Environmental Engineering Reference
In-Depth Information
Figure 5.8.
Log of test pit.
- Local laws on support requirements of excavations must be followed. Collapse of pit
walls occurs commonly, particularly in wet ground. The effective use of steel or timber
support (
Figure 5.9
)
can enable safe access to pits for logging and sampling;
-Groundwater inflows may cause excessive collapse and limit effective excavation, even
with supports;
-Test pits disturb the local environment, but if carefully backfilled and the site revege-
tated their long term impact is minor.
5.6.2
Trenches
A logical extension of the use of test pits is the excavation of trenches, using either a tracked
excavator or bulldozer and ripper. Such trenches provide virtually continuous exposures
