Civil Engineering May 2021 | Vol 29 No 4

16 May 2021 Civil Engineering walkway to allow for a transition between the two, while also functioning as a small barrier for pedestrians. IMPLEMENTATION With the decision made, it was time for public participation – just as the country was hit by the coronavirus and the nationwide lockdown put a hold on public gatherings. Meetings were moved to cyberspace, and the feedback from the sub-council and members of the public was generally positive. Due to the urgency of the work, the supply chain process was fast-tracked as far as possible. Within three months of submitting the tender documents to Supply Chain Management, the tender was ready to advertise. This was largely thanks to the efforts of the City’s bid specification committee. Although construction during winter is less than ideal, the rapidly deteriorating state of the gabion wall saw work on the revetment scheduled to commence in April 2020, as soon as funds were made available and the tender was awarded. Following the prescribed open and competitive process, the contract was awarded to Southern Oceaneering, the same contractor who implemented the country’s first geocontainer structure in Langebaan 20 years ago. The geocontainers were manufactured in Cape Town and filled with beach sand off-site at Melkbosstrand. Ideally, the con- tainers should be filled at the construction site, but due to the eroding beach in the vicinity of Big Bay, the City could not run the risk of using beach sand from the site itself. Once filled, the containers were transported down the road from Melkbosstrand and stockpiled on site. Construction of the revetment was sequenced in 10 m sections in order to expose the least possible “open face” to the sea, thereby preventing further erosion Although construction during winter is less than ideal, the rapidly deteriorating state of the gabion wall saw work on the revetment scheduled to commence in April 2020 It took approximately 1 100 geocontainers to complete the structure along the two sections Approximately 1 100 geocontainers were used in the structure along the two sections (Credit: Bruce Sutherland, CCT)