The Research Of New Sliding Construction Technology For Large Span Steel Structure

With the development of large-span steel roof structure, steel structure sliding construction technology is increasingly applied. Based on the status quo of sliding construction with multi sliding track, several new sliding construction technologies aiming at decreasing the usage of steel and enhancing the overall stability of the temporary support as well as lowering the cost of construction are proposed and researched.The main content and research findings are as follows:1. The summarization of basic theory of sliding construction is made, and the calculation model of sliding construction is proposed in this paper. Based on the method of element birth and death of local configuration constraint, the sliding construction project example has been simulated with ANSYS. The results of computation have agreed with its actual measured values well in the project, which validates that the finite analysis model and the method are correct.2. Based on the strength design of the falsework, unbalanced support sliding construction technology for bidirectional beam string structure is proposed and analyzed. The new technology which has broken through conventional method that tensile force generally is applied to the cable after sliding construction being totally finished. The analysis results showed that the temporary supports of middle sliding track can be weakened when imposing appropriate pre-stress on cables during construction, thus the steel usage of temporary supports and the foundation below can be decreased, and finally the costs of sliding construction can be reduced.3. Imitating the fact that imposing appropriate pre-stress on cables during construction can reduce the vertical load on middle temporary support in bidirectional beam string structure, the paper put forwards a new sliding construction technology for steel truss structure, arch camber downward sliding construction, which is to reduce the middle vertical reaction forces by blocking up the mid-span slide-way with base plate, and welding steel trusses and finally removing the plate. The analysis results indicate that the new technology can realize the goal. On the contrary, as for structures whose middle temporary support is relatively strong while bilateral coupling beams weak, arch camber upward sliding construction is proposed. The analysis results show that by blocking up the bilateral slide-way with base plate, welding steel trusses and then removing the plate before sliding, vertical reaction forces of bearing at both ends can be reduced, and thus strengthening scale and costs can be reduced.4. Based on the stability design of the falsework, by analyzing effective length which is determined by end restraint conditions, optimization design methods of middle temporary support are given, and three types of end constraints are discussed and summarized. The analysis results indicate that the optimization design methods can improve the stability of structure.The new technology of sliding construction for large span steel structure discussed in this paper is feasible in theory and it will be highly applied to the large span steel structure installation, economizing manpower and material resources and creating economic benefits.