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GEOTECHNICAL STUDY

GEOTECHNICAL RESEARCH

 

Phase 1: Desktop Study, September 15, 2021 – December 31, 2021. Geotechnical Firm: Englobe Corp. 

Phase 2: Field Work, April 1, 2022-December 31st, 2022 (pending)

 

The piece of land selected for our building is one of few remaining in Cambridge Bay that meets our organization’s requirements of a central location for easy access by Elders and Youth, coastal proximity for access to boats, skidoo and sled paths, and sufficient land area to design and implement outdoor cultural activity areas. This large piece of land has not been developed to date due to it being zoned as Commissioner’s Land. In support of our proposed cultural Centre’s construction, the Municipality has agreed to rezone 3,875 square meters of this land for our use. Despite its many positive attributes, the land is also positioned to be highly impacted by climate change. 

 

Our first Climate Risk Assessment highlighted several potential infrastructure and site vulnerabilities to a changing climate. The site is adjacent to a seasonal drainage corridor, which is prone to spring flooding. The land is sloped, and seasonal washouts might occur (exacerbated by rapid snow melts and increased precipitation). Radar interferometry maps show the area to be highly impacted by terrain instability, including permafrost degradation. These are all factors which are predicted to increase with the onset of climate change. With the Canadian Arctic being highly prone to climate risk, we see our building project as an opportunity to devise innovative new solutions to community adaptation around these issues.  

To address those, we are initiating a series of geotechnical studies of the site to assess the extent of these concerns and adjust the foundation design of our new building to adapt to them. A thorough geotechnical study of the land will allow us to 1) assess the suitability of the site, 2) identify where additional studies are warranted, 3) design building foundations appropriate to current and future site conditions, and 4) implement adequate mitigation measures (such as thermosyphons, landscaping, operation and maintenance practices) if necessary. 

 

A better understanding the physical properties of the permafrost and ground layers beneath our building will help us create a more adaptive design to handle these measures. Our path forward is as follows:

 

  • We retained the services of Englobe Corp. to conduct a desktop exercise this fall, looking at current and future permafrost conditions, historical water drainage level and slope assessment. This desktop exercise includes a strong climate lens (with an understanding of the high uncertainties associated with such work), recommendations on additional studies required and potential solutions. From this desktop exercise the engineering team is confident that sufficient information can be collected to inform the design of the pilot structure foundations. The pilot structure will not be built on piles, and due to its smaller size and positioning, potential issues of terrain instability were not deemed to greatly impact its foundation design. Design will be conservative, and will take into account any uncertainties. 

  • Geotechnical field work will start in late spring 2022, along with a topographic survey. This will provide sufficient time to make any required adjustments to the pilot structure. The field work will include a borehole program to establish depth to rock, in-situ ice content/salinity and site-specific thermistor program. Ground temperature will be measured seasonally to determine the depth of the active layer. 

  • The complete geotechnical profile of the site will be necessary for the final building. The final building is estimated to have a ground floor footprint of roughly 2,500 sq feet (total size 3,500 sq feet), and will require a more robust foundation, likely including pilings and significant landscape modification. Community members have suggested taking advantage of the future site slope (5%) to integrate traditional subterranean storage and freezer spaces, whose design will also be greatly impacted by the geotechnical survey findings.

REPORT COMING SOON