Recent News

Reinstating Abel Erasmus

By Hannes Taljaard, Geotechnical Engineer and Thomas O’Brien, Director: ARQ Geotech (Pty) Ltd.

South-eastern Limpopo provides spectacular landscapes, ranging from mountains and deep valleys to the well-known bushveld. The Abel Erasmus Mountain Pass, on the R36 between Ohrigstad and Hoedspruit, boasts just such picturesque settings as it winds through mountainous terrain before passing through the 136 m long JG Strijdom tunnel and dropping off down to the banks of the Olifants River. Thoroughfare was, however, threatened by a large slip failure which occurred in the embankment of the southbound lane circa 2013. An assessment of the site revealed that a 15 m high portion of the embankment had slipped, thereby undermining ~1.5 m of the right-hand side (RHS) of the roadway and compromising both capacity and safety.

A geotechnical investigation, which was unfortunately limited by necessity, was undertaken by ARQ; it provided some insight into the subsurface makeup of the embankment and in-situ hillside. Representative strength and stiffness properties were obtained for the fill material through laboratory work, including triaxial testing.