How sure are you that you and your family are safe in your home sweet home in case of an earthquake or hurricane?
The last thing you want for your home sweet home is to become a pile of rubble or a coffin in the making in the event of a disaster, be it a hurricane just like what super typhoon Haiyan (Yolanda) that hit the Visayan region or the dreaded earthquake which damaged most of Bohol just this November 2013.
Last March 2011, a magnitude 9 earthquake triggered gigantic tsunamis and ferocious ground shaking that threatened annihilation of some Japanese cities such as Sendai.
Even the most delicately designed structure like the Fukushima Daiichi nuclear power plant sustained sufficient damage to let the world stand on its feet, raising fears of becoming another statistic like Chernobyl, Kyshtym disaster at Mayak Chemical Combine (MCC) Soviet Union, Tokaimura Nuclear Accident and the rest1.
Note that hazardous facilities such as nuclear power plants are given more rigid design considerations. The objective is, in the event of a disaster, this type of structure should still be standing or that it must sustain minimal or “manageable” damage. Do you ever wonder what would have happened if the nuclear structures were not designed properly? When it toppled to the slightest ground shaking that radioactive particles escaped into the oceans? God, forbid! It would have been monstrous. And it would be a lot more horrific than eating radioactive sushi!
Ground shaking is only the first part. What was left standing after the tremors are threatened to be wiped out by tsunamis of heights similar to that of a two-story building.
Of Tropical Cyclones
Hurricane Katrina is still fresh in the minds of the affected people much like Hurricane Haiyan (Yolanda) that ravaged half of the Philippine archipelago.
With Haiyan having maximum sustained winds of 315 km/h (195 mph) and gusts up to 378 km/h (235 mph)1 who can and who will stand a chance? Aside from the wind, gigantic storm surges reaching up to 5–6 meter (15–19 ft)1 waves from the oceans are hurled with enough inertial momentum to wipe out almost anything left by the wind. The local people described it as a tsunami. Different names but just as deadly.
Even reinforced concrete homes didn’t stand a chance on the pounding winds and waves. What the people thought to be a place of refuge turned out to be a dead end because of the storm surge as what happened to some evacuation centers.
We Stand a Chance
Catastrophes of this magnitude can topple and level almost everything in its path including reinforced concrete homes and much more of houses built with light materials. And with that, you might say that with such intensity of catastrophe, every structure, properly designed or not doesn’t have a chance. You may be right. But what if you only had a minute or two to evacuate and go to safety compared to not having any warning at all?
By law, it is the responsibility and accountability of engineers and architects to design and build habitable and safe structures fit for living. But for emphasis, IT IS YOU AS THE OWNER, who has the responsibility for the safety of yourself and your kids! You may not have the technical expertise of engineers but you have the power to select qualified individuals who will make your space a safe haven and not a coffin in the making.
Being a structural design engineer myself, let me give you some basic background on what to expect for you to be able to have a high degree of confidence to your designers and builders.
Q: If the structural code is followed through in the design process, will my home/building be earthquake and hurricane proof?
A: No. There is no such thing as earthquake-proof and wind-proof structures. Structural codes exist to provide the buildings minimum requirements for structural members such as columns, walls and beams (minimum reinforcement and sizes), which will meet the estimated effects of ground shaking, wind, storm surges or tsunami to the structure.
NO ONE, NOT EVEN ENGINEERS AND MUCH MORE ARCHITECTS CAN PREDICT the magnitude of forces that will be imposed to the structure.
The code was provided to meet ductility requirements for buildings. In layman’s term, to give occupants ample time to escape to safer grounds before it crumbles. Without following the code, the designer or builder, and the home owner (who might be unaware) risk the structure to be brittle in nature – it will suddenly collapse without the possibility of escape.
Q: Engineers and architects, what’s the difference?
A: Architects provide your home with a functional and a pleasing aesthetic home or building. Structural design engineers like us, are concerned with the STRENGTH of your home, making sure that the house/building still stands to provide every occupant ample time to go to safer grounds in the event of disasters if not to become a fortress of refuge. If you want your home to have a 5 Star-like quality of aesthetics and functionality, go to the architect. You want to make sure that you have a structurally sound home? Go to the structural engineer.
One important reminder: don’t exchange safety with beauty. By nature, architects want thinner walls and floors, smaller columns and beam sizes. This is architecturally good because you will have a bigger space but it may incur significant strength loss structurally speaking. So before you oblige to your architects, please prefer your safety first always. Would you prefer a beautiful but unsafe home that will suddenly crumble in a few seconds in the event of a typhoon or earthquake? Or like a tomb that may be beautiful outside but inside resides dead or “walking dead” people?
Q: A local carpenter/foreman tells me that the columns are ridiculously big. He also told me that in his experience, a smaller size would suffice. He then offered me to reduce the size, reinforcing bars and eventually the cost.
First, you cannot hold him responsible legally if something happens. Only civil or structural engineers are allowed to sign structural plans. Second, the houses he built may not have experienced earthquakes yet (lucky for him and the occupants). Third, who knows, he’s doing it wrong in his 20 years of experience? I bet you don’t like to be the proof that he’s wrong for the longest time!
This is not to discount the expertise of experienced builders. However, remember that in life, you get what you pay for. Personally, I don’t like the word may be, especially in the context of “it may be safe.” Safety should be the last thing you should bet.
In addition to the list, you might want to ask your real estate agent, architect, or engineer the following when buying or transacting your dream home/building:
1. Is the house/building designed for earthquake?
2. Who is the designer? Is he or are they in good reputation?
3. What’s the nearest fault in the area?
4. What’s the probability that storm surge and tsunami will reach us? (If the structure is in coastal area)
5. Is it prone to landslide? (If the structure is in a valley, near a cliff, or on top of a mountain, plateau, etc.)
Please consider this as a primer, a heads-up, or an eye-opener that should engage you to be concerned to a red alert status instead of just relying on your architects, engineers, or foreman.
You and your family are worth more than a few thousands of pesos that goes with a properly designed home. What you save now may be your risk tomorrow. Or if we put it in an affirmative type of approach, what you risk today may save you tomorrow. The choice will always be yours.
- A call for integration of earthquake-proof principles (businessmirror.com.ph)
- Everything You Need To Know About Super Typhoon Haiyan (elitedaily.com)