In November 2017, Pomerleau awarded Doublestar Drilling (DSD) the Douglasdale-McKenzie Lake Slope Stabilization & Pathway Project located in Calgary, Alberta, on the banks of the Bow River. Doublestar was responsible for supplying & installing 236ea CIP Concrete Piles, 234ea Rock Anchors, 225ea Micropiles, 800m2 of Shotcrete and the installation of geotechnical instruments; Slope Inclinometers & CSL Tubes.
This diverse scope of work required immense amount of pre-project planning between Doublestar and Pomerleau to ensure that the design requirements, safety and site specifications were compliant with The City of Calgary Standards. Due to the environmental sensitivity factors of this project, DSD took every precaution available to guarantee that all risks were mitigated to prevent any potential environmental impacts. Equipped with special sound dampeners on the Kelly Bars and the engine silencer kits on the Liebherr drilling rigs, noise levels were minimized to the surrounding residential communities. It was critical for the design that the equipment didn’t exceed 200Kpa of downward pressure on the drilling platform; therefore DSD carefully chose their Liebherr Drill Rigs and Crawler Crane to ensure this requirement was met throughout the project.
DSD first completed the 165mm diameter Micropiles that were installed in just 4 months with a 32mm DSI Thread bar, using our Davey Kent 725 and Interoc AN150 Drill rigs. Doublestar equipped their rigs with solid stem and air rotary tooling applications in order to complete ~3,465m total drilled depths.
Doublestar selected the Liebherr LB-28 drill rigs to complete the CIP Piles due to their powerful torque and crowd capabilities, eliminating any need for vibratory and/or slurry drilling methods and utilized their Liebherr HS855 HD Crawler Crane for lifting and tying cages onsite. In just over 6 months, DSD’s piling crew completed the 236ea 914mm diameter CIP Piles to depths of 32m and moved their focus onto the remaining rock anchors and shotcrete.
Prior to drilling, Doublestar completed pre-production rock anchors which were stressed up to 200% of the design load, to determine the remaining anchors design capacity and validate the anchor bond parameters. Now going forward, all anchors are to be Proof Tested to 133% of the Design Load of 650kN and installed with a 46mm Double Corrosion Protected (DCP) thread bar. The 150mm diameter anchors are being installed to 32m lengths, which will be completed by Doublestar’s HUTTE HBR610 drill. Currently with ~95 rock anchors completed to date, DSD continues to prepare the installation of the remaining anchors and shotcrete, to complete this project on time and on budget.