STATIC BEHAVIOR OF BURIED REINFORCED-CONCRETE MODEL CYLINDERS,
 Technical Report R606, Naval Civil Engineering Laboratory, Port Hueneme, CA, by J.R. Allgood and H.G. Herrmann, III, January 1969, 50 pages.

Experimental results and empirical relations are given which define the behavior of reinforced-concrete model cylinders that are buried in dry sand with their longitudinal axis parallel to the surface. The model cylinders were 9 inches in outside diameter and had a single layer of reinforcement at midsection. Thickness, percent reinforcement, and depth of cover were varied. The 12 test cylinders cracked at uniform surface pressures of less than 60 psi and subsequently deformed in such a way that the ratio of the effective stiffness of the cylindrical inclusion to the stiffness of the soil in the vertical direction remained constant.

Significant moments were induced that would preclude the design of buried cylindrical shelters on the basis of the pure compression mode. The magnitude of the induced moments increased with increasing wall thickness and increased at a decreasing rate with increasing load.

Empirical relations which agree reasonably well with the test data are given for permitting estimates of horizontal expansion, arching, thrust, moment, and interface pressure.