Your Dam Your Responsibility (PDF~1.2MB)

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A
Appendix A
Adequate coverage can be achieved using parallel or zigzag paths (Figure A-3).
Figure A-3 – Parallel Coverage Path
On the downstream slope a zigzag path is recommended to ensure that any defects are
detected.
Stop and Look
At several points on the slope, you should stop and look around through 360 degrees to
check alignments and to be sure that some important feature of the slope has not been
overlooked.
(e) Particular Techniques
The following is a list of methods that can be used to monitor changes, which will occur
over a period of time.
Sighting
A sighting technique, similar to that used when selecting straight pieces of timber, can
be used in identifying misalignment as well as high or low areas along a surface. The
technique is illustrated in Figure A-4.
Figure A-4 – Sighting Technique
The same method can be used to sight along the crest of a dam (see Figure A-5). Centre
the eyes along the line being viewed. Sighting along the line, move from side to side a
little to view the line from several angles.
Looking through a pair of binoculars will help to make any variations more obvious,
Probing
The probe is pressed into the earthen batter slopes, on the crest or at places being
inspected. Conditions below the surface, such as depth and softness of a saturated area
can then be observed. Also, by observing the moisture brought up on the probe’s surface