Performance Research Of Wheele-coupler Type Steel Tubular Scaffolding

With the prosperity of the construction industry,the application of scaffolding is becoming increasingly extensive.As a new type of scaffolding,wheele-coupler type steel tubular scaffolding has many advantages,for example,multiple functions,high efficiency,and greater bearing capacity.However,due to the lack of in-depth research and insufficient technical specifications,the employment of wheeled steel scaffolding is largely limited.Therefore,it is of great significance to study the structure and performance of the wheele-coupler type steel tubular scaffolding,as well as to formulate local standards for Guangdong province by compiling the document Technical Specificantion for Safety of wheele-coupler type steel tubular scaffolding(DB 44/T 1876-2016).Promotion of this new type of scaffolding enables its design and construction method to be standard,so as to improve economic and social benefits.The present study examines the wheele-coupler type steel tubular scaffolding with cross bridging to investigate a seires of issues through in-depth experiment and finite element analysis,i.e.its safety performance,resistant-lateral rigidity,Equivalent diagonal bracing rigidity,and the influence of various erection parameters on the bearing capacity of the template support frame.Two site prototype tests for five-meter-high wheele-coupler type steel tubular scaffolding were carried out,from which the load-strain curve and load-displacement curve of the frame are obtained.Furthermore,the structural characteristics of the wheel support frame are obtained based on the trend of curve.Two tests of the wheeled steel scaffolding’s performance and its anti-lateral stiffness were conducted,from which the ultimate bearing capacity,failure mode and load-displacement curve of the frame are obtained.A comparative analysis shows the superiority of wheeled cross bridging over the coupler ones.Results of the comparative test and the finite element analysis show that the major factors that lead to the different ultimate bearing capacity and the lateral stiffness might be attributed to the defects and displacement deviations in the connection of different cross bridgings.Therefore,a method is proposed which uses equivalent spring stiffness to reduce the negative effect of joint gaps on the coupling stiffness of cross bridging.The finite element model is obtained by the equivalent stiffness parameter analysis.Considering the Equivalent diagonal bracing rigidity,the ultimate bearing capacity of the wheeled steel scaffolds with cross bridging is analyzed.Various factors that may excert an influence on the ultimate bearing capacity of the frame were explored,such as cross bridging plane arrangement,cross bridging space arrangement,distance between upright poles,space between upright poles,the quality of the material and the initial bending of the bar.According to the results of finite element analysis,suggestions for the actual project are put forward,which provides important reference for the compliling of standards.The test results show that the hoisting steel pipe scaffolding possess good bearing capacity and stability,which can meet the requirements of the high support template system and provide important reference for the compling of the standard.