Are Modern Homes Earthquake Proof? Can it survive disasters like fires and hurricanes? Interesting questions as we have seen many disasters with buildings tumbling to the ground.
The fact remains that any building, no matter where it stands, from mountains, forests, city center, to a beachfront, is prone to disasters. However, if you want the short answer for earthquakes, yes, the modern home is earthquake-resistant. Yes, we can see that frown on your face, thinking, “Yeah, right!” Let’s find out why we are saying this.
The truth is that over decades there has been an introduction of new designs and building materials incorporated by engineers. These buildings include earthquake-proof houses and building models. A fact is that it all comes down to the importance of earthquake-resistant structures. To learn more about how these buildings are designed today, keep reading.
Importance of Earthquake Resistant Structures
Before we look at how earthquake-resistant these buildings are designed, it helps to understand how a significant tremor can impact any artificial structure. When tremors occur, shockwaves move throughout the ground. It can start at short intervals in different directions.
While most buildings can handle various vertical forces from weight to gravity, they cannot take a side-to-side impact produced by quakes. The floors, columns, beams, connectors, and walls vibrate from the horizontal load and place loads of stress on the support frame causing it to rupture and collapse. So how does an engineer build such a house?
For designing such a building, the structure needs to be reinforced to counteract the quake’s force. Why? An earthquake releases loads of energy, pushing constructions in all directions; therefore, the building must push in the opposite direction. Here are some of the most crucial design features to help make a building stand after a quake:
The Frame and Load Bearing Wall Structure
The house design comprises diaphragms making up the central part of the structure. These consist of the roof and floors. Engineers place decks over them to remove the tension from below as the force pushes into the vertical form of the house.
So to enable a collapse, it needs to redistribute that force to travel throughout the building. For this reason, engineers use different elements making up the central part of the building to reinforce it. For example, shear walls play a crucial role in transferring the quake’s force in the frame structure.
The walls are made up of panels helping the building to retain its shape. In addition, in the walls, you have diagonal cross braces made of steel to support the compression helping to counteract the pressure pushing the force back to the foundation. Another crucial part is the cross bracing discussed here.
Importance of Cross Bracing
Great, what does that mean? The cross-bracing system in an earthquake-resistant house model has diagonal supports. These bracing systems intersect when a quake starts. Engineers use different braces, beams, and columns to transfer the load from the seismic activity back to the ground.
The Significance of the Trusses
When you look at most modern buildings built today, they need durable trusses to make them earthquake resistant. The trusses add strength where the different diaphragms are weak. You will notice that they are primarily diagonal structures fitting into rectangular angles for the framework. Lastly, the moment-resisting frames are just as important.
These comprise an assembly of beams with columns. Engineers use flexible shafts rigidly connected to the columns. The frame provides resistance with lateral forces through the columns while the beam’s connectors and joints remain rigid.
The Importance of Seismic Retrofitting
As most new modern homes are earthquake-resistant houses, this next part is crucial for all older homeowners. What is seismic retrofitting? Seismic retrofitting is a procedure to ensure that the structure of your building is safe if ever an earthquake does strikes. According to FEMA Quake, Smart Program getting seismic refitting done is vital. It reduces the risk of a quake, helping to prevent displacement from the foundation, improving your home’s safety levels and stability. Furthermore, it helps provide:
As seen in earthquake-resistant buildings, it helps protect you and your loved ones in a quake. Have you ever been in an earthquake? Maybe you have, perhaps not. But your home shakes, and things start falling around you, making you terrified. Seismic retrofitting helps prevent your house from collapsing and passes by without causing too much harm, allowing you to get out safely.
Protects Your Investment
Furthermore, as the structure remains standing while you exit, it might need repair and needs no demolishing and replacing. Therefore, your investment is protected and will not cost you a lot compared to having it rebuilt.
Reduce Property Damage
An earthquake retrofit will prevent displacement of the structure’s concrete foundation. In turn, it makes your home or office building safer with the likeliness of suffering minor damages. In addition, having a foundation bolting done costs less than having your entire home rebuilt. The majority of repairs will only be cosmetic, from cracks, drywalls to the plaster.
Provides You With an Escape Route
When you live in an earthquake-resistant home retrofitted for seismic activity, it is more robust. Therefore, it provides you with a safe exit while shaking. Furthermore, it reduces the risk of injury or even death.
