Research On The Failure Mechanism Of Wheel-buckled Steel Pipe Supporting Formwork System

Wheel-buckled steel pipe supporting formwork is a new type of steel pipe supporting formwork system,which has been applied to many practical projects because of its advantages of high work efficiency,low cost,strong adaptability and clear transmission path of force.However,due to the fact that the research on the wheel-buckled steel pipe supporting formwork system in China is in the primary stage and no unified national standard has been issued,the system is restricted in many regions,which has a certain restriction on the popularization and development of this new technology.Therefore,in order to promote the development of the wheel-buckled steel pipe supporting formwork system and provide the basis for the formulation and revision of relevant technical standards,this thesis takes the wheel-buckled supporting formwork system as the research object,researches the failure mechanism of the system and the influence of structural factors on the failure of the system,and the relevant contents are as follows:(1)Using ABAQUS finite element analysis software,the finite element model of the wheel-buckled supporting formwork system is established,and the elements of the model establishment and the application mode of the load in the frame are determined.The failure mechanism of the wheel-buckled steel pipe supporting formwork system is explained from the overall bearing capacity and overall stability of the supporting formwork.(2)Through the finite element models of 23 wheel-buckled supporting formwork system,the distance between vertical poles,the distance between horizontal poles,the height of sweeping poles and the length of the free end of vertical poles on the stable bearing capacity of the frame are quantitatively analyzed.The influence of height-to-width ratio of the frame on the stable bearing capacity of the frame is qualitatively analyzed.According to the value of stable bearing capacity,the law of influence of each parameter on the stable bearing capacity of the supporting formwork is obtained,and structural measures are suggested.(3)Through finite element simulation,this thesis researches the influence of different erection methods of vertical scissor braces and horizontal scissor braces on the stable bearing capacity of supporting formwork.Through the finite element models of 9 wheel-buckled supporting formwork system,the influence of different combinations of vertical scissor braces arranged in the four side elevations of the frame on the stable bearing capacity of the supporting formwork is analyzed,and the variation law of the stable bearing capacity of the supporting formwork with vertical scissor braces only with length-to-width ratio of the frame body is obtained.Through the finite element models of 9 wheel-buckled supporting formwork system,the influence of choosing different parts in the bottom,sub-bottom,middle,sub-top and top of the frame on the stable bearing capacity of the supporting formwork is analyzed when the horizontal scissor braces can only be set in one horizontal layer,and the variation law of the stable bearing capacity of the supporting formwork with horizontal scissor braces only with height-to-width ratio of the frame body is obtained.According to the results of the research,some suggestions are given on the erection methods of vertical scissor braces and horizontal scissor braces in the supporting formwork system.