Preliminary Study Of Designe Method Of Steel-Concrete Composite Slab

Slab is very important to the bridge, the working conditions of which will affect heavily the behavior of the bridge in service. The exiting slabs made of asphalt concrete tend to appear longitudinal cracking, wave process, local folding, web cracking, and so on, which will affect the performance of the whole bridge. The steel and the concrete composite slabs adopted in a great deal in the buildings have very excellent mechanical behavior and the economic benefit of them has been proved early, too. The composite slabs were used in the bridges and the effect was very good. But they are still not popular in our country, the cause of which is lack of the research data about the mechanical behavior of the composite slabs, and less attention was paid to the research of the design code. Moreover, the design method of the composite slab is from foreign codes.Because of all of above mentioned, this thesis is to discuss the several aspects about composite slabs. Firstly, discuss the effective width of the slabs with various boundary conditions, and study the difference of the effective widths which are gotten in different standard, discuss the merits and shortcomings of the exiting design code for the moment, more attention is paid to the research on the mechanical behavior of the composite slab applied in one/two or more than two loads. Secondly, study the distribution of the support reactions when the composite slabs bear various loads, and discuss the methods of calculating the effective width for shearing design; explore the effective width of the composite slab applied in several loads in which the effective widths of the loads overlap each other. Thirdly, due to the contradiction between the linear calculation of the effective width and the section design in which the assumption of all materials reaching their ultimate strength is adopted, nonlinear analysis is carried to analyze the material nonlineatity influence on the effective width. Fourthly, the model of the cellular girder and the composite slab is built by use of software ANSYS. Calculate the effective width of the composite slab in one or more loads and compare the data got above with the value from the formula of the code to find the similarities and differences. At last, analyze the cantilever slab and try to get some conclusions. Recently, less research on the slab was done, especially in our country less research was found; the conclusions of this thesis can give theoretical reference to engineers or researchers engaged in the bridge design or interested in the further research on the composite slab.