In consultation with the lead contractor and the RMS, Hitech Industrial Services was selected to perform hydro demolition on the existing bridge deck kerbs to cut approximately 18 cubic metres.
Bridges for the Bush
The bridge over Bemboka River at Moran’s Crossing was built in 1937 and is 7m wide and 92.2m long. It consists of seven spans, each measuring 7.45m, 13.90m, 16.5m, 16.5m, 16.5m, 13.90m and 7.45m.
As part of the Bridges for the Bush program the state government decided to widen this bridge on the downstream side which would ultimately minimise the impact on the local flora, fauna and particularly the local platypus habitat.
The RMS selected Hydro Demolition as the preferred method for concrete removal due to the reduction in noise, vibration, silica dust and importantly no micro cracking of the current structure or damage to the reobar.
Vulnerable Discovery
The discovery of a platypus in the river below the Bemboka bridge meant that new considerations needed to be undertaken with regards any water run-off into the river. This being one of the reasons for Hitech being selected.
Ability to remove concrete and surface membranes in a variety of situations
“Rivers and waterways are vital habitat for a range of marine life as well as marine vegetation.
Any type of construction work can have extreme consequences on this fragile environment and as company that values water it is our goal to ensure that the work, we do protects the environment be it on land or water to ensure that specifically any threatened species are sustained for generations to come.”
Mark Turner – Managing Director Hitech Industrial Services
Water run off
The water run off being caught by a steel plate (catchment tray) as per our design recommendation, which is guided to travel at its lowest point where the concrete and water are collected.
Catch and Release
Hitech Industrial Services method for this project was to use a robotic aqua cutter.
Encapsulation
The remote-controlled cutter breaks the concrete on the bridge and, is fully encapsulated.
The steel plate prevents the water jet cutting the timber deck .
Below the bridge catchment
A drainage pipe system from the bridge was installed and water flowed into a tank at the bottom of the bridge which was then pumped into the treatment plant of containers.
Note the wooden catch deck and pipe transferring run off water to the catchment tanks.
Onsite Filtration System
Captured water is treated, silt separated and clean
water pumped to a nearby paddock.
PH Levels were adjusted
Once the PH levels were reached/adjusted the clean water was used to provide water to an adjacent drought-stricken paddock.
The RMS approved this method which Hitech had used on other projects and this resulted in clean treated water.
No incidents occurred during the hydro demolition or water treatment process.
