Research On The Stability Of Composite Steel Plate Girder Bridge With Medium-small Span In Completion Process

With the development of society,economy and highway traffic,there are more and more researches and applications of medium-small span composite steel plate girder bridge.Stability is one main point of the design of steel and composite structure.However,there are only formula about the overall stability of simply supported beam and the regulations of flakiness ratio and height-to-thickness ratio in the current specifications.Therefore,it’s very important to research the stability of composite steel plate girder bridge with medium-small span.Based on 3×35m double-girder composite steel plate girder bridge of the relying engineer,the elastoplastic entity models were established by ABAQUS finite element software.The stability safety factor is used as evaluating indicator for parameter analysis about the stability safety of composite steel plate girder bridge with medium-small span,which is to get corresponding rules and some optimization suggestions in design from stability.The main work of the paper includes:(1)This paper systematically introduces the modeling methods of stability analysis by ABAQUS,and verifies the correctness of the methods with the experimental data in literature.At the same time,it studies the relationship between the stability safety and the number of spans.Based on the results,it determines that the paper studies the 3×35m double-girder composite steel plate girder bridge.(2)For the stability safety of 3×35m double girder steel plate composite straight girder bridge,a variety of parameters are selected to carry out parameter analysis.As result,the reasonable spacing of crossbeams and the reasonable values of height-span ratio and widththickness ratio of compressed flange are put forward.Orthogonal test was designed to study the influence of multi-factor coupling on stability safety and steel consumption of the whole bridge,and the significant factors were pointed out.What’s more,a reasonable reference model was given by synthesizing the two indexes.(3)For the stability safety of 3×35m double girder steel plate composite curved girder bridge,several parameters are selected for parameter analysis.The reasonable spacing and height-span ratio of beams are put forward.And the formula of elastic critical moment of simply supported curved girder is derived.The relationship between the stability safety performance of structure and curvature radius is studied from both theoretical analysis and finite element calculation.Orthogonal test was designed to study the influence of multi-factor coupling on stability safety and steel consumption of the whole bridge,and the significant factors were pointed out.What’s more,a reasonable reference model was given by synthesizing the two indexes.(4)This paper introduces three kinds of construction techniques commonly used in composite steel plate girder bridge with medium-small span,and carries out modelling the representative working conditions,and evaluates the corresponding stability and safety performance.In the end,from the point of stability safety,the paper recommends the reasonable one.