Executive Summary:
N/A
Background:
The work consists of relining a culvert and storm water sewer within the City of Windsor limits.
Based on the recommendations of the 2019 Drainage Report, as completed by Landmark Engineers Inc., the existing 2100mm Central Avenue culvert, located at the intersection of Grand Marais Road E and Central Avenue, was found to be in very poor condition and exhibiting heavy corrosion. The consultant engineer identified the possibility that significant soil cavities may be forming underneath the Central Avenue culvert. It was recommended to City Administration, in the 2019 Drainage Report, that the Central Avenue culvert should be reviewed further for relining possibilities.
The Operations department is proactively relining the 1800mm CSP stormwater sewer which outlets to the Wolfe Drain as it is located throughout residential properties, by means of an easement, and poses a future risk to residents in the surrounding area as the sewer ages. This has been on Operation’s agenda for the last 3 to 4 years.
Construction is anticipated to start the week of January 11, 2021 with thirty (30) working days outlined in the contract.
Discussion:
The City of Windsor has contracted Clean Water Works Inc. for the completion of contract 109-20 to reline the Central Avenue culvert and the CSP stormwater sewer that outlets to the Wolfe Drain. A significant portion of this project requires the use of large resin liners to securely take the shape of the existing culvert and sewer.
Based on the size and lengths of both the culvert (2100mm for an approximate length of 62.0 meters) and storm water sewer (1800mm for an approximate length of 170.0 meters), the contractor requires additional time for the liners, and service connections, to be installed, cured, and returned to service. Once the process of installing one section of the liner has begun, it cannot be stopped until completed. This is because during the installation of the liner, any active connections to the sewer will be obstructed until the Contractor can safely get their appropriate machinery (i.e. robotic cutter) into the culvert/sewer to re-open the connection.
The following factors contribute to the extra time required to complete the work of the project based on the existing diameter of the host pipe and the wall thickness of the liners:
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Installation of liner (3 to 4 hours)
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Curing resin liner either by water or air (6 to 8 hours)
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Cool down period (4 to 5 hours)