MANHOLES – Tidemore Ave.
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Location:
Tidemore Ave., Etobicoke, ON
Repair Types:
Active leak stop, cold joint repair, surface restoration, waterproofing, weeping tile installation.
Project Background:
A property line manhole located in front of a plastic production facility designed to collect residues from the plant. This maintenance chamber was surrounded with soil oversaturated with ground water which caused it to always be full of water, in danger of over exceeding its capacity.
ISSUE
Water infiltration into the manhole. Structural failures.
Cause
Structural aging due to exposure to the environment.
Solution
Since the ground water could no longer penetrate the manhole, its level went up, and it started leaking from above. To eliminate this issue, the contactor was instructed to dig a trench around the manhole and install a weeping tile, to redirect the excess water into a nearby ditch. Digging the soil in -20°C weather was impossible, though, and this challenge was overcome by using a chipping gun to remove the soil, which was to be put back in after the weeping tile had been installed.
To be able to waterproof the manhole from the inside (walls and floor), all the water had to be pumped out first. Then the concrete surface was to be repaired, as specified in our design document: chipping was done to prepare the surface to be primed before black cement was to be applied to stop any leaking. Then a fast-setting cement and parging mix were to be used. The surface had to be dried with torches, and a waterproofing coating installed.
