The Structure
The Brooklyn Bridge is a roadway that connected Manhattan and Brooklyn before they became greater New York. It is made out of steel and granite and timber because they are strong stable building materials. The timber was only used for the caissons. The granite was used in caissons, anchorages, and the towers while the steel was used for the web truss which made it 6 times stronger and for for maximum stability so it does not collapse into the East River.
Forces acting on the Brooklyn bridge
The forces that are acting on the Brooklyn Bridge are tension, compression and there are dead (gravity, materials, ect.) and live loads (humans, cars, ect.). The tension is in the steel cables, suspenders, and backstays. The compression is in the towers. Some external forces that are acting on the bridge are gravity and the materials used to build it (dead load) as well as cars, trains, cart and even elephants (live load) are external forces that the bridge deals with.
How Brooklyn Bridge deals with forces
The Brooklyn Bridge deals with forces in many different ways. One way is strong towers and a web truss. It needs the strong towers to keep the bridge from collapsing into the East River and it needs the web truss to hold up the road and deck and stop it from snapping and breaking. The bridge specifically needed to be resistant to torsion and shear force. This is where the web truss comes in. Because the bridges from this time were known to fail under strong winds, Roebling needed a new way of creating wind resistant bridges. The web truss helps the bridge become more resistant to shear force and torsion.
Bumps in the road
The Brooklyn Bridge sustained some damage but was quickly repaired. In the original construction, two caissons were damaged, one by a fire and one by an unexpected blast. Luckily no water ended up seeping in on either occasion, so construction continued as per normal. Another problem that occurred was that a cable snapped from it's anchorage and crashed into the river. They replaced this cable and this problem never happened again. Also on March 13, 2012 a crane hit the bottom of the bridge and twenty feet of canvas and sheet metal was damaged. It was fixed and no other damage was reported.