Submitted by seaoc on
By Cameron Black, Primary Contributor and Member, SEAOC Seismology Committee
Seismic isolation is recognized as the most effective way to protect structures and minimize, or even potentially eliminate, damage caused by earthquakes. Seismic isolation is a mature technology that has been used on thousands of buildings and bridges around the world over the last 35 years. To date, there are more than 6,500 isolated buildings in Japan, a reported 5,000 buildings in China, 700 in Russia, 400 in Turkey and more than 125 buildings in the United States.
In the US, seismic isolation has typically been used in government buildings, hospitals, and emergency centers where immediate occupancy and continued operation is essential to public health and safety. Seismic isolation also finds application in museums and data centers where protection of valuable or sensitive building contents is a major concern, as well as manufacturing facilities where downtime following a seismic event could lead to significant economic impact. The increased seismic performance of buildings utilizing seismic isolation can also translate into reduced life-cycle costs due of the reduced likelihood of building damage resulting from an earthquake.
In light of the performance and life-cycle benefits that seismic isolation provides, the SEAOC Protective Systems Subcommittee aims to expand the understanding and promote the use of seismic isolation through a Blue Book article entitled “When to Consider Seismic Isolation”. The committee recognizes that a variety of economic, regulatory and technical issues affect the selection of seismic isolation and seeks to inform the reader of how these issues might affect a particular project. The subject matter is targeted to a broad audience including engineers, architects and project stakeholders. The article introduces the main aspects of seismic isolation, discusses its benefits, outlines particularly favorable conditions for its implementation, and expands on the circumstances where its use may be more challenging. A list of 60 seismically isolated buildings in the United States - grouped into building type or occupancy use - is presented for reference and the article concludes with a list of technical and online references for those interested to learn more.
Download the "When to Consider Seismic Isolation" Blue Book article from the SEAOC Bookstore -- FREE for SEAOC Members: Log in first and then click HERE to access.
The SEAOC Blue Book - Seismic Design Recommendations is the premier publication of the SEAOC Seismology Committee. Since 1959, the SEAOC Blue Book has been a preeminent publication of earthquake engineering. Blue Book editions from 1959 to 1999 served the dual purpose of commentary to and recommended modifications to the seismic design provisions of the Uniform Building Code, at that time adopted in most western and central states. Starting with the 2009 Edition, the Blue Book format was shifted to a series of white papers, and the focus was shifted to:providing insight and discussion of earthquake engineering concepts, interpretations of sometimes ambiguous or conflicting provisions of various codes, standards, and guidelines, and practical guidance on design implementation. These changes were adopted in recognition of changes in the national code development process and other available publications addressing code provision commentary, such as the NEHRP Recommended Provisions For New Buildings and Other Structures and ASCE/SEI 7.
The SEAOC Blue Book is available for download free of charge to SEAOC members. In addition to the new article on seismic isolation, the 2009 Blue Book Compilation and two articles from October 2013 are available in the publications portions of the SEAOC web site. Once logged in as a member, PDF files can be downloaded free of charge. Links to these three items are:
For those to prefer a printed document, printed versions of the 2009 compilation can be purchased through the ICC bookstore web site. Thank you to the members of the SEAOC Seismology committee who participated in development of the new base isolation article.