Eastern Cape, March 2008
Engineer: Roshcon Civil Infastructure
Geotechnical Engineer: Control Civil Services cc
Owner: Eskom Distribution
Manufacturer: Coastal Technicrete – Port Elizabeth
Product: Armorlex 140 – grey – 340 X 400 X95
Mbashe Access Road is located approximately 50km North East of IDutywa in the old Transkei area, near Collywobbles.The access road is extensively used by ESKOM maintenance crews from Mthatha passing through to the Mbashe Hydro Power station situated on the Mbashe River. The road is also in daily use by the local community.
Excessive damage to the existing road was caused by slope instability. The embankments slipped and blocked the earth drains. The cross fall of the access road was away from the embankment, the combined effect of these contributing factors lead to excessive erosion of the access road surface.
Remedial actions that were imposed are as follows:
- Re- grade the exiting access road to 2% cross fall into the embankment.
- Trimming of collapsed embankments and use material for road, Cost saving on importation from commercial source.
- Construction of Gabion retaining wall in Identified critical areas where high velocity water flow occurs.
- Construction of Technicrete Armorflex side drains
- Construction of Technicrete Armorflex road ways in steep grade areas exceeding 15.
- Cleaning of existing pipe crossings.
- Filling up of heavily eroded side drains, compact and re- cut new drains.