PERI was tasked with providing solutions for various aspects of the job, including: foundations, walls, draft & small tubes, the intake transition, and a number of beams and slabs. TRIO, in conjunction with CB Platforms, was used to cast the foundation slab and walls, while a combination of VARIOKIT and MULTIPROP was used for slabs and tubes. Due to the working height (approximately 14m above grade) and depth of some slabs (900 mm), SB Brace Frames were used in a horizontal position to support MULTIFLEX shoring and to create a safe working platform for site personnel. This also had the added benefit of allowing the contractor to simultaneously finish the walls below the slab, as there was no shoring obstructing or preventing access to the area.
The Draft Tube area in particular presented a unique challenge due to the transition from a circular to rectangular section. By utilizing VARIOKIT with a combination of wooden gussets, PERI proposed a solution whereby the tube shape was cast in two pours, with the shutter being used for both the bottom and top section. Based on PERICAD designs completed by PERI’s Engineering Department, wooden gussets were precisely fabricated using CNC technology. PERI Assembly Specialists constructed formwork elements consisting of VARIOKIT components. VARIOKIT was selected as the formwork base because of its standardized and rentable components resulting in a fast, safe and cost-effective system. The pre-assembled formwork units were shipped, from Bolton, directly to the job site in Dokis, Ontario.
After the units arrived on site, PERI Site Demonstrators supported Miller’s site personnel for final assembly of the units, helping them to achieve maximum efficiency and safety.
PERI UP stair towers were used to provide an entry/exit point to the 20m deep excavation, while also providing a safe means of access to the various CB platforms for the upper levels of walls.