I've noticed that in many states, there is a strong preference for either using embankments to elevate ramps in interchanges, or using piers. In some states, the preference for one makes sense (Louisiana using piers due to soil conditions), but others are less intuitive (New Jersey preferring embankments, even in swamps; Texas using piers in practically all new construction)
Any reason for why states might choose one over the other, all else being equal?
I would guess - and this is just a guess - that embankments would be less maintenance than ramps (which I would consider to be a type of bridge in a sense).
Quote from: Mr_Northside on July 14, 2016, 06:12:12 PM
I would guess - and this is just a guess - that embankments would be less maintenance than ramps (which I would consider to be a type of bridge in a sense).
And the reconfiguration of the Turcot interchange in Montreal, the ramps are currently on piers but they'll be replaced with ramps who'll havve parts on embankments.
In my experience, piers are typically the result of constrained right-of-way, poor soil conditions, or low elevation. As a general rule, embankments are less expensive than piers/longer bridges.
I remember reading that Ontario prefers embankments because it gives you a place to put snow, and elevated ramps are more likely to freeze. These wouldn't be issues in Texas.
Quote from: 7/8 on July 16, 2016, 11:28:52 AM
I remember reading that Ontario prefers embankments because it gives you a place to put snow, and elevated ramps are more likely to freeze. These wouldn't be issues in Texas.
Which is probably why most northern states do the same. Snow needs to go somewhere and bridge decks freeze before pavement on soil. Also, salt will eat away at the concrete and corrode the steel, an issue that isn't as prevalent with embankments.
New York, for example, uses embankments unless it is an elevated highway with stuff passing underneath.
With MSE walls, which have been used extensively in the past 2 decades, embankments will likely be more common, as they can be constructed with less ROW and, while more expensive than a traditional embankment, they are still cheaper than bridge construction/maintenance/replacement.
Quote from: cl94 on July 20, 2016, 12:05:57 AM
Quote from: 7/8 on July 16, 2016, 11:28:52 AM
I remember reading that Ontario prefers embankments because it gives you a place to put snow, and elevated ramps are more likely to freeze. These wouldn't be issues in Texas.
Which is probably why most northern states do the same. Snow needs to go somewhere and bridge decks freeze before pavement on soil. Also, salt will eat away at the concrete and corrode the steel, an issue that isn't as prevalent with embankments.
New York, for example, uses embankments unless it is an elevated highway with stuff passing underneath.
With MSE walls, which have been used extensively in the past 2 decades, embankments will likely be more common, as they can be constructed with less ROW and, while more expensive than a traditional embankment, they are still cheaper than bridge construction/maintenance/replacement.
The Gardiner Expressway in Toronto and the Turcot interchange in Montreal are great examples of corroded concrete. I remember seeing the rebar exposed in Montreal, and even nets on the overpasses the keep chunks of concrete from falling! :wow: I wish I could've taken pictures, but I was driving.
Luckily the Turcot is being fixed now.