| Concrete-filled steel tube tied arch bridges are widely used in the construction of large and medium-span bridges because of superior performance and beautiful shape.In this paper,based on the reliability assessment of the ultimate state of the bearing capacity of the tied arch bridge in engineering practice,based on the analysis of the mechanical properties of the tied arch bridge and the basic theory of structural reliability,the function of the tied arch bridge under the limit state of the bearing capacity is highly nonlinear and It is impossible to express explicitly,which leads to the problem that the conventional reliability analysis method is difficult to accurately solve the structural reliability.The reliability analysis method and application of the tie-bar arch bridge under the limit state of the bearing capacity are explored.Main points of this paper are as follows:(1)Based on the related research results of the stress characteristics and reliability theory of tied arch bridges,the difficulties in the analysis of the reliability of the ultimate state of the tied arch bridge are discussed,and the ultimate state reliability analysis of the bearing capacity of the tied arch bridge is clearly defined.The problem that should be solved,determine the goal,content and method that need to be studied.(2)Analyze the mechanical performance of the tied-arch bridge structure system,define the force characteristics of each major load-bearing component,and give expressions of the resistance of each component according to the relevant bridge specifications,and establish the ultimate capacity of each component on this basis.Under the function function.Based on the reliability evaluation of the main force components of tied arch bridges,the PNET method is used to simplify the failure system of tied arch bridges,and the equivalent series system of tied arches is established to form the structural system reliability assessment method for tied arch bridges.(3)Through the analysis of conventional reliability calculation methods to solve the reliability of the tied-arch bridge,the weighted average simulation method is applied to the calculation of the reliability of the limit state of the bearing capacity of the tied-arch bridge,and the reliability analysis program is compiled using MATLAB software.A simple example verifies the feasibility and accuracy of the program.(4)ANSYS software is used to establish the finite element model of real bridge,and the random variables that affect the reliability analysis of the example tied-arch bridge are determined.The reliability of the ultimate state of the bearing capacity is analyzed by the weighted average simulation method.The PNET method is used to simplify the failure mode of the example tied-arch bridge,and based on the reliability index of the components,the ultimate state reliability of the bearing capacity of the structural system is analyzed.(5)Based on the reliability theory and the weighted average simulation method,combined with the analysis and calculation of engineering examples,the ultimate state reliability analysis method and process calculation method for the bearing capacity of tie-bar arch bridges are formed,and the ultimate state reliability analysis method for the bearing capacity of steelconcrete-concrete tied-arch bridges is formed.And based on the calculation and analysis results,it provides reference for the related design and operation and maintenance of tied arch bridges. |
