Bridges are a feat of engineering that have been around for thousands of years. In fact, the Romans are actually credited with building some of the most durable bridges in the world, such as the Caravan Bridge, which dates back to 850 B.C! Civil engineering is an engineering discipline that focuses on the physical and naturally-built environment like roads, canals, dams, airports and even bridges. Read on as we go over everything there is to know about bridges and the science behind how they work…
There are forces at work all around us every single day, such as gravity which prevent us from floating above the ground, and these ensure that constructed infrastructure remains where the construction workers left it. Although gravity isn’t such a big deal for general buildings and skyscrapers because the ground underneath already pushes it back up again, a bridge is a floating deck that has no support directly underneath. In fact, a bridge will weigh more when the length of the dock is increased which is why its load must be carefully calculated by structural and construction engineering experts in order to prevent them collapsing.
This is carried out by balancing two different forces in order to ensure that they work hand-in-hand rather than fighting against one another: compression, a pushing force that acts inwards, and tension, a pulling force that acts outwards. The load of the bridge is channelled onto abutments, the engineering term for the sub-supports at either end that work in order to ensure that the bridge will remain upright.
When a bridge is unloaded, it only has to support its own weight which means that the tension and compression forces are static. Unfortunately, it isn’t always as simple as this as bridges must be able to carry varying weights that can change from one moment to another which means that they have to be designed in order to support cars, people or trains safely. Furthermore, the design of a bridge should also factor in the environment as earthquakes and floods can be catastrophic, and strong winds often introduce another force, known as torsion, when it comes to suspension bridges.
The sub-discipline that deals with the construction of bridges is known as structural civil engineering, and the experts that specialise in this field must ensure that a completed bridge is able to withstand impeccable loads without collapsing. After all, industrial bridges are used by cars that often weigh around 2500lb each! To speak to a civils contractor about your structural engineering needs, get in contact with a member of the Millgrove Construction team today!
