Doublestar Drilling helps PCL Construction reduce high-volume traffic in Saskatoon
Supplied by Doublestar Drilling
Doublestar Drilling was awarded the City of Saskatoon Interchange, Stone Columns Project by PCL Construction. These interchanges will help reduce the current high-volume traffic in these areas. Several alternatives were evaluated during project pursuit and the design team ultimately elected to proceed with the embankment stabilization through the use of compacted stone columns.
First the stone columns were pre-drilled six metres by a Soilmec SR-30 to be able to set the temporary casing, then the casing was driven to the required depth using the crane mounted vibratory hammer. Doublestar used its Liebherr HS855HD crane to hoist and install the temporary casing prior to drilling out/excavating the stone column to the design depth. The stone column was excavated using the firm’s Liebherr LB28 drill and was backfilled with granular material and finally compacted by vibrating the temporary casing up to the accepted compaction. Further compaction of the stone column as required was done with a vibratory lance.
Doublestar completed 450 each of 1,800 mm and 2,100 mm diameter stone columns. They averaged a depth of 14 metres and the majority of the stone columns were cased to 11 metres.
Due to the project being only a few metres away from existing major roadways, extreme safety measures were taken. Doublestar worked with PCL on the pre-project planning to ensure no steps were missed and everyone was on the same page.
The successful execution of this project provided improved slope stability and bearing capacity for support of the MSE walls, reduced magnitude of settlement and increased settlement rates of the embankment construction.