Geoscience Reference
In-Depth Information
Table 4.5
In situ test methods and general application (Bowles, 1996).
Test
Area of ground interest
Acoustic probe
C
B
B
C
C
C
C
C
Borehole permeability
C
A
B
A
Cone
Dynamic
C
A
B
C
C
C
C
Electrical friction
B
A
B
C
B
C
B
C
B
Electrical piezocone
A
A
B
B
B
A
A
B
B
A
B
B
A
Mechanical
B
A
B
C
B
C
B
C
B
Seismic down hole
C
C
C
A
B
B
Dilatometer (DMT)
B
A
B
C
B
B
B
C
C
B
Hydraulic fracture
B
B
C
C
Nuclear density tests
A
B
C
Plate load tests
C
C
B
B
C
B
A
B
C
C
B
B
Pressure meter menard
B
B
C
B
B
C
B
B
C
C
Self-boring pressure
B
B
AAAAAAAABAA
Screw plate
C
C
B
C
B
B
A
B
C
C
B
B
Seismic down-hole
C
C
C
A
B
B
Seismic refraction
C
C
B
B
Shear vane
B
C
A
B
Standard penetration test (SPT)
B
B
B
C
C
C
A
Vertical consolidation with horizontal drainage:
C
v
Vertical consolidation with vertical drainage.
C
h
=
=
Code:
A
=
most applicable.
B
may be used.
=
C
least applicable.
=
•
The first 150mm is the seating drive, which allows for possible material fall in at
the base of the hole and/or loosening of base material. Comparison between each
150mm increment should be made to assess any inconsistencies. For example N
values 1, 7, 23 suggests:
- An interface (examine sample recovery if possible); or
-
Loose material falling into the base of the borehole, and the initial seating and
first increment drive represents blow counts in a non in situ material.
•
The SPT is the most common in situ test. However it is not repeatable, ie
2 competent drillers testing next to each other would not produce the same
N -Value.
•
Correction factors need to be applied for overburden in granular soils and type of
hammers.
Search WWH ::
Custom Search