Architects and engineers design earthquake-proof buildings through flexible foundations, damping, vibration deflection technology, shear walls, cross braces, diaphragms and moment-resisting frames. These innovations are essential for ensuring maximum stability and safety for the patrons of such buildings.
Throughout history, we’ve built impressive structures and cities, only for them to succumb to the forces of nature. Earthquakes are one of the Earth’s most destructive forces — seismic waves throughout the ground can destroy buildings, take lives and cost tremendous amounts of money for loss and repair.
According to the National Earthquake Information Center, there are an average of 20,000 earthquakes each year —16 of them being major disasters. On August 14, 2021, a magnitude 7.2 earthquake struck the southwest region of Haiti and killed over 2,000 people. As with other earthquakes, much of the damage was caused by buildings collapsing with people inside them.
Unfortunately, earthquakes like this can happen at any moment in earthquake-prone regions — making earthquake-proof buildings essential all over the world.
Over the past few decades, engineers have introduced new designs and building materials to better equip buildings to withstand earthquakes. Read on or skip to the infographic below to learn how earthquake-proof buildings are designed today.Table of Contents
Table of Contents
- How Earthquakes Impact Buildings
- 4 Methods for Constructing Earthquake-Proof Buildings
- Earthquake-Resistant Materials
- Earthquake-Proof Buildings FAQ
- Great Construction Starts With Great Equipment
How Earthquakes Impact Buildings
Before we look at the features of earthquake-proof buildings, it’s important to understand how earthquakes impact human-made structures. When an earthquake occurs, it sends shock waves throughout the ground in short, rapid intervals that extend in all directions. While buildings are generally equipped to handle vertical forces from their weight and gravity, they cannot traditionally handle side-to-side forces emitted by quakes.
This horizontal movement vibrates walls, floors, columns, beams and the braces that hold them together. The difference in movement between the bottom and top of buildings exerts extreme stress, causing the supporting frame to rupture and the structure to eventually collapse.
4 Methods for Constructing Earthquake-Proof Buildings
To design an earthquake-proof building, engineers work to reinforce the structure and counteract a potential earthquake’s forces. Since earthquakes release energy that pushes on buildings from one direction, the strategy involves having the building push the opposite way. Here are some of the methods used to help buildings withstand earthquakes.
1. Create a Flexible Foundation
One way to resist ground forces is to “lift” the building’s foundation above the earth through a method called base isolation. Base isolation involves constructing a building on top of flexible steel, rubber and lead pads. When the base moves during an earthquake, the isolators vibrate while the structure remains steady. This effectively helps to absorb seismic waves and prevent them from traveling through the building.
2. Counter Forces with Damping
If you’re familiar with shock absorbers used in cars, you might be surprised to learn that engineers also use a version of them in earthquake-resistant buildings. Similar to their use in cars, shock absorbers reduce the shockwaves’ magnitude and help reduce pressure on the building. They accomplish this in two ways: vibrational control devices and pendulum power.
Vibrational Control Devices
This method involves placing dampers at each level of a building between columns and beams. Each damper consists of piston heads inside a cylinder filled with silicone oil. When an earthquake occurs, the building transfers the vibrational energy into the pistons, which push against the oil. The energy is then transformed into heat, dissipating the force of the vibrations.
Pendulum Power
Another common damping method is pendulum power, used primarily in skyscrapers. To implement this, engineers suspend a large ball from steel cables that connect to a hydraulic system at the top of the building. When the building begins to sway, the ball acts as a pendulum and moves in the opposite direction to stabilize the building. Like damping, these features are tuned to match and counteract the building’s movement in the event of an earthquake.
3. Shield Buildings from Vibrations
Rather than just counteracting forces, researchers are experimenting with ways buildings can deflect and reroute the energy from earthquakes altogether. Dubbed the “seismic invisibility cloak,” this innovation involves creating a cloak of 100 concentric plastic and concrete rings and burying it at least 3 feet beneath the foundation of the building.
As seismic waves enter the rings, ease of travel forces them to move through to the outer rings. As a result, they are essentially channeled away from the building and dissipated into the ground.
4. Reinforce the Building’s Structure
To withstand collapse, buildings must redistribute forces that travel through them during a seismic event.
Shear walls, cross braces, diaphragms and moment-resisting frames are central to reinforcing a building.
- Shear walls are a useful building technology that can help transfer earthquake forces. Made of multiple panels, these walls help a building keep its shape during movement. Shear walls are often supported by diagonal cross braces made of steel. These beams can support compression and tension, helping to counteract pressure and push forces.
