| With the development of bridge construction in China,the support system is an indispensable part of bridge construction.However,at present,there are some problems in the support system in China,such as insufficient theory,design defect and inaccurate calculation,which lead to the instability and collapse of the support system in the process of bridge construction.In order to ensure the stability of the support system,this paper makes an in-depth study on the stability of the steel-belay beam support system from the theory to the construction technology,and finally puts forward reasonable Suggestions on how to control the stability of the support system in the construction according to the research results.Based on the support system of cast-in-situ steel and concrete beams of the main span of the road bridge south of chongqing central park as the engineering background,this paper mainly studies and analyzes the following problems:(1)Based on the theory of stability,the stability of the support system is analyzed by balance method and energy method.The key technologies and key points in the construction of the steel tube column-bele beam support system are described in detail.(2)According to the type of compression member in the supporting system of steel pipe string and bele beam,the stability of two kinds of equal-section compression members is analyzed.In this paper,the instability problem of the equal-section pressure bar with linear change in axis is analyzed and solved numerically under two different supports(two ends hinged,two ends hinged and an elastic support in the middle of the bar).(3)In this paper,the static equilibrium method and the energy method are used to analyze the instability problem of the hinged intermediate struts,and the results show that the energy method is more accurate.(4)Using the finite element software ANSYS,the model of single steel tube column and the supporting system model of steel tube column and bele beam are established.The results are compared with the theoretical analysis values to verify the theoretical analysis results.(5)By changing the element attribute and structure size of the finite element model,the influence of transverse wind load,step distance,pole spacing,joint stiffness and initial defect on the lateral stiffness and stable bearing capacity of the support system was discussed.(6)Through theoretical analysis and finite element analysis,it can be concluded that the elastic support can be set up in the middle of the steel tubular column and bele beam to increase the critical bearing capacity of the member.The step distance,pole spacing and joint stiffness have a great influence on the stability bearing capacity of the steel tubular column-berei beam support system. |
