All You Need to Know About Earthquake-Resistant Foundation

What Is an Anti-Earthquake House Base?

Simply speaking, an earthquake-proof foundation is the type of a house foundation that can withstand seismic waves. Such foundations are used for houses that sit on soft or filled-in soil mostly. In this case, the building is more prone to damage than a house built on firm and solid ground and may fail in an earthquake regardless of the engineering techniques used.

This is why engineers have created different ways of improving the building-foundation system to enable it to respond to seismic waves. Some of the most commonly used ones include:

• Tying the foundation to the building, which makes the whole structure move as a unit.
• Base isolation involves floating a building above its foundation. This method uses a system of bearings, springs, or padded cylinders.
• Active mass damping. It uses a heavy mass mounted to the top of a building and connected to viscous dampers that work like shock absorbers.

If you are planning to build a house in an area with soft soil and high seismic activity, you should know what anti-earthquake options are available and how they work. But first, it is essential to realize how earthquakes affect our houses in general.

How Does Earthquake Impact Buildings?

When an earthquake occurs, shockwaves are sent and spread throughout the ground in short rapid intervals that extend in all directions. However, most buildings are not ready for this kind of stress! The majority of buildings (both residential and non-residential) are generally created and constructed to handle vertical forces from their weight and gravity. But they cannot traditionally handle side-to-side forces that are emitted by earthquakes.

When such horizontal movements occur, they lead to the vibration of walls, floors, columns, beams, and the connectors that hold all of them together. And even if the earthquake is not strong or doesn’t last long, the difference in movement between the bottom and top of the building produces extreme stress. As a result, the supporting frame ruptures, and the entire structure collapses eventually.

Among the typical kinds of damage caused by earthquakes, there are:

• Cracked walls
• Buildings being knocked from their foundations
• Walls deformation
• Dissipation of a building
• Building damping
• Building oscillation

This is why, as a homeowner, you should be aware of how to make your building resistant to seismic activity in your region. This way, you will bring down the possibility of the potential damage an earthquake may cause and make your home less prone to destruction. 

How to Make a Building Earthquake-Proof

To design an earthquake-proof building, you will need the help of professional engineers that have experience in this field. They will estimate all the risks and work to reinforce the whole structure and counteract a potential earthquake’s forces. Here are some methods that are typically used to help buildings withstand earthquakes.

Start With Creating a Flexible Foundation

Buildings get ruined after earthquakes due to rigid foundations that can’t respond to earth vibrations appropriately. This is why one way to resist ground forces is to lift the foundation of a building above the ground. This is typically made by using a method called base isolation. 

This method is specifically popular when a house is at the beginning of the construction stage. In this case, a building is constructed on top of flexible pads made of steel, rubber, and lead. When the base moves during an earthquake, the isolators vibrate while the structure remains steady. This method helps to absorb seismic waves more effectively. As a result, they can’t be spread through the building.

Use Counter Forces to Prevent Damping

This method is somewhat similar to the one that shock absorbers use in cars. Engineers also use a version of shock absorbers to make buildings more earthquake-resistant. 

Like shock absorbers used in cars, the construction ones also reduce the magnitude of shock waves and help reduce the pressure an earthquake makes on the building. This is accomplished in two ways: vibrational control devices and pendulum power.

• Vibration control devices include dampers placed at each level of a building between columns and beams. During an earthquake, the vibrational energy is transferred into the dampers, dissipating the force of the vibrations.
• Pendulum power is primarily used in skyscrapers. It uses a large ball from steel cables connected to a hydraulic system at the top of the building. When the building begins to sway, the ball moves in the opposite direction, thus stabilizing the building.

Make a Shield to Protect a Building from Earthquake Vibrations

This method uses a so-called “seismic cloak.” This “cloak” involves creating a protective barrier of 100 concentric rings made of plastic and concrete. These rings are buried at least three feet beneath the foundation of the building.

When an earthquake occurs and seismic waves enter the rings, ease of travel makes these waves move through to the outer rings. As a result, they are essentially transferred away from the building and dissipated into the ground.

Make Sure to Reinforce the Building’s Structure

To withstand collapse during earthquakes, buildings must be able to redistribute forces that travel through them during seismic activity. In most cases, engineers use shear walls, cross braces, diaphragms, and movement-resisting frames for reinforcing a building.

Shear walls, for example, can help transfer earthquake forces and seismic waves. They are made of multiple panels, helping a building keep its shape during swaying. 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.

Diaphragms are another part of a house reinforcement system. They consist of the building’s floors, roof, and decks placed over them and help remove tension from the floor. As a result, seismic forces are pushed to the building’s vertical structures.

Finally, there are movement-resisting frames. These ones provide additional flexibility to a building. The movement-resisting frames are placed among a building’s joints, allowing columns and beams to bend while the joints remain rigid. Thus, the building can resist the larger forces of an earthquake.

Now you know not only how earthquakes may affect a house, but you also know what methods are used for reinforcing a building to make it more seismic-proof. This will help you understand how anti-earthquake methods work, which is crucially important if you are building a house for yourself in an area with high seismic activity.

What Materials Are Used For Making a Building Earthquake-Resistant

As you already know, there are different methods used by engineers for reinforcing a building and making it seismic-proof. The most common methods include shock absorbers, pendulums, and anti-earthquake “cloaks.”

On the one hand, using these tools may help you keep your home safe and not collapse during an earthquake. However, the materials you choose for constructing a building are equally responsible for its seismic stability!

Steel and Wood

To be able to resist stress and vibration that occur during an earthquake, the material must have high ductility, which means the ability to undergo large deformations and tension that occur during even the weakest seismic activity. 

In this regard, structural steel is a very beneficial material. This material comes in a variety of shapes and allows buildings to bend without breaking. This is why modern buildings are often constructed with structural steel. Wood is another material that can be helpful thanks to its surprising properties, such as high strength relative to its lightweight structure.

Innovative Materials

Although wood and structural steel are popular materials for constructing seismic-proof buildings, scientists and engineers have developed new building materials that possess even more excellent shape retention. For example, there are innovative shape memory alloys. They have the ability to both endure the heavy strain and revert to their original shape. In addition, they also include fiber-reinforced plastic wrap made from a variety of polymers. This extra component can be wrapped around columns, providing up to 38% added strength and ductility!

Of course, engineers don’t forget about the natural elements to use for reinforcing buildings. For example, they consider the sticky yet rigid fibers of mussels and use qualities of a spider web (like its strength) in creating seismic-proof structures. 

Also, bamboo and 3D printed materials are taken into consideration thanks to their lightweight, interlocking structures and limitless forms. These materials inspired by nature can potentially provide even more excellent resistance for buildings.

Now you know more about earthquake-proof foundations. You learned what type of foundation it is, how it works, and what benefits it has for a building. For example, compared to a regular rigid foundation, its more flexible seismic-resistant alternative will help a building to remain stable and avoid being damaged during earthquakes. Buildings with seismic-proof foundations often avoid such negative earthquake impacts as broken walls, deformations, dissipation, and others.

We also told you how earthquakes might affect your home and what types of reinforcing methods engineers use to keep buildings safe and sound. Finally, you learned what materials are used for this purpose.