The China seismic intensity scale (CSIS) is a national standard in the

People's Republic of China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

used to measure

seismic intensity Seismic intensity scales categorize the intensity or severity of ground shaking (quaking) at a given location, such as resulting from an earthquake. They are distinguished from seismic magnitude scales, which measure the magnitude or overall stren ...

. Similar to EMS-92 on which CSIS drew reference, seismic impacts are classified into 12 degrees of intensity, or ''liedu'' (, literally "degrees of violence") in

Roman numerals Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, ...

from I for insensible to XII for landscape reshaping. The scale was initially formalized by the China Earthquake Administration (CEA) in 1980, therefore often referred to by its original title as "China Seismic Intensity Scale (1980)". It was later revised, and adopted as a national standard, or Guobiao, series GB/T 17742-1999 by then National Quality and Technology Supervision Administration (no
General Administration of Quality Supervision, Inspection, and Quarantine of P.R.C.
AQSIQ) in 1999. The standard was set for revision not long before the 2008 Sichuan earthquake.

''Liedu'' scale

Unlike the magnitude scales that objectively estimate the released seismic energy, ''liedu'' denotes how strongly an earthquake affects a specific place. It is determined by a combination of subjective evaluations (such as human senses and building damages) and objective kinetic measures. Building damages are further refined with a combination of descriptive qualifiers and a numeric evaluation process. The following is an unofficial translation of the Appendix I of GB/T 17742-1999. Notes about qualifiers: "very few" - <10%; "few" - 10% - 50%; "most" - 50% - 70%; "majority" - 70% - 90%; "commonly" - >90%.

Applications

Historic local seismic liedu is an important reference in quake proofing existing and future buildings. The national standard Code for Seismic Design of Buildings (GB 500011-2001) published in 2001 and partially revised shortly after the 2008 Sichuan earthquake includes a list of liedu that each building in designated cities is expected to resist.

Notes and references

External links

* {{Seismic scales Seismic intensity scales Guobiao standards Earthquake engineering Science and technology in China 1999 introductions

''Liedu'' scale

Applications

See also

Notes and references

External links