Concrete Deep Submergence Hollow Shell Structures

Experiments of an exploratory nature have been conducted with 34 spherical concrete shell models of 16-in. OD and 14-in., 12-in., 10-in., and 8 in. ID to determine what potential concrete shells have for application as pressure hulls in deep submergence ocean bottom habitats with one atmosphere internal environment. Parameters investigated were the relationship of spherical shell thickness to the critical pressure of the shell, its permeability, strains, and tolerance to stress concentrations. The magnitude of hydrostatic pressures used in imploding the spherical shells varied from 2,000 psi to 14,000 psi, depending on shell thickness, type of hydrostatic loading, and condition of concrete. The generated test data supports the hypothesis that concrete is an acceptable material for spherical external pressure hulls applicable to permanent ocean bottom habitat construction.