UNDERWATER GROUT BAGS
The Australian Boom and Baffle Co
specialises in the design and fabrication of underwater
grout and gavel bags.
Our in house testing capacity and
high strength geo-textile fabrication equipment enables
us to progressively test to agreed design criteria
throughout the manufacturing process. We regularly use
geo-grid internal supports to hold the shape of the
structure whilst allowing grout to flow freely through
the bags.
Our specialist products include:
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Mass Anchoring Underwater Pipe
Saddles |
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We are able to
configure underwater pipe saddles specially to
clients specifications to provide both support and
mass anchoring.
Once deployed
pipes can be secured to the saddles using heavy
duty stainless steel straps.
In the example
pictured opposite saddles were constructed
for 2 of 1800mm cement coated pipes.
As the
pictured grout bags are to be filled underwater, a
pre-deployment trial was undertaken on land to
verify bag formation and strength.
In this
example they were filled with 25 mpa block mix
with 10mm aggregate through 80mm fill pipe. Each
bag holds approximately 7.5 cubic metres.
During the dry
trial divers were walked through the installation
procedure and an appropriate safe work method
statement was prepared for their installation. |
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| Bags
constructed to enable divers to haul under pipes
which are held in a cradle and attach to pipes in
1 knot of current |
To
ensure bag forms to required footprint plastic
conduit is used by the divers to peg the bags to
the soft bottom |
Progressive
filling is undertaken to ensure even distribution
of grout |
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| Fill
relief ports are located in each major segment of
bag to ensure that each section is adequately
filled |
In
this shore trial two saddles were installed to
ascertain potential slump after removal of
supporting cradle |
As
filling is undertaken the supporting straps are
cutoff to allow the bags to expand with out
restriction and wrap tightly into pipes |
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Examples
of Underwater Grout Filled Structures |
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Cylindrical
impermeable tube manufactured from WWT 80kN coated
fabric. Coated fabrics are used in highly
sensitive areas where bleeding from a standard bag
needs to be limited. NB pressure relief/water/air
bleed ports on top tube.
Progressive
internal reinforcement ensures tube holds
structure when inflated |
Flat
impermeable mattress manufactured from WWT 80kN
coated material. Internal structure ensures that
mattress can be inflated to designed height whilst
providing a consistent coating of grout to prevent
ice cube break-up. Use scour protection at
wharf segment toes, spillways etc |
Permeable
Mattress for scour protection manufactured height
100 to 250mm |
Permeable
pipe support mattress. Nominal height 250 to
350mm. Internal structure is varied according to
pipe diameter to allow mattress to act as a saddle
to limit pipe roll whilst maintaining a continuous
coverage of grout. Providing better support than
multiple bagging |
