Civil Engineering Reference
In-Depth Information
China (Chen, 1995a,b). As would be expected,
if the slopes were not selected according to geo-
logy, there is little correlation between slope
height and angle for stable slopes. However,
sorting of the data according to rock type
and rock strength shows a reasonable correla-
tion between slope height and angle for each
classification.
Figures 1.6 and 1.7 is to encourage the use
of consistent terminology that can be clearly
understood by others in the profession when
investigating and reporting on rock slopes and
landslides.
1.4 Rock slope design methods
This section summarizes four different proced-
ures for designing rock slopes, and shows the
basic data that is required for analyzing slope
stability.
1.3 Slope features and dimensions
The International Association of Engineering
Geology has prepared definitions of landslide fea-
tures and dimensions as shown in Figures 1.6
and 1.7 (IAEG, 1990; TRB, 1996). Although the
diagrams depicting the landslides show soil-type
slides with circular sliding surfaces, many of these
landslide features are applicable to both rock
slides and slope failures in weak and weathered
rock.
The design methods and the design
data
are
common
to
both
mining
and
civil
engineering.
1.4.1 Summary of design methods
A basic feature of all slope design methods is that
shear takes place along either a discrete sliding
surface, or within a zone, behind the face. If
the shear force (displacing force) is greater than
The value of the definitions shown in
19
B
A
9
8
7
6
B
1
2
A
4321
8
19
14
A
A
3
4
16
5
20
15
6
17
18
5
10
B
B
11
Figure 1.7
Definitions of landslide dimensions:
upper
portion
, plan of typical landslide in which dashed line
is trace of rupture surface on original ground surface;
lower portion
, section in which hatching indicates
undisturbed ground, stippling shows extent of
displaced material, and broken line is original ground
surface. Numbers refer to dimensions defined in
Table 1.2 (IAEG Commission on Landslides,
1990).
Figure 1.6
Definitions of landslide features:
upper
portion
, plan of typical landslide in which dashed line
indicates trace of rupture surface on original ground
surface;
lower portion
, section in which hatching
indicates undisturbed ground and stippling shows
extent of displaced material. Numbers refer to
dimensions defined in Table 1.1 (IAEG Commission
on Landslides, 1990).
