Mount Whaleback Tailings Sampling

As part of the project, we recently completed our second round of sampling works, this time at BHP’s Mount Whaleback mine tailings storage facility. In this sampling work, we attempted a new sampling method to allow us to take a large quantity of material from depths relevant to in situ testing results, as follows:

1. Three piezocone penetration tests (CPTu) were carried out in a 4 x 4m area

2. The locations of each CPTu were surveyed

3. A battered excavation to about 4m depth was created, to enable safe access

4. The locations of the CPTu probes were identified, and new benchmark survey levels established

5. A large quantity of bulk and block samples were taken from known depths adjacent to the CPTu probe locations

This sampling process enabled us to obtain high quality block samples, and a sufficient quantity of material to enable carrying out calibration chamber testing at UWA and UNSW, and beam centrifuge testing at UWA.

Thanks very much to BHP’s site and corporate personnel for their support in the sampling efforts, and to Golder and Probedrill Geotechnical Survey for assistance with site logistics and CPTu works.

Image 1: CPTu rig moving into position for testing

Image 2: Excavation works

Image 3: Completed battered excavation

Image 4: Jaime Castro of UWA establishing the elevation of block samples, referenced to an adjacent CPTu test location

Image 5: Filling Bulker Bags to provide material for calibration chamber and beam centrifuge testing