The Unique Source Mechanism of an Explosively Induced Mine Collapse

Technical Report · Wed Dec 31 04:00:00 EST 1997

DOI:https://doi.org/10.2172/618160· OSTI ID:618160

Mining explosions and collapses, in addition to earthquakes, may trigger the future Comprehensive Test Ban Treaty (CTBT) monitoring system. Most naturally occurring mine collapses have source mechanisms similar to a closing void which might provide a physical basis to discriminate them from explosions. In this study, an explosively induced mine collapse is investigated. The collapse occurred immediately after the support pillars of an underground mine opening were destroyed by explosives. We estimated the time-dependent source moment tensor of the collapse by inverting the surface ground motion data ({lt}1200 m). The results indicate that the source mechanism of the collapse can be represented by a horizontal crack. A unique source characteristic of the induced collapse is that, unlike natural collapses, the induced collapse initiated as a tensile crack. Because of the initial expansion source mechanism, induced mine collapses may pose some difficulties to the seismic discrimination problem. On the other hand, the collapse has a more band limited source spectrum than a typical underground explosion.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 618160
• Report Number(s): LA-UR--97-2645; CONF-970967--; ON: DE98000601; CNN: Contract W-7405-ENG-36
• Country of Publication: United States
• Language: English

Related Subjects

35 ARMS CONTROL
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
BLAST EFFECTS
EXPANSION
EXPERIMENTAL DATA
GROUND MOTION
MATHEMATICAL MODELS
MINES
MONITORING
NUCLEAR EXPLOSION DETECTION
SEISMIC DETECTION
SURFACES
TENSILE PROPERTIES
TENSORS
TIME DEPENDENCE
UNDERGROUND EXPLOSIONS