GB/T 17742-2020 The Chinese seismic intensity scale English
1 Scope
This standard specifies the grade of seismic intensity, the category of houses for assessing seismic intensity, and the assessment method of seismic intensity. The assessment indexes include seismic damage of houses, human feelings, response of implements, earthquake damage of lifeline engineering, other earthquake damage phenomena and seismic intensity measured by instruments. The assessment method is a multi-index method which comprehensively uses macro investigation and instrument measurement.
This standard is applicable the assessment of seismic intensity.
2 Terms, definitions, symbols and abbreviations
2.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1.1
seismic intensity
ground motion caused by earthquake and the intensity of its influence
2.1.2
damage index
quantitative index of earthquake damage degree of buildings
Note: the number between 0.00 and 1.00 indicates the degree of earthquake damage from weak to strong
2.1.3
mean damage index
weighted mean value of earthquake damage index of similar buildings
Note: the mean damage index is the sum of the products of the ratio of houses damaged by earthquakes at all levels and their corresponding earthquake damage indexes.
2.1.4
ground motion
ground motion caused by earthquake
[GB/T 18207.2-2005, definition 6.1.1]
2.2 Symbols and abbreviations
For the purpose of this document, the following symbols and abbreviations apply.
IA: calculated value of seismic intensity obtained by PGA
IV: calculated value of seismic intensity obtained by PGV
II: calculated value of seismic intensity
E-W: East and West
N-S: North and South
U-D: Up and Down
PGA: Peak Ground Acceleration of synthetic ground motion recorded, m/s2
PGV: Peak Ground Velocity of synthetic ground motion recorded, m/s
3 Seismic intensity grade and housing category for accessing seismic intensity
3.1 Seismic intensity
Seismic intensity is divided into 12 grades, which are expressed by Roman numerals (I ~ XII) or Arabic numerals (1~12).
3.2 Definition of quantifiers
Individual, minority, majority, most and vast majority are adopted as quantifiers, and their scope is defined as follows:
a) Some: less than 10%;
b) Minority: 10% ~ 45%;
c) Majority: 40% ~ 70%;
d) Most: 60% ~ 90%;
e) Vast majority: more than 80%;
3.3 Housing category for accessing seismic intensity
Houses used to assess the intensity include the following five types:
a) class A1: earth, brick, stone and other houses without seismic fortification;
b) class A2: bucket-wearing wooden frame houses;
c) class B: brick-concrete structure houses without seismic fortification;
d) class C: brick-concrete structure houses with seismic fortification of intensity VII (7);
e) class D: reinforced concrete frame structure houses with seismic fortification of intensity VII (7).
3.4 Damage grade of houses and corresponding seismic damage index
The damage of houses is divided into five grades: basically intact, slightly damaged, moderately damaged, seriously damaged and destroyed. Their definitions and corresponding seismic damage index d are as follows:
a) basically intact: bearing and non-bearing components are intact, or some non-bearing components are slightly damaged, but can still be used without repair. The corresponding seismic damage index ranges from 0.00≤d<0.10, 0.00 may be taken.
b) slightly damaged: with visible cracks in some load-bearing members, and obvious cracks in non-load-bearing members, which need no repair or need only slight repair to continue use. The corresponding seismic damage index ranges from 0.10≤d<0.30, 0.20 may be taken.
c) moderately damaged: with slight cracks in majority of load-bearing members, and obvious cracks in minority of non-load-bearing members, which may still be used after general repair. The corresponding seismic damage index ranges from 0.30≤d<0.55, 0.40 may be taken.
d) seriously damaged: majority of load-bearing members are seriously damaged, non-load-bearing members partially collapse, and it is difficult to repair the house. The corresponding seismic damage index ranges from 0.55≤d<0.85, 0.70 may be taken.
e) destroyed: majority of load-bearing members are seriously damaged, and the building structure is to be collapsed or has collapsed, it is impossible to repair. The corresponding seismic damage index ranges from 0.85≤d≤ 1.00, 1.00 may be taken.
