Earthquake Preparedness: The Importance of Building Codes
Are you prepared for an earthquake? On Thursday, October 16, 2014, FEMA and FEMA National Earthquake Hazards Reductions Program (NEHRP) supported the Great ShakeOut Earthquake Drill. Millions of people registered to participate in the drill and “drop, cover, and hold on” demonstrating what they should do in the event of an earthquake.
In addition to personal preparedness, communities need to be prepared. What steps can your community take to prepare before an earthquake? One way to improve safety is by adopting and enforcing building code guidelines – well before an earthquake shakes your community.
Building Codes are sets of regulations governing the design, construction, alteration, and maintenance of structures. These codes specify the minimum requirements to safeguard the health, safety, and welfare of building occupants. Most states and local jurisdictions adopt model building codes maintained by the International Code Council (ICC). The ICC updates codes every three years. According to FEMA, adoption of seismic provisions to codes is inconsistent, even in states more susceptible to earthquake activity. Unless a community has adopted the most current building codes, including seismic provisions, new structures will probably not provide the current minimum level of protection from earthquake hazards.
Code enforcement is, for the most part, the responsibility of local government building officials who review design plans, inspect construction work, and issue building and occupancy permits. Without adequate code enforcement, the safety of citizens may be at risk. “A properly functioning building department will ensure that structures are designed and built to meet all building codes, including seismic codes, to protect the welfare of the community’s citizens,” stated Paul Hancher, Director of Building Department Services at the Institute for Building Technology and Safety (IBTS).
Additionally, unless existing buildings are significantly renovated, altered, or there is a change in use, the buildings will only meet the code requirements in place when built. FEMA asserts that older, existing buildings are the single largest contributor to seismic risk in the United States today.
High-risk existing buildings can be made safer through seismic retrofitting. FEMA outlines the following steps for this process:
- Survey the building using Rapid Visual Screening of Buildings for Potential Seismic Hazards (FEMA 154)
- Evaluate the building using Seismic Evaluation of Existing Buildings (ASCE/SEI 31-03)
- If evaluation suggests that retrofitting is necessary, this should be done using Seismic Rehabilitation of Existing Buildings (ASCE/SEI 41-06)
Retrofitting must include steps to better protect non-structural components, such as non-load-bearing walls and suspended ceilings. Seismic retrofitting of vulnerable structures is critical to reducing risk. Communities that take the necessary steps to retrofit structures can recover from earthquakes more rapidly than communities with older, more vulnerable structures.
The U.S. Geological Survey (USGS) asserts that the greatest risk in an earthquake is the severity of the shaking it causes to manmade and natural structures, as well as the contents within the buildings that may fail or fall. Earthquakes are not confined to a limited geographic area; at least 39 states are considered at moderate to very high earthquake risk. With nearly 80% of the US at risk for damage resulting from earthquakes, communities should ensure they are properly prepared. According to FEMA, the most important factor in reducing earthquake-related risks is the adoption and enforcement of up-to-date building codes.