Performance And Application Research Of Nested Steel Tubular Scaffold

With the rapid development of national infrastructure, the steel tubular scaffold is widelyused in engineering practice. Due to its characters of assembled and disassembledconvenience, saving time and effort, high security, reliability and effectiveness, the nestedsteel tubular scaffold has been applied in several projects. So far the nested steel tubularscaffold with high practicality has reached domestic advanced level, which has become keypromoted project of scientific and technological achievements in construction industry inGuangdong province. For further promotion and application, it is really necessary to carry oncomprehensive and systematic study on this new kind of steel tubular scaffold, thus to providetechnical support for the design work.The article focuses on the nested steel tube fullframing system. It has carried on a seriesof experimental study and finite element analysis, and the main contents and results aresummarized as follows.1. For the purpose of obtaining the rotational stiffness of nested node under positive andnegative moment action directly, two groups of tests were designed. Numerical simulationanalysis is conducted with FEA method, and the results of which were compared and verifiedto actual test results. The stress distribution of nested node under positive and negativemoment action was also analyzed, thus to evaluate the weakest position.2. Three groups of lateral stiffness tests was proceed to compare the lateral resistancecapacity of nested steel tube full framing system with or without diagonal brace and fastenersteel tube full framing system with diagonal brace. Then evaluate the action of diagonal braceand verify the superiority of nested steel tubular scaffold. The FEA model of whole formworksupport was established based on rotational stiffness, and the analysis results and test resultswere compared thus to verify the reliability of calculating model.3. Four groups of bearing capacity tests was proceed. Corresponding FEA model foreigenvalue buckling analysis and nonlinear static analysis was also established. Through thecomparative analysis, failure modes and bearing capacity of formwork support varied with liftheight of1.2m and1.8m were analyzed.4. The effects on bearing capacity of full framing system under different spacing ofstanding tube and different forms of diagonal brace were evaluated with a series of FEAanalysis, and the effective length factor corresponding with lift height of1.2m and1.8m weredetermined respectively. 5. Special construction program of nested formwork support system for a building inGuangzhou is established in this article. It also can provide some reference for design,calculation and construction of practical engineering.The research results could provide related experimental data and theoretical basis forcompiling Technical Specification for Safety of Nested Steel Tubular Scaffold in Construction.It also can provide some reference for design of nested steel tubular scaffold.