Explosive compaction: design, implementation and effectiveness

Abstract

Although used for over 70 years, Explosive Compaction (EC) has not attained widespread acceptance despite the attraction of low cost and ease of treating large depths. Lack of familiarity with the method, and an empirical design approach unrelated to theory, appear the primary cause for reticence in adopting EC. To alleviate these concerns, practical design considerations for EC based on detailed experience from nine applications and trials are presented here to illustrate the predictable and repeatable effectiveness of EC. Design is based on cavity expansion theory. EC readily gives volume changes 2–3 times larger than might occur under large earthquake motions, with final average relative densities often greater than 70%. Further, environmental and vibration control issues do not constrain the use of EC provided that appropriate explosives and delayed detonation sequences are used. As pronounced post-blast time effects are evident in penetration testing, evaluation of the effectiveness of EC should be based on a combination of pre- and post-blast penetration testing and volume change measurements.