Seismic monitoring offers the best insight into current rock mass damage process and failure related to mining-induced fault reactivation. Brittle failure can be recorded in real-time as seismic events. This paper explores the relationships between geological structure and mining-induced seismicity through real time monitoring in an area called sanshandao mine, with concentration on the 645 level. Geological features within Sanshandao mine have a reported association with seismic activity, 406 orebody shear zones were identified during field investigations, the most prominent striking SW and steeply dipping NW. Seismicity from 2013.11 - 2014.4 is analysed, Spatial and temporal trends and seismic event parameters show little correlation to shear zone geometry. Instead, seismic event parameters correlate to spatial clusters of events.
Seismic monitoring offers the best insight into current rock mass damage process and failure related to mining-induced fault reactivation. Brittle failure can be recorded in real-time as seismic events. The degree of damage in a rock mass can have a dramatic effect on the properties of the seismic waves emitted from microseismic sources, notably on wave velocity and attenuation (Feustel 1998). Such changes have been used to describe the rock mass character. Lower velocity and higher attenuation is recorded in a heavily fractured rock mass as compared to a homogeneous and unfractured rock mass (Jiang 2003). Given this, it is expected that the state of damage in the rock mass would also have a noticeable effect on source parameters, most of which are calculated directly or indirectly from the recorded waveforms. Temporal trends in seismic event parameters can approximate loading curves similar to those traced in acoustic emission tests (Coulson & Bawden 2008). Such curves indicate that at the point of fracture initiation, the moment magnitude, seismic moment, seismic energy and apparent stress increase until the point of yield, at which point fractures coalesce and there is a significant drop in parameter values (Coulson & Bawden 2008). Spatial and temporal analysis of microseismic event parameters was conducted to identify trends and assess rock mass properties on level645. Temporal analysis of levels and clustered events on the 645 Level did not reveal any significant trends but did reveal comparable spatial event distributions: dense seismicity extends from the southeastern corner of the excavation to an area southwest of the excavation Figure 1. Events in this area occur sporadically during the half-year time period. It is postulated that in the Sanshandao Deep the micros seismic event distribution as well as the event parameters reflect both local stress conditions and the physical state of the rock mass.
