One of the most comprehensive damage state surveys is that by Whitman et al. [1973]. This study was based on a survey of 5+ storey buildings following the 1971 San fernando earthquake. Each damage state is identified by [1] a subjective description of physical damage and [2] an objective ratio of repair cost to replacement cost. The damage states are believed to have general applicability.
|
Damage State |
Structural damage |
Non-structural Damage |
Damage Ratio [%] |
Description of Damage States |
|
0 |
None |
None |
0-0.05 |
No Damage |
|
1 |
None |
Minor |
0.05-0.3 |
Minor non-structural damage – a few walls and partitions cracked; incidental mechanical and electrical damage |
|
2 |
None |
Localised |
0.3-1.25 |
Localised non-structural damage – more extensive cracking [but still not widespread]; possibly damage to elevators and/or other mechanical electrical components |
|
3 |
Not Noticeable |
Widespread |
1.25-3.5 |
Widespread non-structural damage – possibly a few beams and columns cracked, although not noticeable |
|
4 |
Minor |
Substantial |
3.5-7.5 |
Minor structural damage – obvious cracking or yielding in a few structural members; substantial non-structural damage with widespread cracking |
|
5 |
Substantial |
Extensive |
7.5-20.0 |
Substantial structural damage requiring repair or replacement of some structural members; associated extensive non-structural damage |
|
6 |
Major |
Nearly total |
20-65.0 |
Major structural damage requiring repair or replacement of many structural members; associated non-structural damage requiring repairs to major portion of interior; building vacated during repairs |
|
7 |
Building condemned |
100 |
Building condemned |
|
|
8 |
Collapse |
100 |
Collapse |
|
In 1975 Whitman et al. provided Central Damage Ratios [%] together with an abbreviated set of Damage States as shown below.
|
Damage State |
Central Damage Ratio [%] |
|
0 – NONE |
0 |
|
L – LIGHT |
0.3 |
|
M – MODERATE |
5 |
|
H – HEAVY |
30 |
|
T – TOTAL |
100 |
|
C – COLLAPSE |
100 |
The Hirschberg et al. [1978] version is slightly different
|
Damage State |
Structure Condition |
|
None |
No damage |
|
Light |
Minor ceiling tile or partition cracking; possible damage due to missiles |
|
Moderate |
Many partitions cracked or ceiling tiles fallen down; a few structural members appear to be stressed beyond yield level. |
|
Heavy |
Significant structural members with structural damage, or damage to a structural system, roof having major damage |
|
Very Severe |
Major damage; structure standing but will probably be taken down |
|
Collapse |
Structure does not remain standing |
Rojahn [1986] uses a similar scale for ground shaking damage states, based on expert opinion.
|
Damage State |
Damage
Factor Range |
Central
Damage Factor |
|
1 – None |
0 |
0 |
|
2 – Slight |
0-1 |
0.5 |
|
3 – Light |
1-10 |
5 |
|
4 – Moderate |
10-30 |
20 |
|
5 – Heavy |
30-60 |
45 |
|
6 – Major |
60-100 |
80 |
|
7 – Destroyed |
100 |
100 |
Czarnecki et al. [1986] used the same categories as Rojahn [1986] except that the first and last categories were omitted and the remaining five were re-numbered so that 1 = Slight and 5 = Major.
References
Czarneck R m, Scholl R E, and Malik L E, 1986, Techniques for estimating earthquake probable loss for buildings and contents, in C Scawthorn [ed.], Techniques for rapid assessment of seismic vulnerability, American Society of Civil Engineers, Structures Congress ’86, New Orleans, 67-78.
Hirschberg J C, Gordon P and Petak W J, 1978, Natural hazards: socio-economic impact assessment model, NSF/PRA-7509998/5, J H Wiggins and Co, Redondo Beach, California.
Rojahn C, 1986, ATC Methodology and data for rapid assessment for seismic vulnerability, in C Scawthorn [ed.], Techniques for rapid assessment of seismic vulnerability, American Society of Civil Engineers, Structures Congress ’86, New Orleans, 21-40.
Whitman R V, Reed J W, and Hong S-T, 1973, Earthquake damage probability matrices, Proc 5th World Conf on Earthquake Engineering, Rome, 2531-2540.
Whitman R V, Biggs J M, Brennan J E, Cornell C A, de Neufville R L, Vanmarcke E H, 1975, Seismic Design Decision Analysis, Journal of the Structural Division, ASCE, ST5, 1067-1084.
