EVOLUTION OF THE NON-STRUCTURAL SEISMIC INTERNATIONAL BUILDING CODES
Posted on Thu, Mar 12, 2009 @ 01:10 PM
How Does It Affect You?
The vulnerability of non structural components during earthquakes and other natural disasters have been demonstrated and evaluated over time. Perhaps one of the best examples of that vulnerability is California's Northridge Earthquake in January of 1994. With a 6.7 magnitude and the highest ground acceleration ever recorded in an urban North America area [1], California experienced over twenty billion dollars in capital losses, eleven billion of which was attributed directly to government and commercial building damage [1].
Of the damaged commercial buildings, eleven were hospitals with both structural and non structural damage. These facilities were deemed either completely or partially unusable [1]. Not only were they unable to serve the 1600 people who needed hospitalization as a result of the quake [2], they had to transfer existing patients to other facilities, increasing the burden on nearby hospitals.
At the time of the Northridge earthquake, non-structural hazards (notably the collapse of suspended ceilings and lighting systems) were identified as a greater safety threat than even structural weaknesses [2]. Officials estimated that the cost of retrofitting these systems alone would exceed $297 million [2].Damage to these types of critical facilities led to the development of more stringent building codes throughout the US.
In the early 1900's there were three separate non-profit organizations dedicated to developing model construction codes used in the United States. These organizations came together to form one critically needed uniform model construction Code-The International Codes of 2000, 2003 and 2006 [3]. These International Codes have now been adopted at the state or local levels in all 50 states[3].
The International Building Code states [5]:
The code also states that if you are a manufacturer, equipment supplier, design engineer, specifying engineer and/or building owner you are to be held liable for the construction of these buildings. As important as our codes are, it is the professional commitment and capabilities of design and build professionals and compliance officials that ensures code requirements are met [3]. The government supports the importance of the International Building Codes by recognizing communities that effectively institutionalize natural disaster strategies in their building code adoption and enforcement by making disaster grants available.
Resources:
1. "1994 Northridge earthquake." Wikipedia, The Free Encyclopedia. 16 February 2009. 16 February 2009.
2. "Preparing for the "Big One" --Saving Lives Through Earthquake Mitigation in Los Angeles, CA." Hud User Publications. 31 March 2005. 16 February 2009 3. "Climate Benefits of Improved Building Energy Efficiency," International Code Council. 17 July 2008. 16 February 2009.
4. "OSHPD Code Application Notice 2-1613A.1." State of CA Office of Statewide Health Planning and Development. 31 October 2008. 16 February 2009.
5. "Minimum Design Loads for Buildings and Other Structures." The United States of America. ASCE Publications Division, 2006.