Behavior of Welded Steel Water-Storage Tank

The performance of a recently constructed welded steel water-storage tank, believed to be the largest of its kind in the world, is monitored for thermal and live-load (internal pressure) strains during initial filling. The experimental investigation and data are presented, along with an evaluation of the performance of the tank. Also presented for comparison to the measured stresses are predicted hoop and meridional stress distributions for approximate theories of cylindrical shell behavior. A finite element model using axisymmetric solid elements is used to account for the effects of nonuniform wall thickness and to model base restraint. Differences in predicted and analytical stresses are discussed. Differences due to unknown base restraint are observed and explained. Other observed differences, generally indicating conservative design procedures, are not conclusively explained, but two possible explanations are presented, including residual fabrication stresses and systematic measurement errors.