STUDY AND CALCULATION OF STEEL STRUCTURE SCHEMES FOR A LARGE EXPERIMENTAL TANK ABOVE GROUND

Being aimed at a requirement to construct a large steel water tank containing 22 500 tons above ground, Sereral schemes were proposed. Through the analysis and comparisons of multiple schemes, the steel structure scheme of the tank was determined:the main structure was composed of trapezoidal cross section truss columns, multiple horizontal waist trusses and multiple capping trusses. The wall of the tank was made of continuous supporting arc-shaped steel plate to form a tension structure, which could effectively resist the effect of hydrostatic pressure and reduce the thickness of the steel plate. During the construction process, the trapezoidal cross section truss columns were first installed, then pre-tension was applied on the top of the truss columns and the cables were temporarily anchored, after that the horizontal waist trusses and capping trusses were installed, and finally the cables were removed and the curved wall plates were installed. This cable-free prestress scheme could make the internal force of the truss columns after the structure installed and the bending moment generated by the hydrostatic pressure cancel each other out, greatly reducing the stress level of the steel structure in normal use. On this basis, the dynamic characteristics of the overall steel structure tank and the main process load effects (wave-making, high-speed entry), etc. were studied. Based on a fluid-structure coupling analysis model of the tank, the time-history response of the seismic motion was studied. Finally, the hole opening scheme for the wall plate and numerical analysis results, as well as the design scheme of the foundation were given.