To address some of these questions, I spoke with Mac Logan, director of Transportation Infrastructure for The City of Calgary. Logan says that it's a misconception that the bridge could have been built for $5 million. While The City has built pedestrian bridges for approximately that cost in the past, in this case, it wouldn't have been possible.
Logan says that there are a number of factors that came into play in the cost of Peace Bridge, including the width of the Bow River at the point of crossing (the location was selected based on the amount of pedestrian and bicycle traffic).
Secondly, The City wants to maintain the usability of the helipad located in the area, which is used predominantly by HAWC1 and STARS. Essentially what that means is that the bridge can't be suspended by overhead towers, which would restrict air space clearance.
Finally, Logan said that The City wants to ensure that the bridge minimizes the potential environmental impact on the Bow River, so the bridge was designed so that it would not have any piers in the river.
Of course the bridge will have to be built to withstand Calgary's once in a 100 year flood cycle (hopefully we're good until at least another 100 years after the flooding of 2005).
Peace Bridge will cost approximately $30,000/m2 which is lower than similar pedestrian bridges in other municipalities, including Edmonton's pedestrian bridge that will cost $33,000/m2.
The vast majority of the funding for Peace Bridge comes from the Province's Municipal Sustainability Initiative, which is collected by the province from oil and gas revenues and granted to municipalities across Alberta for projects that meet the demands of growth. The City will only be contributing $125,000 towards the project - 0.5% of the total project cost.
Check out my interview with Mac Logan, The City's director of Transportation Infrastructure below.
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Thanks for this. It would be nice to hear the estimations of an independent engineer. I'm not convinced it is so important not to have any piers in the river if that renders the project cost-ineffective.
ReplyDeleteWe don't need a Peace Bridge. $24 Million waste of our money.
ReplyDelete$18 million for construction with no piers, but I'd be interested to know what it would cost with a pier or two.
ReplyDeleteThis is one of those decisions that's pushed by the environmental movement and the unusual seflsih misconception that humanity is powerful enough to do serious damage to the place we live in by dropping some concrete in a river. I imagine it came from a fairly high level and probably not from someone who is an engineer. An engineer knows that you can build a bridge with piers for significantly less money, but has been assigned a task to keep the "environmental impact" low. It is the policies built on excessive idealism and guilt that makes the project cost-ineffective, not the engineering behind it.
I don't understand what "Of course the bridge will have to be built to withstand Calgary’s once in a 100 year flood cycle" is supposed to mean in the context of convincing us this is a worthwhile expenditure. I hate to rain on the parade again here, but in the very 2005 flood damages report that is being referenced in this blog, the City of Calgary is said to have incurred approximately $17.2 million in damages. The VAST majority (about $10 million) was as a result of infrastructure and asset damages incurred by Parks, who owns the majority of the assets along the river banks.
A total of $2.5 million in damages is reported to have been attributable to road bridges and storm outfalls in the 2005 "once in a 100 year flood." So says the City's very own report. It's not exactly fair to say that we could build and repair three identical bridges WITH piers for the next 500 years worth of floods for the same price--but, then again, that's only assuming that a bridge with fewer grounded supports would be economically invulnerable to flooding. :^)
Sara,
ReplyDeleteThe elimination of piers doesn't have as much effect on the cost as one would think in this case. Although a lower cost would ultimately be achieved, the difference is not as staggering as it would be in a vehicular bridge.
When it comes to ped bridges, most of the loads exerted on the structure can be attributed to environmental factors such as snow/rain, wind and water as well as dead loads (weight of the structure itself) with very little being contributed to the actual traffic on the bridge. The design of this bridge in particular is such that even dead loads are minimized which equates to a relatively small vertical force. Piers, in general are placed to reduce the shear force in the bridge deck and girders which is a vertical force in a bridge. The reduced vertical load really reduces the effectiveness of a pier as extra construction costs are incurred from the pier construction anyway (for the span of this bridge, pier construction would cost around $3-4 million). All-in-all, we probably could have saved $6-8 million by building a concrete bridge with piers which can really come down to the cost of building something that is more unique rather than just another ped bridge.
The one thing I don't really get is why we had to go overseas to have this engineered when we have all the talent we need right here in Calgary. We are not one of the most educated cities in North America for nothing. I see the 22% engineering fees as a little steep. This is where we could have saved a million without sacrificing anything design/performance related.