Title: Concrete Cylinder Structures Under Hydrostatic Loading
Author(s): Harvey H. Haynes and Bjorn A. Nordby
Publication: Journal Proceedings
Appears on pages(s): 87-96
Keywords: buckling;cylindrical shells;hulls (structures);hydrostatic pressure; implosions;limit design method;loads (forces);oceans;offshore concrete structures;shells (struc-tural forms);stability;strength;stresses;structural analysis;structural design; thickness.
Several design equations are presented to predict implosion of thin-walled and thick-walled concrete cylinder structures under hydrostatic loading. Of significance is the development of a modified Donnell equation to analyze moderately long, thin-wailed cylinders for implosion. Most concrete structures for offshore oil production platforms fall in this category. Donnell’s equation is modified by an empirical plasticity-reduction factor which varies from 1.0 to 0.10 for cylinder wall stress at implosion that vary from 0.4 fc' to 1.1fc' respectively. For P long thin-walled cylinders, a modified Bresse equation is used. For short cylinders, Lame’s equation is used where the cylinder wall stress at implosion is 1.1 fc'. For thick-walled cylinders, an empirical equation is presented. In a section on design for hydrostatic load, these equations are presented using the ultimate limit-state design approach.