AWWA ACE95143

This paper tells of experiences concerning how steel elevated water storage tanks performed during the Whittier, Loma Prieta, and Northridge earthquakes. In general, the steel elevated tanks evaluated performed very well, in that none of them fell or lost water. The tanks reviewed in this paper were all multiple column, strut and diagonal bracing type tanks. Modes of failure noted were all readily explainable, and are classified as: failure to design ductility into the structure--no enlarged portion of diagonal bracing where threaded (no upsets); discontinuities in diagonal bracing; inability of horizontal struts to accommodate yield loading in diagonal bracing; inadequately designed connections, single shear, unbalanced doubled-shear, cotter key retainers, failure to design for yield loads; and improper anchorage, anchor bolts, anchor chairs, shear keys. The authors conclude that a sensible approach to increasing seismic survival probability includes anchoring the tank to take advantage of the maiximum downward holding force of the foundation, designing the diagonal bracing to yield before the anchor bolts yield, connections fail, or the struts buckle.

Product Details

Published:

01/01/1995

ISBN(s):

0898678358

Number of Pages:

7

File Size:

1 file , 290 KB