The community of Ste. Agathe is protected by a clay ring dyke. Summer rainfall is conveyed through the ring
dyke via gravity drainage infrastructure. Spring snowmelt and rainfall runoff is pumped out of the ring dyke when
high river levels prevent gravity drainage. Five (5) valve chambers and three (3) gravity structure gate chambers
are closed to prevent flooding in Ste. Agathe during high river levels. Gravity structure gate chambers are
comprised of a cast-in-place concrete chamber with a concrete divider wall. The gravity structure gate chambers
contain a flap gate and a sluice gate.
During a recent condition assessment inspection, AECOM identified damaged concrete at Gravity Structure 2
(GS-2). The concrete damage appears to have been created by concrete anchors installed near the edge of the
concrete divider wall, causing portions of the concrete to pop. The released anchor bolts have subsequently
caused misalignment of the sluice gate operator stem and difficulty operating the sluice gate. To repair damaged
concrete, the existing grating must be removed. After concrete repairs are completed, the grating can be
replaced at a slightly lower elevation to remain within competent concrete. Then the sluice gate and valve stem
operator must be repaired, realigned, and shortened to fit with the lowered grating. A cash allowance has been
included to cover unknown material costs associated with the sluice gate repairs.
The work includes the following:
- Remove sluice gate operator, existing grating, structural beams, and concrete attachments.
- Inject cracks within the concrete divider wall with epoxy.
- Sawcut, chip out, pressure wash, and repair damaged concrete on divider wall.
- Inspect and repair existing sluice gate, guides, supports, stops, bolts, nuts, etc.
- Re-install existing grating, structural beams, and concrete attachments 150 mm lower than existing.
- Re-install sluice gate operator at 150 mm lower deck and ensure proper sluice gate operation.
The Work is fully detailed in the reference documents on the following page of this Tender.
