EARTHQUAKE & TECHNOLOGY

Earthquake & Technology



Earthquake & Technology

Introduction

A predictable cycle of activity occurs after every major earthquake. Emergency preparedness systems are tested and found wanting. The print and electronic media move in to cover the disaster for the news hungry public. Political leaders visit disaster sites to express concern for the victims and to capitalize on media opportunities. Universities and research organizations submit proposals for more studies on all aspects of the disaster. Then, media interest diminishes, and life returns to normal for those unaffected by the earthquake until another earthquake repeats the cycle. This cycle is a manifestation of the human trait that focuses on cures rather than prevention. Recently, California has been very receptive to adopting codes and government response plans to mitigate the hazards of an earthquake, and therefore provide a policy template for other states that are threatened by seismic activity. (Cutcliffe, 2010)

Discussion

Most of California's population and industry are located in zones of high seismicity, and the Federal Emergency Management Agency (FEMA) estimates that a 7.5 to 8.3 Richter magnitude earthquake in an urban area could cause up to $60 billion in damage. Such an earthquake could cripple the state's public and private economies and have a negative effect on the world market.

The California Building Code offers only minimal protection from seismic damage, i.e., a structure should not be damaged in a minor earthquake, damaged beyond repair in a moderate earthquake, nor collapse in a major earthquake. However new technologies, such as seismic isolation, can mitigate both structural and building contents damage and are becoming available to government and industry. There is a need for design professionals, building officials, planners, and building owners to become aware of these new technologies, the criteria for their use, and how to incorporate them into practice. (Cahan, 2002)

The Uniform Building Code provides minimal seismic protection determined acceptable by local governments, but Code specifications do not prevent structural damage nor ensure the use of a building after an earthquake.

Such limited protection is not consistent with the needs of commerce or emergency facilities, which must remain operational after an earthquake, nor does it protect the contents of a building. Two earthquakes which struck near the Lawrence Livermore National Laboratory in California, within two days of each other in January of 1980, caused a total of $10 million in damage. Nearly half of the damage was to laboratory equipment, testing systems, and other building contents. (Chopra, 2005)

Earthquake design in California is dictated by state and local government interpretation of the uniform Building Code, which provides specifications for minimum protection to structures. Structures built to code specifications should not be damaged in a minor earthquake up to 4.5 on the Richter scale (M4.5), structurally damaged by a moderate event up to M6.5 Richter, nor collapse in a major earthquake above M6.5 Richter.

New seismic technology designed to protect buildings, building contents and building function in earthquakes in the M8-plus Richter range is available to design professionals and the construction ...