Estimate of residual shear strength around explosion cavities in earth media : Terhune, R W; Glenn, H D Proc 19th US Symposium on Rock Mechanics, Stateline, Nevada, 1–3 May 1978, V1, P130–136. Publ Reno: University of Nevada, 1978

Abstract

A method to determine the residual shear strength of the fractured rock surrounding an explosion has been developed using measured or inferred cavity radii. After passage of the initial shock wave, the residual shear strength of the fractured rock controls the subsequent motion of the rock and the residual stresses that can reduce permeability. Numerical computer codes that model the explosion phenomena are used to develop the functional relationship between the normalized cavity displacement and the normalized shear strength of the rock. In this sense, the computer models serve the role of a replica model to which dimensional analysis is applied to interpret the field experience. The effects of gravity and overburden pressure are separated from the effects of the material properties, and scaling laws for each are given. The analysis is applied to approximately 300 nuclear explosions at the Nevada test site in a variety of rock types. The shear strengths predicted from cavity radii agreed well with those from numerous laboratory measurements on core samples. 27 references.