The Seismic Committee of the Structural Engineers Association of Utah read with interest your article of Sept. 29 on "Hazards of the Wasatch Range." One of our committee's goals is to help create a public awareness of the danger that earthquakes pose here in the state of Utah, particularly along the Wasatch Front. Articles such as this will help in this effort.
As we discussed the article in our committee meeting, we thought it would be helpful to emphasize a couple of our concerns and provide ideas of ways the community can help minimize the losses that will occur from an earthquake.
Older existing buildings pose one of the greatest life safety threats from earthquakes to our communities.
Of particular concern are many of our older K-12 schools. Past earthquakes have shown that the typical construction in these older schools makes them very vulnerable to severe damage in an earthquake. Some school districts in Utah have ongoing plans to either strengthen or replace these older buildings. These districts need to be congratulated on their efforts. And while many of the other districts are aware of the problem, they have not been able to find the necessary funding to address these issues. We recognize the dilemma that these school districts face as they try to balance all of the different needs in their districts. Our communities need to support our districts as they address life safety concerns from earthquakes.
Owners of older commercial buildings need to be aware of some simple things that can be done to improve their buildings' inherent seismic weaknesses. One example is the Utah Parapet Ordinance. This ordinance was passed into law in the early 1990s and specifies that whenever a building is being reroofed, the parapets and other projections above the roof of the building must be braced for seismic loads. Unbraced parapets are a source of falling debris on our public sidewalks that can be minimized by following this ordinance. It is our finding, however, that many are not aware of this hazard or this required ordinance to minimize this hazard. While complying with this law will not solve all of the seismic vulnerabilities in older buildings, it does address one important part.
For those with older homes, the state published in 1996 "The Utah Guide for Seismic Improvement of Unreinforced Masonry Dwellings." This book contains guidelines that can help strengthen these older homes. It is intended for use by contractors, repair specialists and homeowners who possess construction skills above a typical "handyman" level. This manual can be found on the state of Utah Web site at des.utah.gov/prepare/EPIcenter1.html.
Again, we thank the Deseret Morning News for bringing to everyone's attention the real earthquake threat that we face along the Wasatch Front. We hope that by educating the residents of Utah about the fact that we do live in a seismically hazardous area, we can, as a community, start addressing these problems before we suffer major losses in an earthquake.
There are laudable efforts in the community to address emergency response after an earthquake. While developing emergency response plans is an important part of earthquake preparedness, wouldn't it be better to strengthen and/or replace our older existing buildings than to have to deal with the severity of the post-earthquake disaster?
Stephen D. Cohen is the principal engineer on the Seismic Committee of the Structural Engineers Association of Utah.