Geotechnical Drilling - Rocks Road

Rocks Road, Nelson

Opus International.

Drilling Project Brief
Drilling three HQ Core holes to maximum depth 35m, to determine structure of upper slope of Rocks Road. The project was carried using a man portable rig (Hydro 200), two holes drilled in private property adjacent to a home, the third on Road Reserve overlooking SH6, Rocks Road.
Holes had instrumentation installed at completion, either inclinometers or piezometers.

Drilling Project Challenges
Very difficult environment for drilling.
Steep terrain with very limited access.
Drill power onsite limited - access only allowed use of small drilling rig.


The project progressed exceedingly well, especially considering the geographical challenges. The work was completed to everyone's satisfaction and within the allocated budget, unfortunately there were some unexpected time delays so it took slightly more time than originally planned.



Drill Projects

Geotechnical Drilling - Cardrona Ski Field

Project involved drilling a single core hole in PQ TT to 25 metres and carrying out SPT testing at 75m intervals. Access over busy ski lanes and soft snow covered ground was a challenge and a snow groomer was required to tow our lightweight Hanjin 8D rig to site.

Geotechnical Drilling - Karamea Road

Project involved drilling 20 boreholes using two different methods, HQ TT Core in cohesive materials, and concentric casing advancement in loose colluvium. All holes were drilled in or above landslide debris, over a 30km stretch of road between Mohikinui and Karamea.

Geotechnical Drilling - Kawarau Gorge

Two geotechnical bores of over 50 metres were required on this project in Central Otago. The location was particularly tricky, with one site being 80 metres above the road on a steep track, while the other was adjacent to the very busy Kawarau Gorge Road.

Rock Anchor Installation - Haywards Power Station

Assistance was requested to complete the drilling and installation of 54 multistrand anchors. This was to support the seismic upgrade of Transpower’s Haywards PowerStation in the Hutt Valley.

Geotechnical Drilling - Deans Head

Two geotechnical holes required, PQ Cored to 35-40m depth through landslide to assist Geotechnical Engineers to determine long term stability. Due to the nature of the location we chose to utilise our fly rig (QM750) and needed a helicopter to gain access.

Installation Drilling - Takaka Hill

Required to drill and install temporary casing through a variety of formations to allow the installation of 80mm conduit to carry broad band cables for Golden Bay.

Installation Drilling - Rocks Road

Drilling and installation of anchors for a retaining wall. The project required the drilling, installation, grouting, testing, lock off and post grouting of 30 anchors of varing size, to anchor a replacement wall.

Geotechnical Drilling - Ferrymead

PQ and HQ core recovery required for a Mass Movement study on a difficult access site in the Bray/Quarry Road area in Ferrymead.

Installation Drilling - Maitai Pipeline

Drilling and casing through compacted Fill into bedrock using a 300mm Tubex casing advancement system, installation of a bed of cathodic anodes to assist with the long term protection of the new pipeline being laid to supply water to Nelson city.

Geotechnical Drilling - Picton Foreshore

Carry out investigative geotechnical drilling for proposed foreshore development (development is now completed).

Investigation Drilling - Mohikinui River

Carry out investigative drilling to determine strata below the actual river bed.

Exploration Drilling - West Coast

Immediate drilling required in remote and extremely steep country all within typical dense West Coast bush.

Investigation Drilling - Reefton

Drill series of deep HQ core holes for slope stability study.

Investigation Drilling - Lee Valley Dam

Multiple investigatory bore holes for initial design feasibility on potential irrigation dam.