Model Test And Theoretical Research Of Orthotropic Steel-concrete Composite Bridge Deck System Based On The Integration Of Pavement

Orthotropic steel-concrete composite bridge deck system based on the integration of pavement is a kind of bridge deck system which paves an asphalt wearing layer on the concrete rigid base on the orthotropic steel bridge deck. It can not only ameliorate the static and fatigue performance of steel bridge deck, but also eschew damage of steel bridge deck pavements, such as cracking and debonding and etc.. Therefore, these superior performances promote the application of this new type deck system. The static performance of this composite bridge deck system was investigated via a full-scale model experiment. At the same time, the parameters analyses and fitting were carried out for this deck along with the influence analyses of rigid bases using the Finite Element Method(FEM). Finally, the theoretical analyses of this novel system was conducted. The main research work of this thesis is shown as follows:(1) The performances of composite deck structure and complex pavement structure were compared, and the structural requirements of the orthotropic steel-concrete composite bridge deck system were summarized. In addition, six control indices of this deck system were put forward based on the outlines and cause analyses of the fatigue of orthotropic steel decks and the disease of steel deck pavements. The six indices comprise the maximum tensile force of concrete rigid base σct, the maximum tensile stress of asphalt layer σat, the maximum interfacial shear stress between rigid base and steel roof τ1, the maximum interfacial shear stress between rigid base and asphalt layer τ2, the maximum mises stress of steel roof σd, and the maximum mises stress of welding hole σh.(2) A full scale model experiment of orthotropic steel-concrete composite bridge deck system was conducted. The stress values of the structure under different load conditions were tested respectively with three construction stages, which were bare orthotropic steel bridge deck, steel-concrete composite bridge deck formed by laying the lightweight concrete ridge base and the steel-concrete-asphalt composite deck system after pouring of the asphalt wearing layer. Then the finite element analyses were also carried out.(3) The single-parameter and multi-parameter analyses of the orthotropic steel-concrete composite bridge deck system were carried out using FEM. The influences of six design parameters on each control index of this system were studied respectively. Then, an orthogonal test plan was designed using the orthogonal test theory, the linear correlation equations between each control index and the six design parameters were obtained by multivariate linear regression analyses of the test results respectively, and then the significance and factor analyses of each design parameter on the control index were conducted.(4) The influences of the rigid base on the displacement and stress values of several stress points of orthotropic steel-concrete composite bridge deck with closed and open stiffening rib were analyzed using FEM. Of these, the influence of the rigid base on the stress concentration factor of the composite bridge deck with U-rib stiffened was analyzed via the sub-model method. Additionally, the effects of thickness and elastic modulus of rigid base on this novel system were investigated.(5) The theoretical analyses of the orthotropic steel-concrete composite bridge deck system were carried out. The calculation formulas of longitudinal and transverse bending bearing capacity and interface shear stress of the intersection of positive and negative moment regions were derived for this deck system. Furthermore, comparative analyses and parameter analyses were conducted on some typical bridges.