An engineering report by Golder Associates recommends the City of Ottawa shorten its downtown light rail transit (LRT) tunnel following the first phase of geotechnical investigations.
In the report released in late December, engineers recommended the planned 3.2km tunnel between LeBreton Flats and the University of Ottawa be cut by 600 to 900m. Rock samples from 34 boreholes drilled between May and August 2010 show the ground to be as expected except for in one area of the alignment where bedrock is 2 to 10m deeper than anticipated.
The design modification would have Campus Station, one of four underground, on the surface. Shortening the tunnel should not change the expected CAD 2.1bn (USD 2.07bn) cost, which was approved by the City Council in June 2010.
Phase two, consisting of another 90 boreholes, finished at the end of the year and that report will be released in April. The third and final phase will drill from April to July 2011.
