Chinese 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 , CSIS for short ), or not quite precise Liedu scale , is a national standard for measuring the seismic intensity of earthquakes in the People's Republic of China . Similar to the European Macroseismic Scale , to which the CSIS refers, an earthquake event is classified into 12 intensity classes or Liedu ( 烈度 , lièdù , literally "degree of severity"). The intensity classes are designated with Roman numerals from I (not noticeable) to XII (changing the landscape). Different intensity scales are used in Taiwan and Hong Kong .
history
The scale was initially officially published by the China Earthquake Administration (CEA) in 1980 and is therefore often referred to by its original name, China Seismic Intensity Scale (1980) . It was later revised and in 1999 by the National Quality and Technology Supervision Administration , now the General Administration of Quality Supervision, Inspection, and Quarantine of Peoples Republic of China (General Authority for Quality Assurance, Inspection and Quarantine PR China), AQSIQ for short , introduced as a national standard or Guobiao , GB / T 17742-1999 series. The standard was suspended for revision not long before the 2008 Sichuan earthquake .
Applications
The evaluation of past earthquakes according to the Liedu scale is a valuable aid in strengthening existing and future structures against earthquakes. The National Standard Code for Seismic Design of Buildings (Standard for the earthquake-proof construction of buildings, GB 500011-2001) was published in 2001 and partially revised shortly after the 2008 Sichuan earthquake. For specific cities, the standard contains a list of intensity levels that every building must withstand.
Chinese seismic intensity scale
Unlike magnitude scales , which express the seismic energy generated by an earthquake, an intensity scale like the Chinese Seismic Intensity Scale describes the impact it has on a particular location. The degree of intensity is determined using a combination of partly subjective measured variables such as the effects on the human senses, the effects on buildings or the landscape and movement measurements. Damage to buildings is described in a more refined way using a combination of verbal descriptions and the use of a numerical index between 0 (no damage) and 1 (complete destruction).
With intensities I to V, the focus is on effects on people, between VI and X on building damage and landscape effects - here human perception is only used as additional information - and with intensities XI and XII primarily on changes in the landscape. Further detailed instructions are provided for the correct classification of the individual characteristics.
The following table is an unofficial translation of Appendix I of GB / T 17742-1999.
| Liedu (intensity) | Perceptions of people on the ground | Degree of building damage | Other damage | Horizontal movement on the ground | ||
| Damage | Mean Damage index | Max. Acceleration [m / s 2 ] | Max. Speed [m / s] | |||
| I. | Not noticeable | |||||
| II | Noticeable only by very few people who are at rest | |||||
| III | Only noticeable by a few people who are at rest | Doors and windows rattle slightly | Slight swing of hanging objects | |||
| IV | Noticeable by most people inside the building and some people outside. Some sleeping people wake up. | Doors and windows rattle | Clear swinging of hanging objects, rattling of pots | |||
| V | Generally in buildings and noticeable by many outside. Most of the sleeping people wake up. | Noise from swinging doors, windows and building structures, dust falling, small cracks in plaster, falling of some roof tiles and bricks from chimneys | Rocking or rotating unstable objects | 0.31 (0.22-0.44) |
0.03 (0.02-0.04) |
|
