Project MI-23-010 – Driefontein SCPTu Testing

Project Overview
This long-term ground investigation project focused on the geotechnical assessment of gold tailings storage facilities at Driefontein. Over the course of the project, Mukona delivered SCPTu, DMT, Electronic Shear Vane testing, and Vibrating Wire Piezometer (VWP) installation. The project demonstrated the value of combining multiple investigation methods to accurately assess complex tailings conditions.

Project Outcome
This project showcased Mukona’s expertise in large-scale tailings investigations. The excellent agreement between SCPTu, DMT, and Shear Vane results increased confidence in the interpretation of subsurface conditions, while the successful installation of 56 VWPs provided long-term monitoring capability for the tailings storage facility. The experience gained has further strengthened Mukona’s technical knowledge and investigation procedures.

Scope of Work

Completed SCPTu testing to approximately 60 m using the 200 kN Pagani CPT rig.
Successfully investigated soft gold tailings where the Pagani rig provided sufficient anchoring and reaction force.
Completed Electronic Shear Vane testing at all SCPTu locations to determine undrained shear strength.
Identified a significant weak layer near a sinkhole between 12 m and 16 m, where SCPTu recorded almost no sleeve friction or penetration resistance.
DMT testing independently confirmed the SCPTu findings, with the blade advancing under its own weight through the same weak zone, validating the quality of the investigation data.
Operational lessons from DMT testing improved understanding of pneumatic cable performance beyond 30 m depth and the importance of correctly isolating cable joints.
Completed more than 36 Electronic Shear Vane tests, with bent blades demonstrating the challenging and variable nature of the tailings deposits.
Installed 56 Vibrating Wire Piezometers (VWPs). Hard layers required pre-punching before installing push-in VWPs, ensuring successful installation without damaging the instruments.
Maintained high safety and quality standards throughout the project.

Project MI-23-010 – Driefontein SCPTu Testing

Scope of Work

Project Gallery

Let's build what's next