Mechanical Analysis And Application Of High-support Formwork For Large-span Polyline Arch Structure

The disc buckle steel tube high support formwork is a multi-span,multi-layer space frame composed of a variety of members such as rods,bases and top supports.The frame body is connected and fixed by a disc-shaped buckle plate and a caliper wedge pin.The disc buckle scaffolding is a new type of scaffolding.It has the characteristics of fast installation speed,reliable connection of nodes,good overall space effect,high accuracy,and convenient construction.It has been widely used in the construction field.Although the disc-type steel tube high-support formwork support system has been widely used in large-span,singular-shaped buildings(structures),the socket-type disc-type high-speed support formwork is used in large Folding arch-type support structures are few and their research theories are relatively few.In view of the above reasons,relying on the municipal road project of the east Yansha River section of Hongqi Avenue in Ganzhou City,this paper intends to carry out research on the large-span broken-line arch tunnel structure disc-type steel pipe high-support formwork system.The purpose of the research is to compare and analyze the effect of the rigid and semi-rigid node assumptions on the mechanical properties of the high-support formwork system.comparative analysis.The key research process includes:(1)Monitoring the change data of the stress of the disc-type scaffolding rod with the construction process,and grasping the changing law of the supporting structure stress with the construction process.(2)On the basis of considering the rigidity and semi-rigidity of the support nodes,the finite element software is used to establish the disc-buckle steel pipe template model,and the finite element analysis results,monitoring data and manual calculation theoretical results are comprehensively analyzed.The main research contents and conclusions of this article are as follows:(1)By referring to the cases of scaffolding safety accidents in China,the cause analysis of the accidents is summarized,and the experimental and theoretical research status of high support templates at home and abroad is introduced.(2)The design structure,support performance characteristics and calculation theory of the socket-type disc-type high-support formwork are described.Considering the semi-rigid characteristics of the socket-type disc-button high-support formwork nodes,the mechanical performance and research methods of rigid,hinged,and semi-rigid nodes are compared,and the M-? characteristics of semi-rigid nodes are summarized.(3)Finite element software was used to establish the finite element model of the socket-type high-support formwork with the assumption of rigid and semi-rigid node models,respectively,to provide a basis for the selection of the scheme.Through comparative analysis of the displacement and internal force calculation data of the two node models,the results show that the semi-rigid node model is more in line with the actual situation.(4)On-site monitoring of high-support formwork of long-span broken-line arch tunnel.By analyzing the monitoring data,the stress variation rules of the horizontal and vertical rods during construction are obtained.Comparing the theoretical calculation with the monitoring data and finite element analysis data,the results show that the high-support formwork considering the semi-rigid connection of the nodes is more in line with the actual conditions.