Large volume tanks

Claim 1

A cylindrical storage tank of the type having a circular bottom plate attached at its circumference to a cylindrical wall extending perpendicularly upward from the plane of the bottom and comprising a series of ring courses of uniform thickness attached at their edges to adjacent ones of said courses, wherein the improvement comprises: a. a support band secured about the lowest of said courses at a point where the radial deflection is greatest as defined by the equation, w/poR2/ETo To/T1 ( 1 - BZ/BL - e BZ (cosBZ +Mp Sin BZ) ) + Z/L Where: Z Distance up tank wall from tank bottom w Radial deflection outward po Radial pressure outward at the bottom R Tank radius E Young''s Modulus To Calculated thickness of unstiffened bottom course T1 Actual thickness of bottom course L Combined height of courses requiring reinforcement v Poisson''s ratio B (3(1-v2))1/4/ square root RT1 Mp (plastic hinge moment of tank bottom plate X 2B2/po b. at least one additional support band secured about a ring course above said lowest course and thinner than said lowest course, the number of said bands being between 0.7 (he - hb)B and (he - hb)B, Where: he height of the tank where the actual and calculated thickness are equal hb height of the band of (a).