Environmental Engineering Reference
In-Depth Information
Figure 6.7 assesses the embankment for any
visible deformations of cross-section caused by
slope instability. There are a number of forms of
slope instability that can occur, and some are
more serious than others in terms of perfor-
mance. Cracking is a sign of slope instability but
to ensure that there is no duplication with the
'cracking and/or fissuring' PF the chart initially
in an embankment. Poor performance (grades 4
and 5) requires evidence of large burrowing ani-
mals or extensive burrowing. The very poor con-
dition also requires the presence of washed out fill
material to be evident. This indicates that seepage
or piping is actually occurring. If burrowing is not
extensive, the soil type of the fill material is used
to assign condition grades 2 and 3.
Assess structure for
obvious deformation
related to slope instability
Are sections of the slope out
of alignment or showing signs of
movement?
None
Minor
Severe
Are there any shallow
surface slips of the slope?
Ye s
Ye s
Are there cracks parallel to
crest with pronounced steps
and bulging at the toe of the
slope?
No
Is there any cracking
parallel to the crest evident
in the slope?
Is there any cracking
parallel to the crest evident
in the slope?
No
Ye s
No
Ye s
No
Condition = 1
Condition = 2
Condition = 3
Condition = 4
Condition = 5
Fig. 6.7
Flowchart to assess any deformation of embankment cross-section caused by slope instability.
