China Seismic Intensity Scale
The Chinese seismic intensity scale (Chinese中国 地震 烈度 表, pinyin Zhōngguó dìzhèn lièdù biǎo, English China Seismic Intensity Scale, short CSIS), or not quite accurate Liedu scale, is a national standard for the design of seismic intensity of earthquakes in the people's Republic of China. Similar to the European macroseismic scale, on which the CSIS refers, an earthquake event is in 12 intensity classes or Liedu (烈度, lièdù, literally " degree of severity " ) classified. The intensity classes are designated by Roman numerals from I (not felt) to XII ( altered landscape ). In Taiwan and Hong Kong other intensity scales are used.
History
The scale was (CEA, Chinese Earthquake Administration ) officially released initially in 1980 by the China Earthquake Administration and is therefore often with their original names China Seismic Intensity Scale ( 1980) referred to. It was later revised in 1999 by the National Quality and Technology Supervision Administration ( National Agency for Control of Quality and Technology), now General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China ( General Authority for Quality Supervision, Inspection and Quarantine the PRC ), short AQSIQ, as a national standard or GB coding, Row GB / T 17742-1999, introduced. The standard was subjected to revision not long before the 2008 Sichuan earthquake.
Applications
The evaluation of past earthquakes after Liedu scale is a valuable tool in the reinforcement of existing and future buildings against earthquakes. The National Standard Code for Seismic Design of Buildings (Standard for the seismic design of buildings, GB 500011-2001 ) was published in 2001 and revised in part shortly after the Sichuan earthquake in 2008. The standard contains a list of cities for certain degrees of intensity, where every building has to withstand.
Chinese seismic intensity scale
In contrast to magnitude scales, which expresses the seismic energy generated by an earthquake, describes an intensity scale as the Chinese seismic intensity scale, the impact that it has in a particular place. The intensity level is determined by a combination of partially subjective measures such as the effects on the human senses, the impact on building or landscape and movement measurements. Building damage are described refined by a combination of verbal descriptions and the application of a numeric index between 0 (no damage ) to 1 ( complete destruction ).
The focus is on the intensities I to V to affect people between VI and X of damage to buildings and landscape effects - here the human sensation serves only as additional information - and in the intensities of XI and XII primarily on landscape changes. For a correct classification of the individual features are more detailed instructions.
The table below is an unofficial translation of the appendix I of GB / T 17742-1999.
Note the qualifiers " very few " - < 10%; " few " - 10 % - 50 %; "most" - 50% - 70 %; "Majority " - 70 % - 90 %; "predominantly" -> 90%.