A schoolbag sits by the remains of a student was killed when a school collapsed in the earthquake-hit Hanwang town of Mianzhu, Sichuan province, May 15, 2008.
REUTERS/Stringer
Fouad Bendimerad, chairman of the board of the Earthquakes and Megacities Initiative, a California-based professional engineer in California who specialises in earthquakes and disaster risk management, describes how buildings can resist earthquakes.Q: Do we have the knowledge to stop buildings collapsing and killing people?
A: We have the knowledge and the technology. In fact, we have had it for more than three decades. But there are two fundamental problems:
1. It is not sufficiently disseminated and applied in day-to-day practice. Most engineers, architects, planners, and builders are not adequately trained in the basic earthquake engineering practice.
2. It is not enforced.
Most countries have seismic codes that are adequate, but these codes are not enforced, because authorities are often not adequately trained to implement them. As a result, buildings collapse and people are killed.
What we are seeing in every urban earthquake is a result of avoidable errors. In earthquake-prone regions, buildings can be designed and be built to sway and crack but not collapse. There may be a need to repair them after an earthquake, but they will not collapse.
Q: Why did so many buildings collapse in China?
A: What happened in China could have happened in any other urban earthquake region.
We must integrate disaster risk reduction considerations in urban planning. We have been advocating for years to introduce training programs for construction professionals, engineers, architects, urban planners, builders and field workers, but the message is lost in the midst of all the noise!
We cannot provide safe urban environments by raising awareness alone. We must also build the competency of the institutions and of the professionals who plan, build, and manage cities. It is much harder to do. But it needs to be done soon.
Q: Is it possible to resist a 7.9 magnitude earthquake anyway?
A: A magnitude 7.9 earthquake is an exceptionally powerful earthquake that would subject buildings to tremendous pressure. Globally, we have little experience in dealing with such big devastating earthquakes in urban areas.
Nonetheless, earthquake engineering knowledge has advanced significantly in the last two decades. Seismologists can provide reasonable estimates of hazard impacts to enable the design of buildings to a required level hazard resistance.
This is the first step because we know that areas which have experienced large earthquakes in the past will experience them in the future.
Seismologists can also provide a projected level of earthquake impacts which could ensure that buildings are not inappropriately designed to withstand certain hazard impacts.
With this information, engineers can design to resist projected hazard impacts. For such large earthquakes, the aim is simply to prevent the building from collapse and to protect the safety of the occupants. The damage could be substantial, and the building may need extensive repairs, if not complete reconstruction.
With proper technology and adequate knowledge we can construct buildings to resist even the largest earthquakes without collapse.
Q: Do you think the lack of investment in building earthquake resistant buildings is mainly due to financial reasons?
A: I don't think that is the case because building earthquake resistant structures makes good economic sense. There is a premium in the cost - 3 to 5 percent for typical buildings - but that additional cost is more than recovered in the reduction of life-cycle costs, protecting the property and its occupants, and in avoiding heavy repairs after an earthquake.
The main impediment is the lack of strict regulation for building code enforcement, the lack of clear accountability, and the lack of competency in earthquake construction among practitioners at all levels.
There is also a resistance from both the public and private sector to invest in hazard and vulnerability studies. Many institutions are short-sighted and prefer to ignore the problem. It is easier to think that it may not happen during our lifetime.
Q: Do you think that critical infrastructure such like schools, hospitals and chemical plants should be better protected in any quake-prone region?
A: Absolutely. These are high-risk facilities that are essential for well-being of communities. So are lifeline systems such as water, sanitation and power. Actually, building codes recognise the need for providing better protection to these facilities.
Again, the knowledge is there but the practice and the regulations lag behind.
This interview was done by Brigitte Leoni, media officer for the U.N. International Strategy for Disaster Reduction secretariat.
Residents search for their family at a collapsed building after an earthquake in Dujiangyan, Sichuan province May 13, 2008. China said on Tuesday an earthquake centred in the southwest province of ...
