Analysis Of Strength And Stability Of Flat-bottom Squat Steel Silos Strengthened With Circumferential U-steel

Ground-supported steel silos, which are mainly used for the storage of granules, powder and so on, are now widely used in agriculture, mining, electricity, metallurgy, chemical engineering and other fields. Compared to traditional storages, silos have such advantages as smaller covered areas, higher capacity and easier operations etc.As a kind of revolved combined thin shell structure, steel silos possess rather complex behavior and failure criteria under load. What is more, the failure of the structure may cause immeasurable loss due to the lack of design guidelines which could correctly reflect the mechanics characteristic of steel silos. Nowadays, the destruction ratio of steel silos has become the highest among that of all kinds of structures. Because of the existence of large vertical friction and normal pressure at the bottom of steel silos, some steel plates at the bottom are the first to yield, which causes a lot of rigidity loss and excess radial displacement, and then leads to structure failure that prevents the silo from being used normally. As for those steel plates with defects, the cause of their failure may be the obvious reduction in bearing capacity.Until now, the most common strengthening technology in steel structure is still welding reinforcement, which means welding some metallic components in the parts where the load is large or reinforcement is needed in order to enhance or recover the bearing capacity of structure. This technology applies to steel silos too, and the method is to weld vertical or circumferential stiffeners like U-steel and T-steel etc on the interior or exterior of the silo wall. It has been proved by practice that these measures are effective in improving the bearing capacity and extending the service life of steel silos.This thesis carries out static analyses, linear buckling analyses, geometrical non-linear buckling analyses and geometrical material bi-non-linear buckling analyses on a practical steel silos storing cement under both conditions where there are circumferential stiffeners and where there is no stiffener in the interface of Adina8.8.Through these analyses, a conclusion can be made that welding circumferential T-steel stiffeners at the bottom of steel silos where there is large load is effective in reducing the stress and radial displacement in the reinforced areas and enhancing the bearing capacity of steel silos. By comparison, it is more effective to weld the stiffeners in the center of the reinforced steel plates, and the bearing capacity of steel silos increase with the rise in the size of the stiffeners. In conclusion, it may obviously reduce the stress and displacement by welding circumferential stiffeners at the bottom of steel silos.