| With the rapid development of China ’s construction industry,all kinds of high,new,strange large complex buildings have been unprecedented development,high-formwork as a temporary support system in the construction process of these buildings has also been more and more used.In recent years,the socket type disk buckle formwork support frame,which is famous for its simple structure,quick removal and recycling,has been widely used.Some cities have also issued relevant policies on plate-type scaffold.However,at present,there are few researches on the socket type disk buckle formwork support system at home and abroad,which will undoubtedly affect its further promotion.Therefore,based on the comprehensive development project of the canopy cover of a high-speed railway station,this paper studies the socket type disk buckle high-formwork system in the project construction.The main research contents and conclusions are as follows :(1)Based on the analysis of the collapse accidents and causes of high-formwork in recent years.And the research status of high-formwork system at home and abroad,the current research status and shortcomings in the field of high-formwork are summarized,and the research content and direction of high-formwork system are determined in this paper.The related concepts and theories of high-formwork system are sorted out,and the calculation models of various formwork support systems are compared.The connection characteristics of high-formwork frame joints are analyzed.Combined with the stability theory of high-formwork and the Euler formula of axial compression members,the appropriate calculation method is selected,which lays a theoretical foundation for the stability study of the subsequent socket type disk buckle high-formwork system.(2)Based on the comprehensive development project of the canopy cover of a highspeed railway station,starting from the overall deployment and design of the high-formwork system,the stress of the high-formwork system is theoretically calculated.The strength,stiffness and stability of the 1000 mm × 2400 mm section beam formwork and 200 mm floor formwork are designed and checked,and all meet the requirements.The finite element software SAP2000 is used to establish a high-supported model under the beam.The finite element analysis of the stability under three different working conditions is carried out,including eigenvalue buckling analysis,Bucking analysis considering P-Δ effect and nonlinear stability analysis,and compared with the theoretical calculation.The ultimate bearing capacity is 59.113 k N,58.825 k N and 56 k N respectively,which is greater than the maximum stress value of the vertical pole calculated by theory 51.274 k N,and is very close to the ultimate load calculated by theory.The gap between the results of nonlinear analysis and theoretical calculation is the smallest,which is more practical.It also proved that the design scheme of the formwork support frame is reasonable,feasible and safe.Then,SAP2000 was used to establish a 9-span × 7-span × 6-step high-formwork model to further study the stability of the socket type disk buckle high-formwork system,and to explore the influence of the structural parameters of the frame on the stable bearing capacity.The finite element model was used to adjust the structural parameters of the frame,and the influence of various factors on the stable bearing capacity of the socket type disk buckle highformwork system was analyzed.The results show that the stable bearing capacity can be improved by properly adjusting the horizontal bar step and vertical bar spacing of the socket type disk buckle high-formwork structure system.(3)Through the relevant accident cases,literature and standard screening methods,the influencing factors of the safety of the high formwork system are identified.After the combination and arrangement,the factor analysis is carried out by the questionnaire survey method,and the four dimensions of material quality,design scheme,site construction and safety management are completed.The safety evaluation model of high-formwork system is constructed,and the fuzzy comprehensive evaluation method is selected to analyze and evaluate the safety of the socket type disk buckle high-formwork system.Through the combination of qualitative and quantitative methods,the safety of high-formwork system of a high-speed railway station canopy comprehensive development project is systematically and comprehensively evaluated.The results of fuzzy comprehensive evaluation showed that the safety evaluation result of the high-formwork system of the project is 86.46,the safety level is excellent,and the safety evaluation results of each level index are also greater than85,reaching an excellent level.According to the results of safety evaluation,combined with the engineering practice,the construction safety assurance measures of high-formwork support system are put forward from four aspects : material quality,design scheme,site construction and safety management,so as to reduce the probability of accidents,ensure the safety of people ’s lives,provided safety guarantee for the smooth progress of the project and avoid economic losses.Figure [61] Table [42] Reference [88]... |
