Environmental Engineering Reference
In-Depth Information
TABLE 3.35
Shear Strength Parameters of Residual Soil, Weathered Rocks, and Related Materials
a
Strength Parameters
Rock Type
Weathering Degree
c, ¯ (tsf)
φ
,
φ
,
φ
r
Remarks
(see Table 6.15)
(deg)
Igneous Rocks
Granite
Decomposed
C
0
φ
27-31
500 tests, Cherry Hill
φ
avg
29
Dam
Quality index i
C
φ
In situ
direct shear tests.
15
1
41
Alto Rabagâo
10
2
45-46
7
3
49-52
5
5
57
3
6-13
62-63
Weathered, zone IIB
φ
r
26-33
Lab direct shear tests.
Partly weathered, zone IIB
φ
r
27-31
Alto Lindosa
Relatively sound, zone III
φ
r
29-32
Red earth, zone IB
φ
28
Decomposed, zone IC
φ
avg
35
Decomposed, fine-grained
c
0 if
φ
25-34
Decomposed, coarse-grained
saturated
φ
36-38
Decomposed, remolded
φ
22-40
Quartz diorite
Decomposed; sandy, silty
c
0.1
φ
30
Lab tests, UD samples
Diorite
Weathered
c
0.3
φ
22
CU triaxial tests
Rhyolite
Decomposed
φ
30
Metamorphic Rocks
Gneiss (micaceous)
Zone IB
c
0.6
φ
23
Direct shear tests
Decomposed
c
0.3
φ
37
Gneiss
Decomposed, zone IC
φ
18.5
CU triaxial tests
Decomposed (fault zone)
c
1.5
φ
27
Direct shear tests on
concrete-rock surfaces
Much decomposed
c
4.0
φ
29
Medium decomposed
c
6.5
φ
35
Unweathered
c
12.5
φ
60
Schist
Weathered (mica schist soil)
φ
24½
From analysis of slides
Partly weathered mica schists
c
0.7
φ
35
Perpendicular to
and phyllites (highly fractured)
schistosity
Weathered, intermediate
c
,
0.5
φ
,
φ
,
15
CU tests,
S
50%
zone IC
c
,
0.7
φ
18
CU tests,
S
100%
φ
,
21
Weathered
φ
26-30
Compacted rock fill,
field direct shear tests
Phyllite
Residual soil, zone IC
c
0
φ
24
Perpendicular to
schistosity
c
0
φ
18
Parallel to schistosity
(both from
analysts of slides)
Sedimentary Rocks
Keuper marl
Highly weathered
c
,
0.1
φ
25-32;
2% carbonates
φ
r
18-24
Intermediately weathered
c
,
0.1
φ
32-42
14% carbonates
φ
r
22-29
Unweathered
c
,
0.3
φ
40
20% carbonates (all
triaxial tests, D
and CU and
φ
r
23-32
cut planes)
