Background Information and Challenge
The George Massey Tunnel Replacement project was highly anticipated for commuters in the lower mainland and would require a transformer pad relocation. The existing tunnel was to be replaced with a bridge to improve congestion on the hectic highway 99. BC Hydro’s existing infrastructure at the tunnel needed to be moved to construct the new bridge.
Two transformer pads, one on the north and one on the south side of the tunnel, had to be relocated before the construction works could commence. This put their company in a challenging spot to design something quickly that would satisfy their requirements and turn it around quickly for construction to begin. The area above the tunnel contained weak soils, and the transformer pad relocation would need to handle heavy truck traffic loads and withstand seismic activity.
Layfield suggested using a high strength woven separator fabric, HP570, along with a 6″ Presto GEOWEB® product for both the access roads and transformer pads to meet the loading and seismic requirements. From there, Layfield provided the BC Hydro engineers with a preliminary design for both areas, which they could include in construction drawings.
The transformer pad relocation was successful. BC Hydro was able to take preliminary design and stamp off on their final construction drawings for this project in a matter of 2 weeks from the first meeting. The products were ordered and on-site two weeks later for the beginning of the project. BC Hydro’s Construction division installed the product on both sides of the tunnel in just a few days. They commented on the ease of installation and how quickly it all went in and were very happy with the result.