Background

The Rainy River Solar Project which is located near Emo, Ontario will produce enough clean energy to meet the needs of over 3,900 households. The solar power generated at Rainy River will be sold to the Ontario Power Authority under three power purchase agreements.

TBT Engineering’s Role

TBT Engineering Limited in association with  Ozaanaman Engineering was commissioned to evaluate the existing site roads at the Vanzwolf Solar Farm site as well as assess the general site conditions, review the current road design recommendations for the project, and provide general recommendations for improvements to the road transportation network within the Vanzwolf site.

Investigation (Methodology)

The initial evaluation of the existing site roads determined that a variation of crushed sub-base aggregate (Granular B Type II) was present on the site.  Some areas demonstrated a very coarse crushed Gran BII and other areas a more fine graded Granular BII.  Varying thicknesses of material were observed.  Based on visual observations a combination of non-woven geotextile overlain with a geogrid membrane was placed beneath the Granular BII.

The performance of the existing road varied from acceptable to poor.  Evidence of wheel track rutting from slight to extreme was identified with localized areas of complete failure of the geosynthetic layers and punching of underlying native soils into the granular sub-base.

Result Reporting

Based on the anticipated site use and projected loadings and given the nature of the existing soil condition it was demonstrated using MTO NWR granular base road design table that the minimum depth of granular roadbed materials for the project should be 750 mm over top of the geotextile and geogrid.

Further engineering recommendations for the current road network at Vanzworf site where also made as where general recommendations for the Morley and Dave Rempel sites, where no road work had yet taken place.