Research On Key Technology Of No-support Construction Of The Annular Cable-bearing Grid Structure

The annular cable-bearing grid structure is composed of supporting structure,upper single-layer grid and cable-strut system.There is a large opening space in the middle of the upper single-layer grid of the annular cable-bearing grid structure,which is suitable for the stadium building.The traditional method of installing the support and then tensioning the cable is still used mainly at home.However,the non-support construction method is used in overseas projects.Non-support construction method can save a lot of support costs and construction period.Therefore,the application of non-support construction method has broad prospects.This article is based on Qatar Education City Stadium as the engineering background and research on key construction techniques of non-support construction of the annular cable-bearing grid structure,it mainly includes structural characteristics,form-finding analysis,lifting analysis,analysis of tie-down,analysis of the whole construction process and analysis of the influence of construction errors on the structure.The specific research contents and conclusions are as follows:Firstly,the author introduces the basic composition,mechanical characteristics and application status at home and abroad of the annular cable-supported grid structure,and expounds the basic construction process of two different construction methods for similar structures traditional construction method and non-support construction method.The author introduces the project of Qatar Educational City Stadium in detail,including the engineering background,structure composition,material specifications and joint structure,as well as the whole process of ANSYS modeling.Finally,the accuracy of ANSYS model is confirmed by comparing the results of ANSYS model with the design results(GSA).The author expounds the overall non-support construction process of Qatar Educational City Stadium.Focusing on introducing the analysis theory of the nonlinear dynamic finite named NDFEM,it includes analysis process and key technical measures.Then using this method to carry out the form-finding analysis of cable-net construction of Qatar Educational City Stadium and get the status of cable-net laying on the stand and the initial length of lifting cables.Two key problems are studied in the construction process in this paper,lifting of cable-net and tensioning tie-downs.By synchronous lifting cable-net in equal proportion,it is found that the deformation of CR is too large and there is torsional overturning trend of CR,and then optimization analysis of cable-net lifting is carried out to determine reasonable lifting scheme.By synchronous tensioning tie-downs in equal proportion,it is found that the deformation of CR is too large.According to the analysis results,the tension sequence of tie-downs is optimized and the reasonable tension scheme of tie-downs is determined.According to the general process of non-support construction and the construction conditions of Qatar Educational City Stadium,the detailed construction sequence is made.The detailed analysis of the whole process is carried out to obtain the structural response under each condition.Meanwhile,comparing the final results with those of one-step analysis,the difference is very small,which reflects the rationality of construction sequence.Considering the actual production assembly error,the construction process is analyzed.Comparing with the analysis results of construction process without considering the influence of errors,the results are similar,which shows that the actual errors are effectively controlled.Finally,this paper summarizes the major research contents and achievements systematically and put forward the unsolved problems and further research direction.