(5) Helical Piles were installed to support a concrete staircase. Helical piles were chosen to support the staircase due to the poor soil conditions existing onsite. All 5 piles were 4.5” in diameter with a single 18” diameter helix. The piles were driven 10’ below existing grade. Since these helical piles were installed adjacent to live train traffic in the Toronto area, the install was frequently interrupted; installation was shut down before any train would enter the station and would remain on standby until the train completely left the station.