Research On Load-bearing Performance Of Super-large Socket-type Wheel Buckle Steel Formwork Support

As a new formwork structure system developed to meet the demands of large space,large span and large self-weight structure,the socket type steel tubular formwork bracket has been widely used in engineering practice because of its advantages of simple structure,convenient construction and large bearing capacity.However,the structural design theory,the overall bearing capacity,the application of construction safety technology and other related studies are relatively lagging behind,which has seriously limited the popularization and application of the system.In order to have a deep understanding of the mechanical behavior and construction performance of tubular formwork supports with socket buckles in engineering practice,and to determine their stable bearing capacity,this paper conducted a series of studies by means of field tests,finite element simulation and theoretical analysis.The main research contents and results are as follows:(1)Through a total height of 23.28 m,length,width 7.2 m of ultra large socket round buckle type steel pipe formwork support structure stress performance test,verify the ultra big socket round buckle type template support overall stability under normal conditions,the measured under the normal working condition of displacement condition and different types of key parts of the template support bar stress values,and on the basis of the analysis summarizes the ultra large socket round buckle type steel templates support the basic rule of stress.(2)Based on the automatic control theory,a set of outdoor high-altitude water automatic loading control system was developed,and the system was applied to the mechanical performance test of tubular formwork support with socket type wheel buckle;(3)Through a total height of 11.28 m,length,width 3.6 m tall socket round buckle type steel pipe formwork mechanical performance test,studied the tall socket round buckle type steel pipe formwork 3 times under normal working load on the bearing performance,analysis under large eccentric loading have been socket round buckle type steel template stent displacement situation and basic rule of the different parts of the different types of bar stress(4)The advantages in construction performance of tubular formwork brackets of socket type wheel buckle type and fastener type were quantitatively compared and analyzed by means of setting up tests of tubular formwork brackets of socket type wheel buckle type and fastener type.Through the ultra large socket round buckle type steel template framework in the form of build-up test verifies the feasibility of this structure,authors,and templates support build-up in the process of the problems are analyzed and discussed,and put forward the corresponding technical requirements,for the socket type wheel button of writing and improvement of the steel pipe formwork application specification provides guidance.(5)Through the finite element software ANSYS to establish the super big and tall socket round buckle type steel pipe formwork structure model to simulate the field test by the unloading process,form scaffolding full intuitively got two template scaffold model under various load of the beam displacement deformation,stress distribution and overall with the test results,this paper compares and analyzes comprehensively summarized socket round buckle type steel pipe formwork the basic rule of stress:1)The vertical bar in the socket type wheel buckle type steel pipe formwork bracket is the main stress bar,and the stress of the intermediate bar is greater than that of the side bar and the Angle bar;The maximum stress of the same vertical bar may occur at the top or at the bottom,and the top is more sensitive to the load;2)The horizontal bar in the socket type wheel buckle steel pipe formwork bracket is mainly stressed to restrain the deformation of the vertical bar,so its stress state is extremely complex.However,the force on the top or bottom bar is often larger than other positions,and the bar at the same height,the closer to the load,the greater the force,and vice versa;3)The vertical scissor brace and the horizontal scissor brace in the socket type steel tube formwork bracket are also stressed to restrain the deformation of the whole frame,and the stress basically increases with the increase of load,which plays an important role in the stress of the whole frame and the constraint of the overall deformation;4)The sweeping rod in the large steel tube formwork bracket of socket type wheel buckle has obvious stress,which not only participates in the stress of the whole frame,but also,more importantly,improves the overall stability of the frame;(6)Finally,on the basis of summarizing the basic theory of calculating the stable bearing capacity of formwork supports,the common calculation models and calculation methods are discussed,and the advantages and disadvantages,application scope and practicability of each method are analyzed.In focus on probability limit state design method,on the basis of in-depth analysis of socket round buckle type steel pipe formwork mechanical characteristics,puts forward the solving socket round buckle type steel pipe formwork stability bearing capacity of the consideration of shape coefficient of fixed length calculation method,and gives the shape coefficient of the specific values as well as the modified computing formula for computing the length.