GEOmasta helps stabilise slope alongside Brisbane’s Kedron Brook
Kedron Brook Slope Remediation
Bellwether Constructions, February 2019
Bellwether Contractors were engaged to complete a creek bank stabilisation and remediation project adjacent to a local shopping centre in Brisbane. An embankment next to the existing creek had eroded and destabilised the carpark pavement, and specialist GEOmasta products including EroWeb, mastaTEX Nonwoven and Strip Drain were required to help improve stability and drainage to the area.
The Brookside Shopping Centre is located adjacent to the existing watercourse of Kedron Brook in the Brisbane suburb of Mitchelton. Brisbane City Council, in conjunction with the shopping centre management, required a contractor who could stabilise and remediate the semi eroded creek bank that ran alongside the shopping centre carpark boundary.
Principal contractors Bellwether sought a supplier who could supply reliable, effective geosynthetic products. GEOmasta geotextile, geocell and strip drain products were specified due to their high quality and proven performance in the field.
GEOmasta mastaTEX Nonwoven, GEOmasta EroWeb and DRAINmasta Strip Drains were utilized to improve the embankment.
GEOmasta supplied Bellwether with mastaTEX Nonwoven GF54 and mastaTEX Nonwoven Class C GF34 as a separation and stabilisation layer. mastaTEX Nonwoven is a continuous filament PET geotextile that is used extensively in road and rail works as well as in landscaping for slope stabilisation.
Then, DRAINmasta Strip Drain was laid at intervals to help efficiently filter and transport water runoff into the creek. Specifically designed for subsoil drainage, Bellwether chose the 200mm strip drain to effectively filter runoff, thereby helping to maintain the health of the waterway.
Finally, EroWeb EC1535 was installed to create a suitable base for subsequent landscaping and revegetation. EroWeb is a lightweight and flexible 3D geocell constructed from perforated HDPE. It assists with slope protection and erosion control and can be filled with a range of material including aggregate, concrete, sand or in this case, soil.
A landscape contractor was subsequently engaged to revegetate the riparian corridor with grasses, trees and shrubs.
THE PROJECT IN DETAIL
In 2018, significant erosion and embankment failure were identified alongside Brookside Shopping Centre carpark. An engineering assessment recommended remedial and stabilisation measures should be undertaken at 10 locations along the bank of Kedron Brook.
Engineering drawings and a flood impact assessment using 2D hydraulic modelling confirmed that remediation works would not adversely impact flood behaviour in the creek. Vegetated rock protection was recommended as a preferred treatment, and Brisbane City Council in conjunction with shopping centre managers Retail First engaged contractors to carry out the works.
Bellwether Contractors secured this project along with a series of subcontractors, and the necessary works were undertaken to restore the stability of the Brookside Shopping Centre carpark and prevent further erosion.
- Approximate quantities supplied:
- 6,000sqm MastaTEX Nonwoven GF54
- 15,000sqm MastaTEX Nonwoven Class C GF34
- 1,500sqm EC1535 GEOmasta Eroweb
- 1,200sqm 30-SD200 Drainmasta Strip Drains 200mm
- Time Period: Installed February 2019
- Customer: Bellwether Contractors Pty Ltd
GEOmasta mastaTEX Nonwoven
DRAINmasta Strip Drain
Kedron Brook Slope Remediation
Mitchelton, QLD, Australia