One of the most difficult types of construction project there can be is a project that is in a source of water. Construction in water is notoriously difficult and dangerous, yet it is necessary. The US simply could not function if there was no other way to cross expanses of water than ferries, and the viability of some states – for example, Florida – would be severely tarnished if the building of bridges was not a possibility.
Thankfully, mankind has been building bridges for centuries. From humble bridges across a stream, to the world’s longest bridge (the Danyan-Kunshan Grand Bridge that links Beijing to Shanghai in China, which is 540,000 feet or 102.4 miles in length), bridges have become such a common site across our landscape that we barely take any notice of them.
What Happens When a Bridge is in Such a Bad State of Repair it Needs to be Demolished?
It’s a sad state of affairs that a huge percentage of the bridges in the United States are in a very poor state of repair. That’s because the ‘golden age’ of bridge building has been over for a few decades. When you build a bridge over a river, for example, you seldom have to build another one next to it, or even have the available funds to do so. Most of the bridges in the United States were built to deal with the volume of traffic at the time, and that volume of traffic has increased many-fold over the last one hundred years, which means that the older the bridge, the less it is capable of withstanding the demands of the traffic that it encounters.
So, instead of waiting for a bridge to fail (which of course has potentially disastrous consequences), the necessary repairs are made or, as is more likely given the age of many of the bridges in the US, the bridge is demolished and a replacement built, either at the same site or close to it.
Bridge Demolition is a Much Smoother Process When You Use Inflatable Cofferdams
Of course, a bridge demolition project is one that is in dynamic water – which is water that is flowing. You may think that is not a problem when it comes to bridge demolition – you can simply blow up the bridge and the water will carry the debris away, but if only life was that simple! Filling a source of dynamic water with all kinds of bridge debris is dangerous and illegal, as you might suspect.
The safest (and legal) way to conduct a bridge demolition is for the bridge to be isolated from the water. This can be done in one go by damming the water on both sides, to create a dry working environment do that the bridge can be removed. However, this is only possible in a very small number of cases where water flow is minimal. In most cases damming dynamic water will cause problems upstream.
The solution is to dam areas of the bridge section by section, allowing the water to maintain its flow. Inflatable cofferdams are ideal for this, as they can be deployed and then redeployed quickly. You isolate an area of the bridge, remove it, then remove the cofferdam and deploy it for the next section, and so on. You repeat this process until the entire bridge has been removed.
To learn more about how inflatable cofferdams can aid the bridge demolition process, please contact our team here at Dam-It-Dams. We can help ‘bridge’ the gaps in your knowledge when it comes to using cofferdams for bridge demolition.