Investigation the effect of top stiffening ring on the buckling capacity of thin-walled steel storage opened-top tanks subjected to local settlement

Thin-walled steel storage tanks are used for an extensive array of engineering applications such as urban resource water, petroleum industry, and nuclear power plants for storing variety of liquids, e.g. water, gas, and petrochemicals. The ratio of the radius to the thickness of these tanks is about 5 00to 0000, and the height to radius ratio is about 0.5 to 0.0.The support beneath the tank may lose the bearing capacity in some areas, with the primary reason for this being geometrical misfits, poor soil conditions, ununiformed applied load. Additionally, foundation unevenness, change of ground topology, and foundation subsidence beneath a steel tank can all lead to the development of support settlement of tanks, with tank support settlement being variously categorised as uniform settlement, tilting, and local settlement. After compacting the substrate, these tanks are supported on a concrete foundation using a concrete ring. Thin-walled steel tanks are used in various industries to store oil and gas condensate. These tanks are supported on a concrete foundation by compacting the substrate. This foundation may lose its load-bearing capacity and settle in a part of the reservoir foundation due to non-uniform geometry or improper soil compaction under the foundation or uneven distribution of load applied to the foundation. Possible settlements are including a uniform, tilt of plan and non-uniform. Non-uniform local settlement is one of the most common and destructive types tanks settlement. In this study, the effect of local settlement on the buckling capacity in the tank with and without stiffening ring was investigated in laboratory and numerical. The results showed that the stiffening ring has an effective role in increasing the parameters of toughness, maximum equivalent load and initial stiffness. It increases the toughness by 98%, the maximum equivalent load by 58% and the initial stiffness by 101%. The presence of stiffening ring also plays a very important role in controlling radial displacements. As by preventing the radial displacement of the upper edge increases the buckling and post-buckling capacity of the tanks.