Page 194 - Handbook of Materials Failure Analysis

190 CHAPTER 8 Seismic risk of RC water storage elevated tanks

analysis. Displacement capacity curves (therefore deformability) are plotted for the
buildings studied. These curves depend on the characteristics of these buildings and
not a seismic load. The different degrees of damage corresponding to the displace-
ments on the curve are located. By correlating the capacity curve of the displacement
building with a maximum displacement caused by seismic motion of the soil given,
determined by a proposed method in the document, a point called “performance point”
is obtained. Its position, relative to the desired level of performance, indicates that this
level is reached or not.
The Federal Emergency Management Agency (FEMA) 310 method developed in
1998 and published in the United States by the FEMA is presented as a manual [21].
In this method, three levels of evaluation are proposed, level 1 is a presumption of
vulnerability, level 2 is quantitative analysis, and level 3 is in-depth analysis.
The HAZUS 99 method developed in 1999 and edited in the United States by the
FEMA is presented as a manual. This manual provides a detailed methodology for
assessing vulnerability to urban scale. The aim is to provide an estimate of losses that
area or region may suffer during an earthquake. In this method, three types of anal-
ysis are proposed (briefly, standard, and deepened).
In Italy, the procedure to qualify the seismic vulnerability of buildings has been
proposed for the first time by Benedetti et al. [5] and then this method was developed
by the Gruppo Nazionale per la Difesadai Terremoti of the Italian Consiglio Nazio-
naledelle Ricerche (CNR-GNDT). This method which is the subject of our interest
will be explained in Section 3.
We can also mention the RISK-UE project [22] which is an advanced approach to
earthquakes risk scenarios with applications to different European towns, financed
by the European Commission which is a major step toward the development of a
European methodology to assess and mitigate the seismic risk of lifelines and essen-
tial facilities in Europe. The RISK-UE project is based on the assessment of the vul-
nerability index for a given current building. This index is a function of the
constructive typology and different factors that can change its behavior. The
RISK-UE project was used to treat the seismic vulnerability of seven pilot European
cities (Thessaloniki, Catania, Nice, Bucharest, Sofia, Barcelona, and Bitola) [6].

3 VULNERABILITY METHOD OF CNR-GNDT
This method evaluates the seismic vulnerability of buildings, determining as a nor-
malized index of vulnerability, which is obtained with the aid of survey forms which
are filled in for one building or a group. The CNR-GNDT method was originally
applied to stone rubblework buildings and reinforced concrete buildings, and a very
detailed procedure exists for each one. The method is very easy to apply and it con-
siders the structural characteristics of the buildings, such as type of construction,
building’s use, quality of materials, structural system, geometric aspects of the struc-
ture, building’s state of preservation, etc. These characteristics are quantified as
parameters and are evaluated considering 11 factors, and a class, score, and weight