to the top mold design is one of the effective methods to solve the above problems,which can effectively improve the installation accuracy and security of the top mold,and achieve the purpose of cost reduction.In this paper,we study the jacking steel platform formwork system and combine it with an example of a supertall building on a Suzhou construction and the relevant design of the jacking moulding,the main work is as follows.（1）The system structure,advantages and disadvantages of hydraulic mold frame technology（i.e.sliding mold,climbing mold and top mold）used in current construction projects are sorted out and analyzed,and the advantages of top mold in super high-rise building construction are derived,and the system composition,working principle and construction process of top mold are elaborated.（2）Taking a super high-rise building as the background,the design of jacking steel platform moulding system is carried out with the characteristics of the project building.The results show that the internal force of vertical web of triangular joist is smaller and the arrangement is more economical in terms of material consumption,and for the overhanging end and primary joist,it is appropriate to use double diagonal webs.For overhanging end and primary joist,double diagonal web joist is preferred to enhance the stability of the member.（3）Using modular design method,the modular design study was conducted on the key system of the jacking die,in which the angle between the truss chord and web is preferably controlled from 45° to 55°.Six standard sections of the key system of the jacking die were established for design selection,and three different arrangement schemes of the key system of the jacking steel platform were designed at the same time,and analysis of them were carried out for various options of design.The three-design solutions were statically stressed and flexural analyzed by finite element analysis software,and the stress clouds,displacement contour diagrams and stress ratio folding statistical diagrams under different working conditions were obtained,and the most reasonable design solution was derived after comparison and analysis.（4）Based on the determined initial design scheme,the cross-sectional dimensions of the members of the key system of the jacked steel platform were optimized by the stress ratio using the principle of controlling a single variable.The optimized solution was subjected to finite dimension verification analysis,and the results showed that the optimized cross-sectional solution met the requirements of the design and had the advantages of lighter self-weight and more reasonable structural forces,thus reducing the material waste caused by excessive safety reserves.In this paper,on the basis of satisfying the structural rationality and economic applicability,the research and design of the jacking steel platform moulding system is carried out,and the design ideas of the system are sorted out,and the reliability of the design is verified,so as to provide some reference value for the industrialization and promotion of the jacking moulding construction technology in the construction industry.