Environmental Engineering Reference
In-Depth Information
Procedure
An electromagnetic vibrator located on the surface generates the Rayleigh waves. The wave-
lengths of these surface waves are determined by measuring the distance between two
points vibrating in phase with the source. The generated vibrations are measured with a
velocity or acceleration transducer and the wavelengths are measured by comparing the
phase relationship of vibrations at various radii from the source with the vibrations of the
source. Velocities are computed from the measured wavelength and the vibrating frequency.
3.6
Typical Values of Basic, Index, and Engineering Properties
3.6.1
Rock Masses
Relationships between the uniaxial compressive strength and the deformation modulus
for various rock types are given in Figure 3.92. Correlations with the rock mass rating
(RMR) system and the deformation modulus are given in
Section 5.2.7.
640
320
Steel
7. Granite
4. Limestone and dolomite
2. Diabase
160
7
2
1a. Granite,
80
8a. Schist, steep foliations
4
la
8a
3
Concrete
1b. Granite,
coarse,
altered
40
Chalk: blocky, medium hard
[Hobbs, (1975)]
lb
20
5
3. Basalt, andesite,
dacite, rhyolite
6
5
6
10
8b
5. Sandstone
6. Shale
8a. Schist, flat foliations
5
Chalk: weathered, fractured,
soft-filled joints
[Hobbs, (1975)]
2.5
1.3
Trials [Hobbs (1975)]
0.6
0.3
Keuper marl
0.15
Black shale [Hendron et al. (1970)]
0.07
Gray shale [Hendron et al. (1970)]
0.035
0.017
Very stiff clay
0.009
Firm to stiff clay
0.005
0.1 psi
Rock strength classification
Clay consistency
Fm
1.0 psi
0.003
St
V. St
Hard
Very low
Low Medium-high Very high
0.0015
0.5
1.8
7
30
125
500
2000
8000
0.9
3.5
15 60
Uniaxial compressive strength
U
c
(tsf)
250
1000
4000
FIGURE 3.92
Relationships between uniaxial compressive strength and deformation modulus for various rock types and
clays. (After Peck, R. B.,
Proceedings of ASCE,
New York, Vol. 2, 1976, pp. 1-21; and Deere, D. U.,
Rock Mechanics
in Engineering Practice,
Stagg and Zienkie-Wicz, Eds., Wiley, New York, 1968, Chap. 1.)
