Special precautions for specific ground conditions
Submitted by Doublestar Drilling
Doublestar Drilling was awarded the large-scale condo development project, West Village, in April 2017 by Cidex Group, which is located on the west entrance of Calgary’s downtown core.
Due to the successful collaboration between Doublestar Drilling (DSD) and Cidex Group earlier in 2017 on The Hat project in the East Village, both parties were eager to be working together once more.
DSD equipped their crews with three large piling rigs, two Liebherr LB-28 rigs and one Liebherr LB-24 rig, to ensure the client’s schedule was met. To further prepare themselves, DSD took special precautions such as segmental casing to confirm the best drilling practices were being used for this job’s specific ground conditions. A total of six hundred and thirty-eight 880-mm diameter piles were installed during the four months of piling.
Due to the high-density work area, coordination of traffic to ensure safe access and strategic organization of all movement to reduce congestion and minimize any traffic flow impacts was a main priority. DSD minimized noise levels to reduce any impact to the surrounding residential towers with special sound dampeners on the Kelly Bars, as well as engine silencer kits on the Liebherr drilling rigs. Idling time was restricted only to meet production requirements. Their well maintained Liebherr drilling rigs have the latest engine technology, thus further reducing emissions.
Anchor drilling began in early July and the company has currently completed a third of the installations. Their crew is using the Davey Kent 725 rig and the Interoc AN150 rig to install 36-mm Dywidag bar up to 54 feet in length. All of the tie-back anchors will be stressed at 125 per cent of their working load, which at the bottom row will be tested up to 700kN. A detailed plan and design was created between DSD and EBA Engineering, allowing the piling and anchors to overlap by four weeks. This resulted in requiring only two rows of tie-back anchors along any shoring wall. This considerably reduced the costs of the shoring and the project timeline for the client. 