Rock Mechanics Project progress and results: rock fracture and pore collapse

Effect of simultaneous and sequential detonation on explosive-induced fracture

“…There is, however, a possibility that the use of medium delays to orient fractures in a geologic seam without creating undeslred damage elsewhere might be worthwhile. The lack of any increase of damage with delay disagrees with the simple computer experiment described at the beginning of this paper [15]. The disagreement is apparently because the fractured plastic does not act as a continuum with degraded wave impedance.…”

“…This interaction could produce tensions, and therefore enhance fragmentation. This concept has been verified by a simple one-dimensional computer calculation [15]. Unfortunately, in such a calculation the rock is treated as a continuum.…”

Seismic monitoring: a unified system for research and verifications

“…The few comparisons of calculations with experimental data have used parameter adjustment to compare with close-in data [Cherry and Petersen, 1970]. Presently researchers are not able to descirbe the details of motion resulting from explosions with this code without parameter adjustments [Schatz et al, 1977]. The calculations require a prohibitive amount of time, and hence no complete finite-difference calculations exist from the source region to distances where the seismograms are recorded.…”

“…1966aSpringer. , 1966bSpringer ei al., 1968], and finite-difference calculations of the near-source behavior of explosions [Butkovich, 1965;Rogers, 1966;Holzer, 1966;Cherry, 1967;Cherry and Hurdhw, 1966;Cherry and Petersen, 1970;Schatz et al, 1977]. Within this period of time there has been considerable effort in developing empirical models for seismic-source function [Murphy and Mueller, 1971;McEvilly and Peppin, 1972;Aki, 1967;Ah et al, 1974;Randall, 1964Randall, , 1971Backus and Mulcahy, 1976], on discrimination of earthquakes and explosions [Liebermann and Pomeroy, 1969;Marshall, 1970;Evernden ei al., 1971: Marshall andBasham, 1972;Douglas et al, 1974], and on magnitude relations asa function of geo physical properties of the earth [Marshall ei at., 1978;Chung, 1978].…”

Inelastic Processes in Seismic Wave Generation by Underground Explosions

“…Shear stresses can also cause dilatation of a compacted material under increasing hydrostatic pressure. These effects are illustrated in model for shear-enhanced compaction (Schatz et al 1977), but the improved accuracy in modeling this aspect of rock deformation was not deemed to be worth the large increase of computer time required for a typical problem. SOC73 uses relations between hydrostatic pressure (P) and volumetric strain (AV/V) that are based on laboratory measurements of stress and strain in rock samples.…”