The Redland City Council in Brisbane is experiencing an ongoing problem with canal revetment and retaining wall movement in Raby Bay and has initiated a trial to test the suitability of various treatment options.
The area has a history of ongoing canal revetment and retaining wall movement caused by ground instability due to the canal bank clay soils having lower than required strengths. Research has been ongoing since 1995 to understand the causes of canal bank failures and the council is keen to identify suitable remediation solutions. If the walls can’t be stabilised permanently, homes in the area could be compromised.
Redland City Council has engaged consulting engineering and design firm, Arup, to trial several different methods to help prevent the canal banks and associated retaining walls from moving, one option being Mainmark’s Teretek® engineered structural resin injection solution. Teretek is frequently used to re-level structures, however it is also a proven solution for improving ground bearing capacity and addressing ground cohesion issues that cause movement, such as voids and soil liquefaction. If successful, Teretek could offer considerable benefits to the residents of Raby Bay compared to alternative treatment options; being both cost effective and non-invasive.
The Raby Bay trials are now well underway with geotechnical assessments and extensive monitoring taking place to determine existing conditions and set the baseline for measurement. The treatments are being assessed according to five key factors:
Mainmark’s Teretek is an integral part of the two-year trial, which started in August 2016 and will continue until at least August 2018. If proven successful, Teretek will be an exciting solution for the Raby Bay site due to the resin technology’s ability to repeal water ingress while strengthening the ground bearing capacity of the soil. The Teretek process is similar to keyhole surgery, being non-invasive and time-efficient, with the treated areas safe to walk or drive on within hours of application.
While the early signs are looking positive, Mainmark is eagerly awaiting the outcome of the trials in anticipation that a viable long-term solution to the revetment issues for both Raby Bay and other projects facing similar structural stability problems can be delivered.
William Lindsay is the Group Technical and R&D Manager at Mainmark. He has over 25 years experience in working within the construction and civil engineering industries, having a wide breadth of experience, in the capacity of quantity surveyor, project manager/representative, business manager, general manager and group technical and research & development manager.