Backed up by Adelaide based compaction specialists, Broons Hire, Clyde has
employed the proven technology of Impact Compaction to overcome their hurdle
utilising a pair of Broons' BH-1300 "Square" Impact Rollers.
Stuart Bowes, Manager for Market Development with Broons Hire, takes up the
story.
"Several areas on the floor of the storage were marked out for trials
to determine the optimum number of passes before the bulk of the project got
under way. Selected areas both in the borrow pit and on natural ground were
treated. Testing resolved that while a minimum of 10 passes would achieve a
satisfactory result, 14 passes provided additional security at minimal extra
cost."
"An unseasonally wet winter delayed progress across the floor of the
massive storage but in the end the project came in on time and well under the
original budget estimates with an alternative machine".
Piezometers set around the storage will monitor the ongoing success of the
Impact Compaction.
"The job at Beemery is certainly the largest single storage we have
Impact Rolled in a lengthy history spanning over 10 years with the Cotton
Growers throughout Australia. The Bourke area has proven particularly suited to
our Impact Roller," said Mr Bowes. "2000 Cotton Achiever of the Year,
Steve Buster Darling Farms has used our machine since 1997 while both the Bourke
and Brewarrina Shires have proof rolled over 100kms of black soil road
formations using our Roller". cont...2 - 2 -
An impressive feature Broons' "Square" Impact Roller is the high
travel speed combined with the depth of influence resulting in significant
productivity, far in excess of that achieved with alternative compactors.
Operated at around 10kph, the 13.8 tonne "Square" Impact Roller covers
2,300m2 per hour with 10 passes of the machine.
"Our water resources are a valuable commodity in the driest continent
on earth and we are proud that a machine developed by an Australian company is
playing a crucial role in the battle against water loss and ultimately
devastating salinity. Success with progressive Australian Cotton Growers
including former Cotton Grower of the Year, Peter Glennie Norwood, has led to
wider acceptance of Impact Rolling throughout the irrigation industry in general
including Rice Growers in the NSW Riverina."
"In addition, Murrumbidgee Irrigation and Marthaguy Irrigation have
successfully treated previously leaking channels", remarked Mr. Bowes.
Broons Hire offers a number of units available for long or short term hire
in their nationwide fleet.
UNIVERSITY STUDY CONFIRMS BROONS' BH-1300 "SQUARE"
IMPACT ROLLER REDUCES WATER LOSS IN COTTON REGIONS
A recent study conducted by Mr. Nik Auzins from the University of New
England, Armidale N.S.W. has concluded that Impact Compaction can achieve
significant benefits in assisting to reduce water loss in high usage irrigation
farming such as cotton and rice.
Trials, conducted with the assistance of Mr. Peter Davidson, were held on
the 15,000ha Tandou Farm in far western New South Wales with technical support
from Impact Roller manufacturer, Broons Hire,
"The Impact Roller offers potential in minimising water losses in
agriculture from seepage, through compaction", claims the detailed report.
Findings of the study, presented by Mr. Auzins at the 8th ANZ Geomechanics
Conference in Hobart, went on to say, "Investigations at a field site
showed an increase in density and reduced permeability in highly plastic clay
soil, commonly found in cotton growing areas, after the application of an Impact
Roller".
Insitu permeability tests were undertaken at several levels down to nearly
one metre on two embankments that were known to be leaking beforehand. After 15
passes of the Broons BH-1300 "Square" Impact RollerTM, results
indicate hydraulic conductivity was reduced to an unmeasurably low value below
250mm from the surface.
A major benefit of the BH-1300 "Square" Impact RollerTM is it's
significant depth of influence, often over 1.5m, in comparison to conventional
vibrating rollers that struggle to handle 250mm layers in heavy clay.
The depth of influence and high productivity, in excess of 1500m2/hr, are
key factors when considering the application of the Impact Roller to treat
leaking channel banks and water storage floors. Costly alternatives such as clay
or synthetic liners, or chemical additives are generally not viable due to the
large areas to be covered.
Compaction has often been a secondary consideration during construction of
the banks and storages. Growers frequently rely on the movement of earthmoving
plant across the fill to compact the material in an attempt to minimise the
expenditure of these massive infrastructure projects.
"Ongoing failures in channel banks and storage walls has highlighted
the need for closer attention to compaction during construction or at the very
worst, preventative action on existing structures before the problem arises.
Based on the findings of this report, our "Square" Impact RollerTM
should be strongly considered as a cost effective solution to minimising leakage
or failure." said Broons' Manager Market Development, Stuart Bowes.