Standard
GB/T 17742-2020 The Chinese seismic intensity scale (English Version)
GB/T 17742-2020 The Chinese seismic intensity scale English
1 Scope
This standard specifies the grade of seismic intensity, the category of houses for assessing seismic intensity, and the assessment method of seismic intensity. The assessment indexes include seismic damage of houses, human feelings, response of implements, earthquake damage of lifeline engineering, other earthquake damage phenomena and seismic intensity measured by instruments. The assessment method is a multi-index method which comprehensively uses macro investigation and instrument measurement.
This standard is applicable the assessment of seismic intensity.
2 Terms, definitions, symbols and abbreviations
2.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1.1
seismic intensity
ground motion caused by earthquake and the intensity of its influence
2.1.2
damage index
quantitative index of earthquake damage degree of buildings
Note: the number between 0.00 and 1.00 indicates the degree of earthquake damage from weak to strong
2.1.3
mean damage index
weighted mean value of earthquake damage index of similar buildings
Note: the mean damage index is the sum of the products of the ratio of houses damaged by earthquakes at all levels and their corresponding earthquake damage indexes.
2.1.4
ground motion
ground motion caused by earthquake
[GB/T 18207.2-2005, definition 6.1.1]
2.2 Symbols and abbreviations
For the purpose of this document, the following symbols and abbreviations apply.
IA: calculated value of seismic intensity obtained by PGA
IV: calculated value of seismic intensity obtained by PGV
II: calculated value of seismic intensity
E-W: East and West
N-S: North and South
U-D: Up and Down
PGA: Peak Ground Acceleration of synthetic ground motion recorded, m/s2
PGV: Peak Ground Velocity of synthetic ground motion recorded, m/s
3 Seismic intensity grade and housing category for accessing seismic intensity
3.1 Seismic intensity
Seismic intensity is divided into 12 grades, which are expressed by Roman numerals (I ~ XII) or Arabic numerals (1~12).
3.2 Definition of quantifiers
Individual, minority, majority, most and vast majority are adopted as quantifiers, and their scope is defined as follows:
a) Some: less than 10%;
b) Minority: 10% ~ 45%;
c) Majority: 40% ~ 70%;
d) Most: 60% ~ 90%;
e) Vast majority: more than 80%;
3.3 Housing category for accessing seismic intensity
Houses used to assess the intensity include the following five types:
a) class A1: earth, brick, stone and other houses without seismic fortification;
b) class A2: bucket-wearing wooden frame houses;
c) class B: brick-concrete structure houses without seismic fortification;
d) class C: brick-concrete structure houses with seismic fortification of intensity VII (7);
e) class D: reinforced concrete frame structure houses with seismic fortification of intensity VII (7).
3.4 Damage grade of houses and corresponding seismic damage index
The damage of houses is divided into five grades: basically intact, slightly damaged, moderately damaged, seriously damaged and destroyed. Their definitions and corresponding seismic damage index d are as follows:
a) basically intact: bearing and non-bearing components are intact, or some non-bearing components are slightly damaged, but can still be used without repair. The corresponding seismic damage index ranges from 0.00≤d<0.10, 0.00 may be taken.
b) slightly damaged: with visible cracks in some load-bearing members, and obvious cracks in non-load-bearing members, which need no repair or need only slight repair to continue use. The corresponding seismic damage index ranges from 0.10≤d<0.30, 0.20 may be taken.
c) moderately damaged: with slight cracks in majority of load-bearing members, and obvious cracks in minority of non-load-bearing members, which may still be used after general repair. The corresponding seismic damage index ranges from 0.30≤d<0.55, 0.40 may be taken.
d) seriously damaged: majority of load-bearing members are seriously damaged, non-load-bearing members partially collapse, and it is difficult to repair the house. The corresponding seismic damage index ranges from 0.55≤d<0.85, 0.70 may be taken.
e) destroyed: majority of load-bearing members are seriously damaged, and the building structure is to be collapsed or has collapsed, it is impossible to repair. The corresponding seismic damage index ranges from 0.85≤d≤ 1.00, 1.00 may be taken.
