Humans have been engineering bridges ever since we first came across a stretch of water that didn’t have a natural bridge for us to cross.
And while the earliest bridges that humans created wouldn’t be able to cut it in our modern world, bridge design and engineering has changed and shifted throughout the centuries. Today we have some of the largest and most beautiful bridges ever created, and many of them take advantage of cantilever technology.
All the same, there are definitely some big benefits and disadvantages to cantilever bridges – and we are going to highlight those below!
List of The Pros of Cantilever Bridges
1. The biggest advantage that cantilever bridges bring to the table (an advantage that they have been leveraging since the first was created in 1866) is the fact that they offer uniform bridge construction and a much more streamlined production process that cuts time and costs considerably.
2. Instead of having to build bridges from a standpoint on both sides of a stretch of water, cantilever bridges take advantage of a single side support in the middle of the bridge itself. These peers help share the load from the main columns that extend outward, and the entire system works like a big springboard.
This allows for a very uniform bridge construction throughout, not only creating a simplified process of construction but also making the bridge itself very visually appealing. Some of the world’s most famous bridges are cantilever bridges and it isn’t difficult to see why!
3. It also doesn’t hurt that these kinds of bridges can be constructed in pieces or segments and then assembled later on in place, rapidly speeding things up as well.
List of The Cons of Cantilever Bridges
1. At the same time, cantilever bridges require a very heavy structure to balance the load throughout and to take advantage of the unique engineering without spring boarding the vehicles or people on the bridge every time someone enters one side of the bridge or the other.
These incredibly heavy structures cannot be constructed everywhere, as they need very solid footing and aren’t acceptable in earthquake prone areas.
2. On top of that, a tremendous amount of turning stress (called “negative moments” in the bridge building industry) occur during construction, and the segmented pieces of the bridge have to be constructed to exacting specifications off-site if they are going to fit together on site seamlessly.
This can prove to be a bit of a challenge, and there have been plenty of cantilever bridge projects that have been delayed or had their budget overrun because of off-site constructed segments that were not matching up with the rest of the bridge.