Study On Design Parameters Of Corrugated Steel Plate-UHPC Composite Bridge Deck With PZ Composite Dowel Shear Connector

The orthotropic steel bridge deck is prone to fatigue cracking and steel bridge deck pavement diseases,so the relevant research in this paper is specially carried out to deal with this phenomenon.Starting from the idea of optimizing the structural form of steel bridge deck and improving the deck pavement materials,the structural system of corrugated steel-UHPC composite deck with PZ composite dowel shear connector is established.In this structural system,corrugated steel plate is used to replace the flat steel plate-closed rib,which is more popular in orthotropic steel bridge deck,so as to reduce the number of discontinuous parts and welds and reduce the risk of fatigue failure of bridge deck from the source.UHPC concrete is selected as the rigid base at the top of corrugated steel plate,and the composite bridge deck can have light weight and better overall stiffness and mechanical properties under the synergistic force of steel and concrete.In order to ensure the reliable connection of steel-concrete interface and enhance the section stiffness,the PZ composite dowel shear connector with excellent mechanical properties and convenient construction is used as the shear connector.The mechanical properties of the composite bridge deck formed by the combination of the three are to be studied.This paper mainly focuses on the optimization design of structural parameters of corrugated steel-UHPC composite bridge deck with PZ combined pins through the finite element analysis method,and analyzes the static performance of the optimized composite bridge deck under positive bending moment.The research contents of this paper are as follows :(1)The technical requirements of orthotropic steel bridge deck and concrete pavement are combed,and the structural form and the initial value of design parameters of the composite bridge deck are determined.Through the single parameter influence effect analysis,the important design parameters affecting the structural performance and their value range are clarified.Through the analysis,the law of the force performance control index changing with the parameters on the focus is determined,the force performance index which plays the control role is clarified,and the range of the parameters is further reduced.(2)The full parametric model of corrugated steel-UHPC composite bridge deck was established and the sensitivity analysis was carried out.46 groups of experimental design points were generated by CCD sampling method.Finally,the structural response surface model meeting the accuracy requirements was obtained by fitting,and the influence of different parameters on the performance level of composite bridge deck was visualized.By comprehensive utilization of multi-objective genetic algorithm,three sets of Pareto solutions of composite bridge deck are obtained.After screening from many aspects,the optimization results are obtained.Analysis of the changes before and after the optimization goal shows that the optimization effect is good.(3)The fine simulation model of the composite bridge deck was established to study and understand the stress change,strain distribution and UHPC damage change of the whole composite bridge deck and its components under positive bending moment.The shear span ratio,diaphragm spacing and concrete strength are selected as influencing factors to analyze their influence on the bearing capacity of bridge deck.(4)Based on the finite element analysis,the theoretical analysis of the composite bridge deck is carried out,and two kinds of bending bearing capacity formulas of the corrugated steelUHPC composite bridge deck are derived.The overall stiffness of the composite bridge deck is calculated by the conversion section method,and the deflection calculation of the composite deck in the elastic stage is completed.The results show that the theoretical calculation value is consistent with the finite element results.