Mass Gravity Retaining Walls
2022
DURBAN - KWA-ZULU NATAL - South Africa
Oceans Mall - GEPF & Oceans Umhlanga Retail Company (Pty) Ltd
WK Construction
Sutherlands Engineers
D440 REHABILITATION
Before Construction
During Construction
Construction Completed
Problem
D440, a district road located in the Oslo Beach area on the South coast of KZN, is heavily trafficked. The frequent movement of industrial vehicles has led to various surface failures along the road’s entirety. Additionally, the region’s excessive rainfall led to erosion failure of the embankment supporting a specific section of the road, resulting in partial erosion and undercutting.
Compounding the challenges, the Port Shepstone locale lies within the Dwyker group Tillite formation, and the existing fill contained pockets of clay-like material. The road segment’s downhill slope, coupled with inadequate drainage, exacerbated the water ingress into the fill beneath the road.
Solution
The proposed solution included the construction of mass gravity walls to retain and prevent erosion around culvert pipes and control erosion in certain sections. Considering the topography of the area, Maccaferri proposed the use of 3x1x1m gabions and 3x1x0.3m Reno mattresses. As opposed to reinforced concrete structures, the gabions allowed the flexibility to accommodate differential settlement that may have occurred during and after installation, as well as allowing for the employment of local unskilled labourers for the construction.
All Maccaferri’s Gabions and Reno Mattresses are manufactured to SANS 23-3 (EN 10233-3) with double twisted hexagonal mesh. The steel wire is manufactured according to SANS 675 with Class A Zinc wire to SANS 1580. Where required, Polimac coating with a nominal thickness of 0,50 mm in compliance with EN 10245-1 protects the wire from aggressive environments.