Geotechnical Investigations

The project entailed geotechnical investigations for a Central Processing Facility (CPF) in Uganda and a pipeline to transport oil from the CPF 1100 kms to Tanga on the coast of Tanzania.

The project, which incorporates a geotechnical investigation and Lugeon testing for a potential dam site is located at two remote sites, one at Senqu B and the other at Oxbow.

The project required that we drill 6 holes (HQ3 size), with SPT’s, Shelbey’s and Shearvane testing, half a meter out into the sea from the Quay edge.

In June 2020 AECOM commissioned Geomech Africa (Pty) Ltd. to assist with the drilling of four geotechnical boreholes, a total of 70 meters, at the abutments of the existing Distillery Road Bridge crossing the Plankenberg River near Bosman’s Crossing in Stellenbosch, Western Cape. The existing bridge is the only access to Bosman’s Crossing. Due to its narrow dimensions, the bridge width needs to be widened to accommodate the increase of traffic.

“The Geomechanics drill team drilled 3 354 meters using the Reverse Circulation drill method.”

What is Reverse Circulation Drilling? Reverse Circulation drilling, or RC drilling, is a specific method of drilling which makes use of dual wall drill rods. These drill rods are a combination of an outer drill rod and an inner tube. With RC drilling, the rock is fragmented into chips by use of a piston that delivers rapid impacts to the stem of the hammer.