- Cross braces attach to a building’s frame by bracing stud to stud in an X pattern to increase load capacity. The use of cross-bracing keeps buildings stable against high winds and seismic activity.
- Diaphragms are also a central part of a building’s structure. Consisting of the building’s floors, roof and the decks placed over them, diaphragms help remove tension from the floor and push forces to the building’s vertical structures.
- Moment-resisting frames provide additional flexibility in a building’s design. These structures are placed among a building’s joints and allow columns and beams to bend while the joints remain rigid. Thus, the building can resist the larger forces of an earthquake while still allowing designers the freedom to arrange building elements.
Earthquake-Resistant Materials
While shock absorbers, pendulums and “invisibility cloaks” may help dispel the energy to an extent, the materials chosen for a building are equally responsible for its stability.
Steel and Timber
For a material to resist stress and vibration, it must have high ductility, which is the ability to undergo large deformations and tension. Modern buildings are often constructed with structural steel, a component that comes in a variety of shapes and allows buildings to bend without breaking.
Timber is also a surprisingly ductile material due to its high strength relative to its lightweight structure.
Innovative Materials
Scientists and engineers are developing new building materials with even greater shape retention.
These innovative materials include:
- Shape memory alloys can both endure heavy strain and revert to their original shape.
- Fiber-reinforced plastic wrap — made from a variety of polymers — can be wrapped around columns and provide up to 38% added strength and ductility.
Engineers are also turning to sustainable building materials to help reinforce buildings. The sticky yet rigid fibers of mussels and the strength-to-size ratio of spider silk have promising capabilities in creating structures. Bamboo and 3D printed materials can also function as lightweight, interlocking structures with limitless forms that can potentially provide even greater resistance for buildings.
Earthquake-Proof Buildings FAQ
Buildings and earthquakes don’t seem to be a likely pair. Even if you understand the methods used to create an earthquake-proof building, you may have further questions.
Let’s review some frequently asked questions about earthquake-resistant buildings.
What Is the Safest Type of Building for an Earthquake?
According to Exploratorium, a taller structure is safer than a stiffer, shorter building. Flexibility is essential during the shaking associated with an earthquake, and often, the taller the building, the more flexible it is. In fact, engineers must design shorter buildings in earthquake-prone areas to withstand even greater forces than those of a taller building.
Of course, it’s important to account for the materials that are used in the building to determine how well it can withstand earthquakes. Timber, steel and reinforced concrete are the most popular materials used in earthquake-proof buildings.
Can US Buildings Withstand Earthquakes?
The United States is a large land mass and is only prone to earthquakes in certain regions. Instead of constructing every building in the United States to be earthquake-proof, builders often design each structure based on the location’s seismic risks.
For example, a building in San Francisco, California (which sits upon the San Andreas Fault) will have to withstand much larger earthquakes than another building in Miami, Florida, where earthquakes are small and infrequent.
What Are Some Examples of Earthquake-Proof Buildings?
There are earthquake-proof buildings all over the world. Some of these incredible buildings are massive skyscrapers that tower over their city’s skyline, and others are shorter buildings such as airports, arenas and state capitol buildings in earthquake-prone areas.
Here are 10 earthquake-proof buildings across the world:
- Taipei 101 — Taipei, Taiwan
- The Transamerica Pyramid — San Francisco, California
- New Wilshire Grand Center — Los Angeles, California
- Sabiha Gökçen International Airport — Istanbul, Turkey
- Philippine Arena — Santa Maria, Philippines
- Utah State Capitol Building — Salt Lake City, Utah
- Burj Khalifa Bin Zayed — Dubai, United Arab Emirates
- The Yokohama Landmark Tower — Yokohama, Japan
- U.S. Bank Tower — Los Angeles, California
- One Rincon Hill South Tower — San Francisco, California
Great Construction Starts With Great Equipment
Over the years, engineers and scientists have devised multiple techniques to create effective earthquake-proof buildings. However, as advanced as technology and materials are today, it is not always possible for buildings to completely withstand powerful earthquakes unscathed. Still, if a building can avoid collapse and save lives and communities, we can consider that a great success.
No matter what kind of construction project you’re starting, BigRentz has all the heavy equipment you need to ensure you get the job done. From large commercial construction to residential projects, rental construction equipment is available for every job in all 50 states. From materials handling to earthmoving machines, BigRentz has it all.
Check out everything we have to cover by browsing through our available equipment rentals today!
Sources:
How Stuff Works 1, 2 | REIDsteel | Rishabh Engineering | Seeker | Futurism | VIATechnik | Interesting Engineering | Architizer | kcFED | National Geographic
