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A21 Dyke Construction Diavik Diamond Mine

  • SECTOR: Mining- Geotechnical
  • LOCATION: Diavik Diamond Mine, NWT
  • DATE: 2017 to 2020
  • EQUIPMENT: Fraste MDXL & MDXL Max

Geotech was awarded a program to participate in the Diavik A21 Dyke construction drill program starting in 2017 with drilling and installations of the thermistors, inclinometers, vibrating wire piezometers, survey markers, and pumping wells. Geotech was also requested to complete an additional scope including extensometers, PQ coring, and geo-bore drilling. A range of borehole diameters from 6” to 10” was completed to targeted overburden depths with surface casing and rotary air blast (RAB) open hole completion from 4” to 8 ¼” to final hole depths.

Based on the work completed and successes from the 2017 instrumentation drilling, Geotech was awarded a large diameter dewatering program in 2018, where 10” casing and 8” RAB holes were drilled up to 175 meters with de-watering pumps installed.

Geotech was further awarded two more programs in 2018 and 2019 to complete more dewatering drilling in over 22 holes to depths up to 275 meters.

CHALLENGES

  • Remote location required mobilization on the ice-roads. No land access for 10 months of the year.
  • Winter conditions include temperatures as low as -40° Celsius. High arctic winds and flat landscapes also presented challenges with whiteout conditions.
  • Large diameter deep hole drilling with large volumes of water.
  • Extensive pilot and cased drilling to get through artesian and challenging rock conditions to set the pumps.
  • Up to 90 meters of casing.


ACHIEVEMENTS

  • Total depths of 275 meters holes with 8.25” diameter
  • Installations of 6” pumps to 240 meters
  • Implementation of a specialized cyclone system to suppress water volumes and enable chip sampling
  • Spyder magnets, piezometers, slope inclinometers, and survey markers successfully completed in order to finalize the dyke.