GENEVA, 10 October 2007. In 2007, the UN Sasakawa Award for Disaster Risk Reduction Jury selected Tony Gibbs, a national of Grenada and Barbados currently working with the Pan American Health Organization (World Health Organization in the Americas) on hospital safety, as one of its two Sasakawa Award Laureates. A pioneer in promoting safe architectural designs against natural hazards, he has made a significant contribution to hazard awareness and disaster risk reduction by designing building structures resilient to earthquake and wind forces.
Why did you start working in this field of hospital safety?
From the start of my professional career I worked with companies and engineers who were concerned about designing structures to resist the natural hazards of hurricanes and earthquakes. So I took it for granted that I should pay attention to these matters. In particular, the Pan American Health Organization (World Health Organization in the Americas) gave me the opportunity, starting in 1985, to work on vulnerability analyses and retrofitting of existing healthcare buildings, and on design issues for new buildings.
Is hospital safety an urgent matter to be addressed?
The question of the resilience of hospitals to hurricanes (and earthquakes) came into sharper focus for me when, in a series of natural hazard events in the Caribbean during the past 35 years, hospitals suffered at least as much damage as other less important facilities. These events were hurricanes in 1979 (Dominica), 1988 (Jamaica), 1989 (Montserrat), 1995 (Antigua), 1998 (St Kitts), 2004 (Grenada) and earthquakes in 1973 (Antigua), 1997 (Cariaco, Venezuela), 2003 (Dominican Republic), 2004 (Dominica). Some of these buildings were relatively new. Clearly, a fresh approach to designing, building and maintaining healthcare facilities is required. Part of this fresh approach must be the routine independent checking of designs and quality assurance procedures during construction.
What are your main achievements in this area?
I consider that my main achievement in this area is to convince others (owners, designers and builders) that success is possible, that disaster is not "natural" and that money (or the lack thereof) is not the problem. Indeed, the most expensive hospital is the one that fails. Paradoxically, the poorer the society, the more resilient the hospital should be. Poor societies cannot afford failures. There must also be the recognition that in small, island countries there are usually single referral hospitals. If the one hospital is destroyed or damaged so that it cannot function effectively when it is most needed, that becomes part of the problem and not part of the solution. That is a disaster. An important part of my role is the empowerment of those who are the owners, custodians, managers and procurement officers of healthcare facilities. In fulfillment of that role I write and lecture to those people about how they should brief architects and engineers, what they should expect from architects and engineers and how to monitor the work of architects and engineers.
How do you make hospitals resistant to earthquakes? Could you explain how your designs protect buildings against wind and earthquakes in simple words?
The philosophy of earthquake-resistant design is conventionally different from the philosophy of wind-resistant design. Conventional design against earthquakes aims to protect lives (not buildings) in extreme events. This is unsatisfactory for critical facilities, such as referral hospitals, which are required to function to their optimum immediately following a very damaging earthquake. Conventional earthquake-resistant design aims to absorb the seismic forces through ductility in the structure accompanied by the (hopefully predicted) "failure" of pre-selected elements. This is admittedly a difficult concept to appreciate. This leads to a less than functional hospital. To achieve fully-functional hospitals we should adopt base isolation techniques (isolating the building from the oscillations of the ground) and install mechanical energy-absorbing devices in the superstructure of the building.
The philosophy of design against hurricanes is to achieve complete success (no significant damage to the building) in a severe event. The focus here is usually on the external envelope - external walls, windows, external doors and roof covering. Unfortunately, these components are rarely within the mandate of the structural engineer. In designing these external elements we must concern ourselves not only with wind forces, but also with flying debris.
Is it the same technique?
Designing against multiple hazards is more than doubly difficult when compared with designing against a single hazard, especially when those multiple hazards are wind and earthquake. Many favorable features of wind-resistant design are unfavorable for earthquake-resistant design, and vice versa. Heavy structures resist winds better. Light structures resist earthquakes better. Flexible structures attract greater wind forces. Stiff structures (generally) attract greater earthquake forces. Both hurricanes and earthquakes impose horizontal loads on buildings. Earthquakes also impose significant vertical loads on a building overall. The vertical loading from wind is usually determined by aerodynamic considerations. However, there are many similarities in the effective design and construction of buildings to resist hurricanes and earthquakes: Symmetrical shapes are favorable. Compact shapes are favorable. There must be a realization of the real risk that "design" forces may be exceeded. This is particularly so in the case of earthquakes where, largely for economic reasons, the design force is deliberately determined to be less than that expected during the anticipated life of the building. This leads to a requirement for redundancy in the structure and for "toughness" – the ability to absorb overloads without collapse. Connections are of paramount importance. Each critical element must be firmly connected to the adjacent elements. There is a basic difference in the performance expectations in the event of an earthquake as opposed to a hurricane. A building is expected to survive its "design hurricane" with virtually no damage. Even a catastrophic hurricane should only lead to repairable damage. On the other hand the "design earthquake" is expected to cause (hopefully repairable) damage, and a catastrophic earthquake is likely to lead to a situation where the building cannot be repaired and must be demolished. In such an event, success is measured by the absence of deaths and serious injuries.
