There are more than 9,300 manholes in the city of Hamilton.
Since 2019, the city has been using a tool called “Mr. Manhole” that creates a circular concrete frame around manholes, as well as valve boxes overtop gas and water lines, that help improve the overall condition of the city’s streets.
According to the city, the whole process addresses a longstanding issue of the fast degradation of asphalt around these in-street structures. Also, it will provide additional protection from maintenance activities, like snow plowing.
Hamilton Engineering Project Manager Pat Yingling called this an “exciting” process as it strengthens in-street structures with a durable ring of concrete.
“In the long term, this means that these structures remain level and provide a smoother driving experience longer,” he said. “All while helping better maintain the overall conditions of our streets.”
Engle said Hamilton took this approach nearly four years ago because it was suggested by a subcontractor.
“We approved it as a pilot program to evaluate its performance,” Engle said. “We had observed other communities using it, so we wanted to try it.”
While the concrete frames won’t increase the longevity of the manholes themselves, in addition to the smoother rides, Engle said “it will provide longer life” for the roadways at the manholes and a longer life for the valve boxes “because the concrete will protect the valve boxes from damage.”
Valve boxes are vertical cylinders installed overtop of underground gas and water values, which are used to access these values using a long-handled T-wrench to operate the valves.
The process of installing the concrete circular frames happens after a road is paved. The concrete ring helps to reduce settlement around the manhole over time and helps to prevent water from penetrating underneath the pavement.
The per manhole cost is $800, and $550 for each valve box.
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