| VI | Most people can no longer stand safely, and some run outside in fear | Damage - cracks in walls, tiles falling, ripping open or falling of some chimneys on gables | 0-0.10 | Crevices in river banks and soft ground, in places sand volcanoes from water-saturated layers of sand, cracks in individually standing chimneys | 0.63 (0.45-0.89) |
0.06 (0.05-0.09) |
| VII | The majority walk outside in fear, which is also noticeable to motorcyclists and people in moving cars | Light destruction - local destruction, cracks. The building can continue to be used with light or without repairs | 0.11-0.30 | Collapse of river banks, often sand volcanoes from water-saturated layers of sand, many crevices in soft ground, moderate destruction of most of the individual chimneys | 1.25 (0.90-1.77) |
0.13 (0.10-0.18) |
| VIII | Most people sway a lot and walking is difficult. | Mediocre destruction - structural damage, no further use possible without repairs | 0.31-0.50 | Crevices even in hard, dry ground. Severe destruction of most of the individual chimneys, the breaking of tree tops, death of people and cattle from building destruction | 2.50 (1.78-3.53) |
0.25 (0.19-0.35) |
| IX | Moving people fall | Severe destruction - severe structural damage, sometimes collapse, repairs difficult | 0.51-0.70 | Many crevices even in hard, dry ground, possibly crevices and shifts in solid rock. Landslides and basic movements are common. The collapse of many individual chimneys, the breaking of tree tops, death of people and cattle due to building destruction | 5.00 (3.54-7.07) |
0.50 (0.36-0.71) |
| X | Cyclists fall, people without a secure footing fall down, feeling of being thrown up | Majority of the buildings collapse | 0.71-0.90 | Breakage of solid rock and formation of earthquake crevices, the collapse of bridge arches founded in rock, damage to the foundation or the collapse of most of the individually standing chimneys | 10.00 (7.08-14.14) |
1.00 (0.72-1.41) |
| XI | Widespread building collapse | 0.91-1.00 | Long-lasting earthquake crevices, extensive landslides | |||
| XII | Drastic changes in the landscape, mountains and rivers | |||||
Comment on the qualifiers: "very few" - <10%; "few" - 10% - 50%; "most" - 50% - 70%; "Majority" - 70% - 90%; "predominantly" -> 90%.
References and comments
- ↑ "Liedu" also refers to other intensity scales (cf. 麥加利 地震 烈度Mercallis scale )
- ↑ Chen Dasheng, Shi Zhenliang, Xu Zonghe, Gai Guangyi, Yan Jiaquan, Xiao Chengye, Feng Yijun (陈达生 、 时 振 梁 梁 、 徐宗 和 、 高 光 伊 、 鄢 家 家 全 、 肖 承 邺 、 冯义钧): China . 承 邺 、 地震 烈度 冯义钧): China表) ( Chinese ) General Administration of Quality Supervision, Inspection, and Quarantine of PRC. April 26, 1999. Archived from the original on October 29, 2008. Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved September 14, 2008.
- ↑ Revision of "China Seismic Intensity Scale" started (《中国 地震 烈度 表》 修订 工作 启动) ( Chinese ) China Earthquake Administration (中国 地震 局). April 26, 1999. Retrieved September 14, 2008.
- ↑ Xu Zhengzhong, Wang Yayong et al. (徐正忠 、 王亚勇 等): Code for seismic design of buildings (GB 500011-2001) (partially revised in 2008), Appendix A (《建筑 抗震 设计 规范》 （GB 500011－2001） （2008 年 局部 修订） 附录 A我国 主要 城镇 抗震 设防 烈度 、 设计 基本 地震 加速度 和 设计 地震 分组) . Ministry of Housing and Urban-Rural Development of PRC (MOHURD, 中华人民共和国 住房 和 城乡 建设部). 2001. Retrieved September 16, 2008.
- ↑ a b Chen Dasheng, Shi Zhenliang, Xu Zonghe, Gao Guangyi, Yan Jiaquan, Xiao Chengye, Feng Yijun (陈达生 、 时 振 梁 梁 、 徐宗 和 、 高 高 光 伊 、 鄢 家 全 、 肖 承 邺 、 冯义钧): 3 China Seismic Scale 3 中国 地震 烈度 表) ( Chinese ) General Administration of Quality Supervision, Inspection, and Quarantine of PRC. April 26, 1999. Archived from the original on July 7, 2011. Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved September 14, 2008.
Web links
- China Earthquake Administration (CEA)
- General Administration of Quality Supervision, Inspection, and Quarantine of PRC