Research On The Mechanical Performance And The Whole Construction Process Of Cable-supported Grid Structuer With Internal Compression Ring

The cable-supported grid structure,as an emerging hybrid spatial structure with rigidity and flexibility,is derived from the spoke-wheel-type prestressed system.There are three ways to balance the horizontal force of the radial cable in the cable-supported grid structure:(1)by the upper grid;(2)by the external compression ring;(3)by the internal compression ring.Therefore,cable-supported grid structures can be divided into three types.The first two structural forms have been extensively practiced in domestic and foreign projects.In this paper,the roof structure with an internal compression ring of Shanghai Pudong Football Stadium,is taken as the engineering background.The mechanical properties and key construction techniques of the structure have been studied.The specific research contents and conclusions are as follows:Firstly,the principle of cable-supported grid structure is introduced.The stress characteristics of structures with different force balance modes of radial cables are analyzed respectively.Meanwhile,the form-finding analysis,structural performance,construction technology research and typical engineering application of cable-supported grid structure are described in detail.The background project,Shanghai Pudong Football Stadium,is introduced,including project overview,design ideas,structural characteristics,load and boundary conditions,materials and specifications of members.Secondly,the author analyzes the main factors that affect the forming state of the cable structure after construction.A new force-finding method with self-balanced prestress for whole structure and whole construction process is introduced.The contents of the method include the following aspects: according to the design configuration,establish a model including temporary construction components;conduct iterative analysis,and perform non-linear analysis sequentially and continuously during an iteration,including zero-state condition and construction process conditions;update the prestress of the structure;iterate analysis until the forming state meets the convergence condition.Then,based on the determined construction steps,the force-finding analysis is carried out for Shanghai Pudong football stadium roof structure according to the above method mentioned.The results of the zero state form-finding analysis and the whole construction process analysis have reached the expected goal.Next,the mechanical properties of the cable-supported grid structure with internal compression ring are studied,including static performance,stability performance and natural vibration characteristics.The static performance analysis includes three parts: the effect of prestress levels,reliability analysis on serviceability limit state and ultimate limit state.The load conditions are composed of dead load,live load,wind load and temperature effect.Stability analysis includes eigenvalue buckling analysis and nonlinear buckling analysis considering initial defects,with full-span and half-span live load conditions.In the analysis of natural vibration characteristics,the load case with the dead load is selected to obtain the various modes of the structure.After that,the joint structures and construction technologies of Shanghai Pudong Football Stadium are systematically introduced,including the material properties of cast steel joints,tension joints of the radial cables,cable clamps,upper and lower joints of the V support,etc.The lifting and installation methods of the cable net,the selection of tensioning tools are also introduced.Finally,a systematic summary of the main research contents and results of this paper is presented,and the unsolved problems and further research directions are proposed.