Helps Ease Anxiety
If you have ever been in an earthquake, you know how anxious you can get not thinking straight as you need to find a safe exit. Seismic retrofit gives you peace of mind to get out as soon as possible, even if your house is shaking. Even after the quake, your anxiety is lessened. As you know, your home’s safety increased, and it can withstand the devastation of the earthquake. Great now that you understand why the above is so important to keep your property protected. How do architects and engineers design a modern home to make it earthquake-proof?
How Is Earthquake Proof Houses Designed
It all comes down to the foundation and material used to make it resistant to sideway loads to earthquake-proof buildings. So what does this mean? First, it means that the building needs to be lighter with fewer loads. For example, if the weight is higher, the roof needs to have a lightweight material structure—the lighter the material, the better the home. The same applies to sideway resistance as the walls need to move in both directions equally. So let’s look a little deeper at the best shape for earthquake-proof buildings and the material.
Using Earthquake-Resistant Building Materials
While using pendulums, shock absorbers, and invisible cloaks help to dispel the force. In addition, the materials play an essential part in providing stability. Therefore, choosing a building material that can resist stress and vibration needs high ductility. Okay, your eyebrows are lifting again.
All it means is that it needs to undergo large deformation and tension. Your modern homes and buildings are mainly constructed of steel in different sizes. Using steel allows the construction to bend, but it does not break. While using wood, surprisingly enough, it is also a malleable material that can withstand high strength and is a lightweight structure.
Other building materials include:
- Shape memory alloys that can endure heavy strain while reverting to their original shape.
- A fiber-reinforced plastic wrap made from polymers around columns can also provide up to 38% more elasticity and strength.
Even natural elements like rigid muscle fibers or the strength-ratio of spider silk are promising to create safe structures using bamboo and 3D printed materials in the design. These structures interlock with other forms to provide resistance for a building against earthquakes.
The Fitting Foundation
Here engineers use base isolation involving floating the building above the foundation using:
- Systems of bearings
- Padded cylinders
The engineers use different types of bearing pad designs. Still, they can also use lead-rubber bearings with a solid lead core wrapped with layers of rubber and steel. What the lead material does is make the bearing stiff and more robust in the vertical direction.
While the rubber/steel bands make it flexible to move horizontally, these bearings attach to the foundation and building with steel plates. So when a quake hits, the foundation moves without the structure moving above it, leading to minor deformation or damage.
The Use of Seismic Dampers
Furthermore, engineers use dampeners similar to shock absorbers in vehicles in an earthquake-proof house model. These can be using vibrational control devices or pendulum dampers. Vibrational control dampers are places at each level of the construction between the column and beam.
The devices comprise piston heads with a cylinder filled with silicone oil. When tremors occur, the vibration energy is transferred into the piston that pushes the oil and transforms to heat. Then, the heat dissipates the force of the vibrations.
The pendulum power is mainly used on skyscrapers using a large ball with steel cables comprising hydraulics placed at the top of the structure. The building moves in the opposite direction to counteract the tremor to stabilize the construction.
To make your home earthquake-proof, engineers use horizontal bands. The bands comprise a lintel band, a plinth band, and a roof band. These bands hold a building as a single unit tying the walls together. The most important one is the lintel used in most buildings. While for a pitched or sloped roof, they use a gable band. No band is required for a flat concrete or brick roof as the slabs work as a band.
Regarding structural reinforcement, we already mentioned base isolation using shock absorbent material in the foundation and columns. The Los Angeles City Hall and the Los Angeles Cathedral are examples of buildings seismic retrofitted using these techniques. In addition, these buildings have “X” braces to transfer the force through the trusses.
While other engineers renovating older homes and apartments provides them with supporting beams called shear walls. The walls accept the energy from the quake to prevent significant damage. Furthermore, they apply shock-crete by reinforcing the existing walls with new steel rods and concrete. Finally, the substance engineers spray the concrete over the rebar comprising steel inside to support the wall.
Are Modern Homes Earthquake Proof?
The answer, as you can see, is yes. Earlier in our article, we said that we would look at the best shape for an earthquake-proof building but did not provide you with the answer. According to the University of British Columbia, the dome is the best shape to resist earthquakes.
When experimenting using a shake table, the dome outperformed most building structures. But the practicality is that these type of buildings take up loads of space and is not easy to utilize inside. Check out this excellent video of a shake table test.
So, do you want to make sure your home is quake-proof? As mentioned above, we recommend having a seismic retrofit done using resistant materials, dampeners and ensure the foundation is flexible.