Probabilistic Limit State Design Method Of Composite Steel-Concrete Beam Bridges

Based on domestic and foreign relevant specifications, documents and experimental results, through comparing and analyzing to the existing formulas analyzed according to the plastic theory, the basic formulas that this thesis is used in statistical analyses of resistance force of structure component of composite beam bridges are determined.According to the indirect method of statistical analysis of resistance force of structure components, statistical analyses to 3 main factors influencing resistance force of structure components are separately presented. Firstly, statistical parameters of indeterminacies of material behavior and statistical parameters of that of geometry parameters are determined, that influence resistance force of structure components of composite beam bridges; to the indeterminacy of calculating mode, this thesis collects 62 groups of composite beams test results and 125 groups of push out test results of two failure models of stud connectors .On the basis of these test data and statistical calculation, statistical parameters of indeterminacies of calculating mode of flexural capacity of composite beams and that of shear capacity of stud connectors are given.Take the first cross section as an example, and the calculation formula of flexural capacity of composite beams is obtained by using the error transfer formula of mathematical statistics. According to this formula, calculation formula of shear capacity of stud connectors and statistical parameters of 3 main factors influencing resistance force, statistical parameters of flexural capacity of composite beams and that of shear capacity of stud connectors are separately proposed on the basis of calculating and analyzing.On the ground of statistical parameters of flexural capacity of composite beams, that of shear capacity of stud connectors and that of dead load and traffic load effect of highway bridge, the first order second moment method is used to calculate the partial safety factor of resistance force corresponding to 2 combinations for action effects, and limit state design expressions of flexural capacity of composite beams of highway bridges and that of shear capacity of stud connectors of composite beam bridges are determined.