Research On Mechanical Properties Duting Construction Stage And Temperature Field Of Steel-concrete Composite Structure Bridge

In the modern bridge engineering, steel-concrete composite structure has become an important bridge structure besides the reinforced concrete structure and the steel structure. Steel-concrete composite structure bridges are widely applied to bridge construction in China along with the constant maturity in aspect of calculation theory and design method about steel-concrete composite structure. At present, the research on the steel-concrete composite structure bridge mainly concentrated on the calculation method of design, experimental research of basic theory, structure improvement, etc. Relatively few of study on performance in it’s construction process can been seen. Therefore, the research on the performance of construction process has practical significance for the realization of the popularization and economic value of steel-concrete composite bridge.Combining with the engineering example, experiment is conducted to study the mechanical properties of the construction stage and temperature field of a steel-concrete composite bridge. The main contents and conclusions were shown as follows:(1) Development of steel-concrete composite structure are described briefly, the characteristics of steel-concrete composite structure are introduced, the present situation and the insufficiency of related research fields are discussed.(2) Through the numerical simulation of the whole construction process of the bridge, the stress characteristics of girder on the construction phase was studied, while the actual stress state of the composite beam was tested using the stress test element. The stress state of the steel-concrete composite beam was evaluated by comparing the theoretical analysis and the measured data.(3) Through the finite element numerical simulation, the dynamic characteristics of the steel-concrete composite bridge in the construction stage was studied. And then, the application of modal parameter identification in bridge construction monitoring was researched by the way of measurement.(4) In order to study the temperature field and its effect of steel-concrete composite girder bridge,taking the actual project of a steel-concrete composite girder bridge as the research object, its temperature field is measured. The most disadvantageous temperature gradient mode along the vertical section of the steel-concrete composite girder is obtained by the least square fit(LSF),and it is contrasted with the temperature gradient mode stipulated in the current specification of China.Finally,the bridge structural responses under the action of two kinds of temperature gradient modes are analysed by the established finite element model of the real bridge.