Earthquake-Resistant Design Concepts: An Introduction to the NEHRP Recommended Seismic Provisions for New Buildings and Other Structures [open pdf - 5MB]
"Of the 500,000 or so detectable earthquakes that occur on Planet Earth each year, people will 'feel' about 100,000 of them and about 100 will cause damage. Although most earthquakes are moderate in size and destructive potential, a severe earthquake occasionally strikes a community that is not adequately prepared and thousands of lives and billions of dollars in economic investment are lost. For example, a great earthquake and the fires it initiated destroyed much of San Francisco in 1906 and a significant portion of Anchorage, Alaska, was destroyed by a large earthquake in 1964. Within the past 200 years, major destructive earthquakes also occurred in Charleston, South Carolina, and Memphis, Tennessee. Within the past 50 years, smaller but damaging earthquakes occurred several times in both Los Angeles and Seattle. Overall, more than 20 states have a moderate or high risk of experiencing damaging earthquakes. Earthquakes are truly a national problem. One of the key ways a community protects itself from potential earthquake disasters is by adopting and enforcing a building code with appropriate seismic design and construction standards. The seismic requirements in U.S. model building codes and standards are updated through the volunteer efforts of design professionals and construction industry representatives under a process sponsored by the Federal Emergency Management Agency (FEMA) and administered by the Building Seismic Safety Council (BSSC). At regular intervals, the BSSC develops and FEMA publishes the NEHRP (National Earthquake Hazards Reduction Program) Recommended Seismic Provisions for New Buildings and Other Structures (referred to in this publication as the NEHRP Recommended Seismic Provisions or simply the Provisions)."
United States Federal Emergency Management Agency: http://www.fema.gov