Soil Exploration - Soil Properties: Testing, Measurement, and Evaluation - page 8

Figure 2-2
Test Pit
Figure 2-3
Backhoe
(Courtesy of Caterpillar,
Inc.).
obtained by carving an undisturbed sample from the pit's sides or bot-
tom or by pushing a thin-walled steel tube into the pit's sides or bottom
and extracting a sample by pulling the tube out. (Undisturbed samples
should be preserved with wax to prevent moisture loss while the sam-
ples are transported to the laboratory.)
Test pits are excavated either manually or by power equipment,
such as a backhoe or bulldozer (see Figure 2-3). For deeper pits, the ex-
cavation may need to be shored to protect persons entering the pits.
Soil inspection using test pits has several advantages. They are rel-
atively rapid and inexpensive, and they provide a clear picture of the
variation in soil properties with increasing depth. They also permit easy