Trabajo presentado en el VII Simposio Peruano de Geoingeniería.

Por: E. Trujillo, J. Ames, A. Ambros, F. Calixto y S. Meyer.

Abstract

Seismic monitoring at the Cerro Lindo mine in Peru has detected nearly 6,500 events in and around the coverage area over a one-year monitoring period. The vast majority of events are small and do not represent a major hazard; however, some events have been of significant magnitude. 

These occurred mostly near mining areas and are associated with an increase in the level of stresses locally linked to a dike. Most of the significant events occurred near void spaces (workings or mining zones) and had crushing type mechanisms (convergence) and vertically oriented P axes (indicative of maximum principal stress). 

Smaller events with shear-type mechanisms occurring within the dike itself are also observed and are interpreted as episodes of sudden fracturing without volumetric change of the dike. These indications and the stress modeling, which shows a high value of the maximum static stress level index in the zone of greatest influence, support the hypothesis that the dike plays a major role in the stress field in this zone and in the occurrence of the seismic events that caused damage.