Full‐scale experimental and theoretical investigation on wall stress for underground ecological group tanks with four‐circle tangential connections

The storage safety of edible oil is critical for global and Chinese food security. In this study, a practical underground four‐circle tangential group tank with the steel‐plate and concrete structure based on a grain storage warehouse was firstly introduced, and the measured hoop reinforcement stress of the outer tank wall is discussed. Secondly, a numerical model consistent with the practical underground group tank is established from the measured data. The distribution of the hoop reinforcement stress of the outer tank wall under earth pressure is extracted and analyzed thoroughly. Finally, formulas reflecting the properties of the hoop reinforcement stress distribution are presented based on the theoretical analysis, and their accuracy is verified by comparison with the measured data. It could be conducted from the experimental results and theoretical formulas that the outer tank wall is under compressive pressure station generally, and the compressive stress increases with the increasing of the ring angle until reaching a steady state. Moreover, the hoop stress curve follows a disproportional function approximately. The moment at 180° hoop with 1‐m plate belt follows the arc‐tangent function while the moment has a sudden‐change point at 120°, which has minor effect on the reinforcement of this tank wall. Consequently, additional attention should be paid to the effects of this sudden‐change phenomenon on the associated structures in in the process of designing of underground storage tanks.