Page 515 - Rock Mechanics For Underground Mining

DISCONTINUOUS SUBSIDENCE ASSOCIATED WITH CAVING METHODS OF MINING

Figure 16.10 Schematic representa-
tion of the surface subsidence result-
ing from block caving, and associated
definitions.

inclined surface slopes forming only in weak or weathered surface layers. However, a
number of features of the orebody and the local geology and topography can influence
the extent of the surface expression of caving. These factors include (Brown, 2003):
the dip of the orebody;

the shape of the orebody in plan;

the strength of the orebody;

the strength of the surrounding country rock;

the strength of the overburden or cap rock;

the presence of major structural features such as faults and dykes intersecting the

orebody and cap rock;
the depth of mining as defined by the undercut level and the associated in situ

stress field;

Figure 16.11 Plan view of the sub-
sidence crater at the El Teniente Mine,
Chile, in 1998 showing the Braden
Pipe and the locations of several
production sectors (after Karzulovic
et al., 1999).
497