The tank in an empty state along with a high groundwater table can experience severe uplift on the floor slab. In this example the groundwater table is then 3′ + 1.17′ above the bottom of the 14″ thick slab. The approximate dimensions of the slab are 60′ × 20′. The slab will be designed as a one-way flexure member spanning in the short direction. Consider a 1′ wide strip of slab with an ultimate load wu from the water pressure below the slab.