Anatomy of Failures: Stability Requirements in All Stages of Operations

¹ Ph.D, PE, NAE, Senior Fellow, Principal Engineer, Exponent; Adjunct Professor, Stanford University
² Ph.D, PE, SE, Managing Engineer, Exponent Inc., Atlanta, Georgia, USA

^* Corresponding author, moncarz@exponent.com

Abstract

The paper provides examples of how temporary conditions experienced during construction, retrofit, or repair can bring an otherwise robust structure to failure. The KTVO Tower near Kirksville, Missouri, USA, guyed by seven tiers of guy cables, stood 610 m tall, until it suddenly collapsed on June 2, 1988. The collapse occurred during the replacement of potentially defective braces. The Tower had been subject to severe weather conditions, as well as having previously lost some braces; and yet, the experienced repair company brought it down through altered brace replacement employed by the repair crew. How did it happen? This paper goes through all the stages of this tragic event; from the failure scene back through failure analysis to the design, manufacturing, material supplies, and fatally altered repair procedure. This paper also provides an example of reinforced concrete structures which are erected with the steel reinforcement delivered to their final position as a multi-story cage lifted in-place by crane and acting as temporary independent structures. Their stability relies on proper bracing and restraint. What if some of the bracing becomes an obstacle to some activities? The paper concludes with best practices for involving a licensed professional at all stages of construction or repair in order to help prevent future collapses.