Geology Reference
In-Depth Information
Figure 4.34 Electric static cone penetrometer with piezometric ring. Forces on the cone tip are
measured independently from the force on the shaft section above. A combination of all three
characteristics.
Figure 4.35 Heavy
lorry being used to
conduct static cone
penetrometer tests.
as well as strength. A further re
nement (piezocone) allows water
pressures to be monitored as the cone is pushed in, which again can
help in interpreting the soil pro
le.
Large-scale direct shear tests are sometimes carried out in the
field
(
Figure 4.36),
in the hope that scale and disturbance effects might be
reduced. In reality, lack of control in the testing process, as well as
questions over representation of samples, however large, often out-
weighs any advantages. The derived data are generally less reliable
than those from a series of laboratory tests, which themselves would
need very careful interpretation before use at the mass scale, as
discussed in
Chapter 5.
