99th Avenue Sanitary Trunk Bypass

The DSD design was a secant pile compression ring system that was 9.0m in diameter with an excavation depth of 30.6m. The scope of work included installing 880mm diameter fully cased secant piles with location assistance provided by a reinforced secant pile guide wall. The secant piles were in installed using a Liebherr LB36 drill rig and the RT-80 crane. After secant pile installation, a reinforced concrete capping beam was installed at grade. The shafts were excavated by DSD & Kichton Contracting using a combination of small excavators, dirt bins & hoist crane, and Kichton’s new telescopic clamshell excavator. At the base of the excavations DSD installed a reinforced concrete slab with a sump.

The main challenge was the shaft depth and its effect on the secant pile alignment. To correct the secant pile deviation in portions of the lower sections of the shaft DSD designed and installed reinforced shotcrete. Overall the client and the owner were very pleased with Double Star’s commitment to overcome the challenging shaft depths, dedicating equipment, and workforce to ensure the projects schedule milestones were met.