models of this report and provided the stress-strain curve of the material 
used has the same shape as those for inelastic failure design illustrated 
ine bisurce as. 
ACKNOWLEDGMENTS 
The author acknowledges the technical assistance of Messrs. Martin 
A. Krenzke and Robert F. Keefe and the contribution of Mr. Pendleton E. 
Humphries who conducted the hydrostatic tests. 
