Wednesday, March 28, 2012

Somerset Street Reconstruction Part 8: Bridge sidewalks A

This 15-part series on the reconstruction of Somerset Street West finished with the section east of Preston with Part 7, which talked about trees and bike racks. We now turn our attention to the sidewalks on the section between Preston and Breezehill, over the O-Train tracks. Since sidewalks are pedestrian-related, this'll count as my Peds on Weds post for this week.

The drawing shown below was from the very first meeting where this project was introduced to the community. In stark contrast to the Bronson avenue consultation, the project team for Somerset West came to us with a drawing of what it looks like now, and some markers. Since then, they have worked with the community design team to make Somerset into a much improved street.

The sidewalks on the bridge weren't re-done simultaneously, so this photo of the sidewalks on the south side being broken up was taken at the same time that the forms were being laid for the sidewalks on the north side, which had been broken up quite some time before.

Unlike most sidewalks in Ottawa, the ones going over the O-Train tracks are built with reinforced concrete. This meant that they couldn't simply be pulled up by a big digger, but had to be chipped away by jackhammers. Here a few spent jackhammer tips sit amid the rebar.

Since four lanes is far more than needed for the traffic volume on Somerset, the sidewalks can be widened significantly while leaving room for through lanes and bike lanes. You can see the rebar of the original North sidewalks at left, with the base of the new pedestrian lampposts quite a distance from them. The new curb line will be a foot or so further out from the lampposts.

With the bridge closed anyway due to the installation of the pathway tunnel (discussed in part 12), part of the roadway was left paved and fenced to serve as a sidewalk while both sidewalks were dug up.

A bulbout was added between Musca's and the antique store. This had a dual purpose of traffic calming (i.e. to discourage people from using the parking lane as a travel lane) and to provide an opportunity to plant a tree on the north side, where space for trees is lacking. You can see the string and spray paint outlining the bulbout here:

Conduit was run through the rebar under the ground. I suspect this is for the pedestrian-level lights, since it runs from the streetlights (which have power) roughly in the direction of the pedestrian-level lights (which need it).

The concrete was poured, leaving room for a band of decorative red concrete. But in the previous post I alluded to trees going in over the bridge. Since trees need water, and bridges tend to be built to drain water away, how will they do it?

Well, it involves these boxes. Like the conduits for the pedestrian-level lighting, irrigation hose was run between the pits that will hold the trees, formed by these boxes in the sidewalks. As a complicating factor, utilities that had previously been located under the sidewalk had to be either lowered or moved aside to avoid conflict with the trees (because the gas and phone companies tend not to replace trees when they have to dig them up to get under them!)

But these boxes are merely to form the concre—even with irrigation, this size of hole isn't enough for a tree to survive. They will merely be the base for seven-foot long custom-built concrete planter boxes, which were depicted on one of the boards at the public open house. The ends will be angled slightly so that the shape evokes the front of a streetcar, as a reminder that streetcars once ran along Somerset. The result will be a much less hostile environment, where pedestrians are insulated from motor traffic, and the trees will help to break the wind.

The planters, like most of the other street furniture, won't be going in until this coming spring and summer. Until then, the holes have been bricked over for the winter.

In the next post, Bridge Sidewalks B, we'll stay on the brige's sidewalks, and I'll show you a few more tidbits about their design, before launching into the City Centre/O-Train pathway in the final parts of the series.

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