Page 49 - Occupational Health & Safety, May 2017

DISASTER PREPAREDNESS
Building Performance in Earthquakes and the U.S. Resiliency Council’s Rating System
The greatest value of a building rating system is one that meshes with economic decisions.
BY RON MAYES, EVAN REIS, AND ALAN KLEMBCZYK
Maybe it’s the office building where you work. Maybe it’s the multi-story apart- ment complex where you live.
Do you have any idea how it will per- form in the next major earthquake?
The design philosophy of current building codes states that they are intended to minimize risk against major failures and loss of life, not to limit damage, maintain functions, or provide for easy repairs. This often comes as a surprise to many building owners and occupants who believe they are getting an “earth- quake proof” building when they hire a competent structural engineer to design a code-conforming building. Code-designed buildings are designed to avoid collapsing during a major earthquake but aren’t quite up to the task of remaining inhabitable after disaster strikes. In fact, a modern building designed to the current code could be condemned and demol- ished immediately after a large earthquake.
If more building owners, residents, and landlords were aware of the gap between current building code and how performance during earthquakes could be rated and improved upon, things would be different.
Building Performance in Past Earthquakes
As we have painfully learned in many recent disasters ($30B in 1994 Northridge, $170B in 1995 Kobe, $20B in 2011 Christchurch, New Zealand, and $300B in 2011 Eastern Japan earthquakes), the major economic issues relate not only to the direct cost of earthquake damage, but also to the business disruption costs as- sociated with the loss of one or more buildings for sig- nificant periods of time. These include loss of produc- tion or operations, loss of sales or services, and loss of ongoing research and development in some industries (e.g., the biotech industry). These losses translate into major economic issues for a corporation, including loss of revenue¸ loss of market share, and loss of share value. Clearly, these business disruption costs over- whelm any first-cost considerations.
A recent example of the mismatch in public ex- pectations was the performance of a full range of old and modern buildings in the Central Business District of Christchurch, New Zealand, during the February 2011 earthquakes. The New Zealand codes are simi- lar to those used in the United States. Two buildings
Is this the performance you expected?
collapsed, but the others performed as expected by the structural engineering profession in that they provided life safety for the occupants. What was not expected by the public at large was the need to demol- ish 70 percent of the buildings in the CBD due to the damage they had sustained.
The notion that there is a disconnect between the anticipated performance of buildings in a major earthquake and what the public understands or ex- pects is not new. The thought was that if the public could be made more aware of their potential seismic risk, they could be expected to make better-informed decisions on owning and leasing properties, and mar- ket forces would eventually drive the building design, management, and procurement process into more re- silient seismic design.
A building rating system will help owners, tenants, investors, and other stakeholders understand how a building will perform in the next large earthquake. Without it, many owners may be surprised and disap- pointed with how their code-compliant buildings fare. A building rating system that is designed to speak to the population as a whole, in terms that are under- standable and meaningful in their day-to-day deci- sion-making, has the potential to change the game in risk communication and elevate seismic performance considerations into everyday conversations involved in building, buying, or leasing a building.
The U.S. Resiliency Council and
its Building Rating System
The United States Resiliency Council (USRC, www. usrc.org) was launched in November 2015, and its
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MAY 2017 | Occupational Health & Safety 45
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