A Study of Selected Rock Excavations as Related to Large Nuclear Craters

Book excerpt: Analogies between nuclear and conventional excavations are developed from a tabulation of data from 153 mine, quarry, roadway, and dam excavations. The following factors were used as the basis for tabulation of conventional excavation data: purpose, location, precipitation, temperature, ground water level, lithology, mass strength, structural pattern, slope plan, slope profile, depth of excavation, slope height, average inclination, and stability. It was found that average slope inclination tends to be greatest for hard material and for material lacking a well-developed structure, and that inclination tends to de- crease with increasing slope height for excavated slopes reported to be stable. The authors conclude that good analogies are to be found in shape, slope height, depth of excavation, and slope inclination. Loadings of waste material at the rim of some open pit mines may be analogous to ejecta on the lips of nuclear craters. Rubble zones found in some open pit mines may be analogous to the fallback zones of nuclear craters. Differences between preshot and postshot characteristics of cratered media must be appreciated in evaluating analogies between features of conventional excavations and preshot features of nuclear excavation sites. Brief descriptions of 21 selected excavations are presented in Appendix A. The results of this study serve as an aid to judgment of nuclear crater slope stability. Potential subjects for further study are identified.