Types of Load on Structures

Loads are forces or other actions that cause stresses, deformations, or accelerations on a structure. These loads can be due to environmental conditions, usage, or the materials'  weight. Correct identification and calculation of these loads is important for designing structures that are safe, efficient, and cost-effective. Various factors influence the magnitude and direction of these loads, such as the building's location, purpose, and design.

6 Different Types of Loads in Construction

1. Dead loads

Dead loads are the constant forces on a building caused by the weight of its own parts, like walls, floors, roofs, and beams. Since these weights don't change over time, dead loads are the easiest to predict of all load types. It's important to accurately calculate dead loads because if they're underestimated, it can lead to serious structural problems.

2. Imposed loads

Imposed loads, or live loads, are forces that change over time. They include the weight of people, furniture, vehicles, and other items that move within a building. Unlike dead loads, imposed loads aren't constant and can vary based on how the building is used. 

For example, the live load in a home is different from that in a commercial building, where you might have heavier items like office equipment and more foot traffic.

3. Wind loads

Wind loads are horizontal forces that the wind applies to a building. These loads are especially important for tall buildings, bridges, and other structures with large surfaces exposed to the wind. 

The effect of wind loads varies based on factors like wind speed, direction, and the building’s height and shape. Engineers need to account for wind loads to prevent problems like swaying, vibrations, or even collapse in extreme weather conditions.

4. Snow loads

Snow loads are vertical forces that build up when snow accumulates on a structure. This type of load is important in areas with heavy snowfall, where the weight of the snow can be significant. 

Roofs, in particular, need to be designed to handle snow loads to avoid overloading and potential collapse. Factors like the roof’s angle, the type of snow, and the building’s location play a key role in determining how much snow load a structure can handle.

5. Earthquake loads

Earthquake loads are forces caused by the shaking of the ground during an earthquake. This type of load is unpredictable and can be very damaging. Buildings in areas prone to earthquakes need to be designed to handle these forces, which can cause both side-to-side and up-and-down shaking. 

To make structures more earthquake-resistant, engineers use flexible materials, strong foundations, and shock absorbers to help absorb and manage the energy from seismic waves.

6. Special loads

Special loads are forces that don’t fit into the usual categories like dead, live, wind, snow, or earthquake loads. These can include things like temperature changes causing thermal loads, impacts from vehicles or machinery, and pressure from the soil. 

Special loads are often specific to certain projects and need tailored engineering solutions. For example, buildings near industrial areas might need to account for impacts from explosions or vibrations from nearby machinery.

In addition to these main load types, it's important to understand load-bearing structures. These are structures that carry the building's weight and different types of loads, passing them safely to the foundation.