Peat and Drift GPR Assessment – Tazi Twé 138kV Transmission Line
Project Description

Transmission tower design requires detailed knowledge of the earth materials and stratigraphy at each proposed tower site.  During the routing phase of the proposed Tazi Twé 138kV interconnection transmission line in northern Saskatchewan, SaskPower planners hired JDMA to conduct ground penetrating radar surveys along the proposed transmission line right-of-way to determine the typical depth of peat and/or drift overlying the bedrock.  The surveys were carried out in wintertime to facilitate access to the peatlands and other low-lying areas along the right-of-way.

The JDMA field team used Sensors & Software Noggin 100MHz and 250MHz GPR systems mounted in a customized cargo sled, sturdy enough to be pulled behind snowmobiles and ATVs but portable enough to be carried in the back of a helicopter.  GPR profiles were calibrated from field observations and a series of measurements taken by a 2” hand-auger at some of the test sites.  The field team also collected apparent ground conductivity measurements using a Geonics EM-31 ground conductivity instrument and recorded observations on right-of-way access, local geological setting and potential construction issues at the survey locations.  The results of the surveys were compiled in a technical memo and provided valuable information to the SaskPower engineers designing the transmission structures.

Geotechnical engineering                   Ground penetrating radar

Project Details

JD Mollard and Associates

JD Mollard and Associates