Study On Force Analysis And Construction Optimization Of The Bridge Deck Support System In Steel Plate-truss Composite Cable-stayed Bridge

Orthogonal profiled steel deck truss composite cable-stayed bridge applys to the construction of large-span mountain highway because of the structure has the feature of light weight, stiffness, strong capability across, driving comfort.Thus it is applied to span freeways at home and abroad, the large-span bridges and rail-cum-bridges more and more. So far, there is no refined Terms and conditions work for orthogonal profiled steel deck truss composite cable-stayed bridge in China.It needs a further study on this kind of structure.This paper established a spatial finite element model of orthogonal profiled steel deck truss composite cable-stayed bridge to analyzed in detail about the mechanical behaviors of main board truss structure factor of the combination plate girder composite system. Subsequently, a balance equation is established using the deformation compatibility conditions in which the each board truss member connecting lines at the location of the beam, further deduced expressions plate girder lines connecting internal force distribution relationships. Meanwhile, by changing parameters to analyze quantitatively the objective factors influence on the force behavior of the system.After that, according to the above-mentionedstudy of the force behavior of plate truss composite system, optimize its structure, and by comparing the results of the finite element analysis, verify the correctness and availability of this structural optimization method.Thesis research results show that the middle stringers to top chords force deliveringratio with the middle stringers, small stringers, the top beam, the second beam section stiffness showed a positive relationship, however, with the top chord section stiffness and deck beams disposing spacing showed an inversely proportional relationship.And force transmission ratio of small stringers and top chords, and the beam, secondary beam section stiffness showed a positive relationship, with theupper chord, the middle stringers, small stringer section stiffness and small deck beams disposing spacingshowed an inversely proportional relationship.In consideration of the limited beam-plane stiffness conditions, using the deformation compatibility conditions of the beam place---- the each truss connecting plate tie rods-----can be established equilibrium equations in order to deduced the longitudinal load force delivering ratio of each segment of the plate truss composite structure of each component.Iterative analysis of this force transmission ratio canoptimize the plate girder link system effectively.What' s more, it makes the force of truss composite components in the whole bridge more reasonable and becomes higher efficiency.