CPT Testing for tailings facility design | Malawi

Geomechanics was tasked with conducting Cone Penetration Testing (CPTu) at a mine, located about 60 kilometres north of Lilongwe, Malawi. The work formed part of the geotechnical investigation for the design of a new tailings facility. In total, our team completed over 500 metres of CPTu testing and 4,100 minutes of dissipation tests across 41 test positions.

The project kicked off under tight deadlines, with the team mobilising quickly to meet the client’s schedule. The first few test locations presented immediate challenges — the area was heavily overgrown, making access nearly impossible at first. Our crew had to cut pathways through the thick bush just to reach the initial testing points. Once the routes were cleared, the rest of the site became much easier to navigate, allowing us to pick up pace.

We aimed for a target depth of 20 metres at each position, but the ground conditions posed challenges. In some areas, we hit refusal as shallow as 2 metres due to very hard layers in the subsurface. Rather than lose time, we coordinated closely with the auger team on site, drilling through the obstructions so that CPT testing could continue as planned. This collaboration was key to maintaining momentum and delivering results within the required timeframe.

All testing was carried out using Geomechanics’ custom-built Colossal CPT rig — a 20-ton, track-mounted powerhouse designed specifically for difficult terrain. Its strength and stability proved invaluable in navigating the challenging site conditions and achieving reliable results.

Despite the obstacles, the project was completed efficiently and safely. The experience showcased our team’s adaptability, problem-solving ability, and commitment to getting the job done right. In the end, Geomechanics delivered a comprehensive dataset that provided critical insights for the ongoing design and development of the tailings facility — a result we’re proud to have achieved under demanding conditions.