Last June 15th, a 6.3 magnitude earthquake shook the lands of Calatagan, Batangas that awakened a large portion of the country in a sudden jolt. According to a report by Rappler, the powerful shake has a depth of 1.3 kilometers. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) warned the public of aftershocks reaching up to Intensity IV in Metro Manila and nearby cities.
In the event of a major earthquake, not only the lives of people are at risk, but the safety and strength of buildings and establishements as well. Earthquakes are nature’s way of displaying its formidable force, with the potential to wreak havoc in communities, leaving behind a trail of destruction of structures. As the Philippines sit within the Pacific Ring of Fire, it is prone to experiencing seismic activities with varying magnitudes and intensities that may cause destruction to properties.
As the Philippines continue to face the threat of earthquakes, safeguarding homes against these tremors becomes an essential priority for homeowners. Which then leads us to the question, “Is my House Earthquake Resilient?”
In this article, we will take a look at the features of earthquake resistant buildings as well as how you can integrate them into your home.
How Can I earthquake-proof my House in the Philippines?
Build a flexible foundation
BigRentz shares some insights on how earthquake resistant structures are designed. And one of the crucial components is the flexible foundation of the establishment.
When the plates beneath the Earth move, they send tremors that may cause a building or establishment to crumble down. That’s why a sound and flexible foundation is extremely crucial. Big Rentz states that one of the ways to withstand earthquakes is to ‘lift the building’s foundation above the earth through a method called base isolation.’
The building is constructed on top of flexible pads that are usually made of steel, rubber, and lead. These systems of padded cylinders and ball bearings serve as shock absorbers that absorb seismic waves when an earthquake occurs.
Taking this context in home construction, Civil + Structural Engineer suggests to ‘place a solid foundation slab made of reinforced concrete and crisscrossing strips atop an intermediate cushion of sand.’ A house built with a foundation made with reinforced concrete slabs can withstand the shaking during earthquakes.
Not to forget, earthquake proof buildings should be built on a stable and strong soil.
Reinforce the building’s structure
To prevent the collapse of the property, the force of the earthquake should be evenly distributed. There are several essential elements to achieve this:
Diaphragms – The best examples of diaphragms are floors and roofs. They are beams built with their own decks that distribute the earthquake force to the vertical elements of the building, minimizing the earthquake damage.
Shear walls – Shear walls prevent the swaying of the building by stiffening the structure’s frame. These panels are usually supported by diagonal cross braces made of steel.
Moment-resisting frames – When it comes to flexibility, the moment-resisting frames get the job done. Optimum Seismic describes these as ‘an assembly of beams and columns in which those beams are flexible, but are rigidly connected to the columns.’ The way it is constructed allows the beams to sway while the joint remains steady and rigid.
Trusses – Trusses are diagonal structures that give additional strength to the diaphragm’s weak points.
Cross-bracing – This diagonal intersecting system aims to revert the seismic waves back to the ground.
Shore up your windows
Building earthquake resistant structures also takes windows into consideration, too. Glass windows may shatter that can cause injury to your family. That’s why it’s important to shore up your windows to hold the glass in place in case it shatters.
Install light roofing
It is a rule of thumb that building earthquake proof homes means installing light roofing. Check out our article about choosing the right roofing for your home in the Philippines.
Integrate innovative materials
When building earthquake proof houses, the quality and type of materials should also be taken into consideration aside from the construction. Reinforced concrete and wood are some of the favored earthquake resistant materials used in building houses within an earthquake zone as they remain intact under strong forces of seismic activity.
Big Rentz further states that innovative materials such as memory alloy are taken into consideration as they can also withstand seismic activity while maintaining their shape. A fiber-reinforced plastic made up of a variety of polymers provides 38% added strength and stability when wrapped around a column.
Moreover, a research conducted by Indian Institute of Technology Roorkee shows that thermocol– Expanded Polystyrene (EPS) can be used as a material to build earthquake resistant homes. Aside from that, their test revealed that this unconventional material also provides excellent thermal insulation and performs well at energy conservation in construction.
In addition, scientists and engineers are also tapping into nature to counter the force of nature itself through bamboo, mussels, and spider silk.
If your house is made-up of materials like stucco or brick that are usually less earthquake resistant, you may have to conduct a seismic retrofitting to reinforce your house and withstand earthquake forces.
What is Seismic Retrofitting?
The concept of earthquake-proofing, also known as seismic retrofitting, has emerged as a critical approach to mitigating the devastating impacts of seismic events on residential structures.
Earthquake-proofing entails implementing structural modifications and engineering strategies that enhance a building’s ability to withstand the forces unleashed during an earthquake. From reinforcing foundations and strengthening load-bearing walls to securing fixtures and utilities, the process involves a comprehensive evaluation and implementation of measures tailored to the specific needs of each home.
Check your house’s earthquake resiliency through the Phivolcs app
The Philippine Institute of Volcanology and Seismology (Phivolcs) has launched a self-check app that will aid homeowners in evaluating the resiliency and structural integrity of their house against natural disasters like earthquakes.
The app ‘How Safe Is My House?’ answer 12-point questions which are as follows:
1. Who built or designed my house?
2. How old is my house?
3. Has my house been damaged by past earthquakes or disasters?
4. What is the shape of my house?
5. Has my house been extended or expanded?
6. Are the external walls of my house 6inch (150mm) thick CHB?
7. Are steel bars of standard size and spacing used in walls?
8. Are there unsupported walls more than 3 meters wide?
9. What is the gable of my house made of?
10. What is the foundation of my house?
11. What is the soil condition under my house?
12. What is the overall condition of the house?
The app also has a website version that can be accessed here.
Earthquakes can have devastating consequences, causing loss of life, destruction of property, and long-term economic and social impacts. However, through careful planning, engineering expertise, and the incorporation of innovative technologies, it is possible to construct homes that can withstand the unpredictable shake with minimal damage.
By implementing seismic design principles, such as reinforced foundations, flexible building materials, and strategic bracing systems, homeowners can significantly increase the structural integrity of their homes. These measures help dissipate the energy generated during an earthquake and prevent it from causing catastrophic damage. Additionally, advanced construction techniques and materials, such as base isolation and damping systems, can further enhance the resilience of buildings against seismic events.
An earthquake-resilient home not only protects the lives of its occupants but also helps communities recover more swiftly after a disaster. By minimizing structural damage, the need for extensive repairs or even reconstruction can be reduced, saving valuable time and resources. This is particularly crucial in regions prone to frequent seismic activity, where the ability to bounce back quickly is essential for social and economic stability.
Building an earthquake-resistant home is a proactive and necessary measure to protect lives, preserve property, and promote the overall resilience of communities. It is a collective effort that requires collaboration between various stakeholders to create a safer and more sustainable built environment. By investing in earthquake-resistant housing, we can mitigate the impacts of earthquakes and ensure a safer future for generations to come.