How much does it cost to do it?
The answer to the question depends greatly on the design concept. If the concept, shape and configuration of the building faithfully follow the precepts of good earthquake and hurricane resistant design, then the cost is insignificant.
In the case of hurricanes that cost could be about 2%. In the case of earthquakes that cost could be 3.5%. In the case of both hurricanes and earthquakes the combined cost could be as high as 4.5%. These are conservative figures for new buildings. The cost of retrofitting existing buildings could be much higher, especially in the case of earthquakes
Why governments do not do it systematically? What are the challenges and main problems to address the issue?
This is the most difficult question of all to answer. I should be a politician to do so, but I will try. Part of the answer is the erroneous perception that resilient buildings are not affordable. Part of the answer is that earthquakes and hurricanes are low-frequency events in any single location and it is unlikely that severe earthquakes and hurricanes would occur during the 5-year lifetime of a democratically elected government. Part of the answer is that, remarkably, multi-lateral funding agencies are unwilling to impose appropriate technical standards as conditions precedent to disbursement of loans and grants.
Is it also due to a lack of knowledge among engineers and architects?
Certainly, educational programmes in universities fall short of what is required in the fields of earthquake-resistant and wind-resistant design. Then in the "real world" most regulatory agencies are ill equipped to effectively check the designs presented to them for approval. The designers therefore have insufficient incentive to become really proficient in the relatively difficult areas of earthquake-resistant and hurricane-resistant techniques.
Climate change is making the issue more urgent, what needs to be done and what is realistic to do?
Climate change has the potential to increase the frequency and severity of hurricanes. This can be dealt with simply by an "overlay" or additional factor to be applied to the basic wind speed in determining the appropriate design wind speed. The factor would depend on the anticipated life of the building. I say "simply". However there is a difficult part. That is determining the values for the factor. So far this "overlay" does not appear in any known design standard. However, I am working on it.
Your designs have influenced design standards worldwide. How did a small island like the Barbados managed to lead the way? How did you manage to influence the world?
First of all I must say that I work throughout the Caribbean, not only in Barbados. I went to school in four Caribbean countries, starting in my home country of Grenada. I have lived in six Caribbean countries. I have worked professionally in all but one of the Caribbean countries - English, Spanish, French and Dutch speaking. I have had tremendous support regionally and internationally from organizations such as PAHO-WHO, UNDP, the Organization of American States, the Caribbean Development Bank, The Institution of Structural Engineers (UK), my own firm (Consulting Engineers Partnership Ltd) and from Professor Alan Davenport of the University of Western Ontario.
Have you only specialized on hospitals or have you focused on other buildings?
Most of the work during my career was not in connection with hospitals. I started my career as a general civil engineer. Then I gravitated towards structural engineering. Soon after I began concentrating on structures to resist earthquake and wind forces. Now I spend a lot of time in connection with healthcare buildings.
You have said that you will develop a post-graduate course in engineering for building design and damage mitigation for natural hazards. Why is it such a priority and how will the award money be used to support it?
One of the main problems to be solved is how to ensure that hospitals remain fully functional during and immediately following severe hurricanes and earthquakes while considering the usual financial constraints. Dealing with the hurricane hazard requires special attention to be paid to the building envelope in general and to glazed openings in particular. Dealing with the earthquake hazard requires the application of energy absorption devices in superstructures and the application of base isolation.
The construction industry (design engineers, architects and constructors) are generally unfamiliar with these techniques. There is the need to bring these techniques into the mainstream of hospital design and construction. In order to do so, primers (introductory books) are required; focused courses for architects and engineers are required; and oversight on demonstration projects is required. The Award money would be used to seed these activities.