Geology Reference
In-Depth Information
RQD
(range 0-100%)
Step 1: field data
Refer to table 10.2
RMR
(range 0-100)
Hoek Brown
(
m
)
Hoek Brown
(
S
)
Step 2: Calculate
Refer to table 10.3
Rock mass
tensile
strength
Rock mass
compressive
strength
Figure 10.15
Flow diagram summarising the stages involved in calculating the
compressive and tensile strength of a rock mass from field data. Colour relates
to equation in Table 10.3.
governs the geotechnical properties of a rock mass in response to deformation
and its hydraulic properties. The RQD, RMR and ultimately the compressive
and tensile strength of the rock mass can be assessed using the simple steps out-
lined here. If the stresses acting on igneous rock mass are altered in some way,
either through man-made activities such as drilling or construction, or through
magmatic activity (inflation of magma chambers inside a volcano or intrusion of
sills and dykes), then the rock mass can lose integrity and fail. If the rock mass
happens to be an active volcano, then the consequences may be severe indeed.