From their success in the Australian cotton regions over the last eight
years, Broons have diversified into other agricultural applications including
the extensive rice growing area in the NSW Riverina where excessive permeability
of the soil is leading to increased salinity, forcing growers to abandon fields
entirely.
"The fundamental principal remains the same in both the rice and cotton
industries - both want to stop water loss! The difference being, Rice Growers
still want the ground soft enough so as not to affect their yield",
commented Mr. Bowes.
Generally between three and six passes have shown to be adequate to seal
rice fields, relying more on the kneading action of the Impact Roller reworking
the poor soil structure to reduce permeability than a significant increase in
density by compaction through an increased number of passes.
"Proving the value of Impact Rolling has taken many years while we wait
for the results to flow", said Mr. Bowes. "Now, with our past track
record, we are finding it's becoming a more accepted practice as conventional
solutions are often expensive or only short term stop gap measures".
Authorities, such as Marthaguy Irrigation near Warren, Murrumbidgee
Irrigation at Griffith and Leeton, and Narromine Irrigation claim successful
results having used the Broons BH-1300 "Square" Impact RollerTM.
GROWERS REAP REWARDS WITH BROONS SQUARE IMPACT ROLLER
Never one to rest on its laurels, Australian firm, Broons Hire, has continued to
pursue uses for its revolutionary BH-1300 "Square" Impact Roller, outside the
general earthmoving and civil engineering sphere. Cotton Growers throughout New South
Wales and Queensland have been quick to try the concept, while their counterparts in the
Rice Industry have recently "cottoned" on to the idea as well.
Water is a valuable resource in the driest Continent on earth, and irrigation farmers
in Australia know this only too well. Rainfall can be infrequent, forcing Growers to rely
heavily on water allocations from rivers and bores drilled into subterranean sources.
Timing is crucial to their survival and water is more often available in large quantities
when they need it least.
To overcome this cyclical hurdle, massive above ground water storages (or reservoirs
as they can be called) are constructed to hold water for later use. Earthworks involved in
the construction of the storages and associated channels, frequently involve moving
hundreds of thousands of cubic metres of clay, rivalling many large scale general civil
engineering projects!
When constructing these huge storages, upwards of 15ha (37acres) on the floor,
specific attention to compaction has often been considered a low priority, relying more on
the compactive effort of scrapers and dozers, and the swelling and sealing ability of the
heavy clay when wet to keep things together. As time passed, many Growers found their hard
earned dollars vanishing along with their water, through leaking floors, channel banks, or
at worst, a break out of the dam wall, generally destroying a valuable crop along the way.
Enter Broons Hire and their unique BH-1300 "Square" Impact Roller. Already a
proven performer in the civil contracting industry, the challenge was thrown out to the
Adelaide based company to try their hand at solving the problems of leaking water storages
in the Cotton regions of Australia.
Initial trials in the early 1990's revealed challenges for the BH-1300 Impact Roller,
not generally encountered in the past on regular civil engineering projects. Particularly
on the floor of the storage, the high PI clay can be heavy going when damp, often
resulting in the 7.8 tonne "Square" impact module kneading the ground rather
than striking it as was previously considered necessary. Results have since proven this to
be advantageous in some conditions, breaking up the piping effect found in many soils,
left by decaying roots and earthworms, and caused by the random removal of trees and other
vegetation during construction.
On dam walls and channel banks, the BH-1300 "Square" Impact Roller really is
in a class all on its own. It's depth of influence can be upwards of 1.5 metres in some
soils, far out of reach for conventional vibrating compaction equipment, and with a travel
speed of around 12kph, many thousands of square metres per day can be covered resulting in
excellent productivity and a cost effective method of reducing water loss by sealing the
ground. The Broons BH-1300 "Square" Impact Roller can be used during
construction or to improve poorly compacted materials in-situ on existing storages and
channels.
Continuing success in the Cotton Industry, has resulted in an approach to Broons to
try their hand at minimising water loss in the rice growing regions throughout southern
New South Wales, caused by the high permeability soils in which some crops are grown.
Regional Water Authorities are rapidly preventing Growers from sowing fields that have
excessive water usage during irrigation, resulting in land being returned to uses that
provide less profitable returns for the Grower. Already, early trials indicate, Impact
Compaction to be a viable method of reducing water loss on these fields.
Extensive Australian and International use of the Broons BH-1300 "Square"
Impact Roller over the last 12 years has allowed Broons to build up a thorough library of
field data across a wide variety of projects around the world. Machines are available for
hire in every state and experienced personnel are on call across the country and overseas
to assess Contractors and Growers needs, providing quality advice.
