Rectangular Tank Seismic Load Calculator | ACI 350.3-06
Calculate seismic design forces for rectangular liquid-containing tanks per ACI 350.3-06. The calculator separates the liquid mass into impulsive and convective components, determines corresponding seismic coefficients, and computes wall pressures and base shear. Input tank geometry, liquid properties, and site seismic parameters for a complete load determination.
Impulsive mass moves rigidly with the tank wall during an earthquake. Convective mass sloshes near the free surface. ACI 350.3 treats them separately because they respond at different frequencies.
What tank types does this cover?
Rectangular liquid-containing tanks such as water treatment basins, wastewater tanks, and industrial process tanks. For circular tanks, a different procedure applies.
Does it calculate freeboard for sloshing?
Yes. The calculator determines the convective wave height so you can verify whether the tank has adequate freeboard or if the roof must be designed for sloshing impact loads.