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| Other Australian examples |
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Pages in this section include:
| Murray
Irrigation Limited - Mulwala Canal |
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(McCann and Kelly, 1998; Aseervatham and Thompson, 1998)
A 1.4km section of the southern embankment of the Mulwala canal
managed by Murray Irrigation Limited was remediated using high-energy
impact compaction of in-situ material.
Seepage was evident along the toe of the embankment and outside
wall. A geotechnical inspection found that the banks were constructed
with a combination of silty clays and silty sand clays of medium
plasticity and clayey gravelly sands of low-to-medium plasticity.
A 4m-wide strip was graded on the crest of the bank to clear the
topsoil and to provide a reasonable profile for compaction.
Compaction was undertaken using a three-sided high-energy impact
compactor on the crest of the bank. Compaction was undertaken on
a daily basis for 15 days with a few hours of compaction each day.
High initial settlements were achieved over the first few days.
Compaction was also done on the outside of the channel at the foot
of the embankment in order to reduce seepage through the floor
of the channel under the embankment.
The average and maximum settlement recorded on the embankment over
the compacted area was 330mm and 410mm respectively and effective
reduction in the embankment height of 15.5% and 18.5%.
Visual observations of the canal showed no evidence of water logging
at the foot of the embankment. The watertable on the outside of
the bank had dropped approximately 250mm indicating a reduction
in the level of seepage.
| Goulburn
Murray Water |
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(Dunstone, 1998)
To remediate seepage from a 2.2km reach of the CG Channel No. 4,
Goulburn-Murray Water selected a compacted clay liner 300mm thick
in conjunction with a geotextile underlay and a 150mm protective
layer of crushed rock. The cost of stripping the old channel, laying
the geotextile, placing and compacting the clay liner and the rock
protection was estimated at $187/m (approximately $14/m2). The
installation was expected to achieve a seepage rate of approximately
2L/m2/day.
| Related
pages |
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Earthen lining
techniques
Compacted earthen liners
Clay lining example:
Channel 12
Clay lining example:
Waranga Western Channel
Channel bank lining
Loose earthen linings
Bentonite treatments
Modified soil earthen linings
Soil sealants |
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