Title: Behavior of Reinforced Concrete Cylindrical Shells Subjected to External Hydrostatic Water Pressure

Author(s): Amr I. I. Helmy and Michael P. Collins

Publication: Structural Journal

Volume: 113

Issue: 5

Appears on pages(s): 1031-1042

Keywords: circular slab; cracks; cylindrical shells; hydrostatic pressure; reinforced concrete offshore structures; underwater structures; water flow

DOI: 10.14359/51689025

Date: 9/1/2016

Abstract:
Laboratory equipment was designed and implemented to study the effect of water pressure on reinforced concrete structures. They included a pressure vessel, a video monitoring system, and a pressurizing system. Then, the hydraulic testing facility at the University of Toronto was brought into operation. The facility is capable of testing model offshore structures under high water pressure. A one-seventh-scale model of a buoyancy compartment of a small offshore oil platform was designed and constructed as a pilot specimen. Two pilot tests were carried out using the same pilot specimen to study its behavior. The failure water pressure was approximately three times the design pressure. At failure pressure, a major circumferential crack in the cylindrical shell near the slab-shell connection was formed. At this pressure, uncontrollable water leakage through large concrete cracks associated with steel yielding occurred. The concrete in compression was capable of preventing water flow through concrete cracks until the steel yielded. Post-yielding capacity of a section was unreliable in preventing water flow.