Assessing seismic risks for new and existing buildings using performance-based earthquake engineering (PBEE) methodology - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 308

Table 12.1 Sample repair quantity table for the performance group shown in
Fig. 12.2

Repair item Unit DS1 DS2 DS3 DS4

Water damage sf** 0 0 10 000 20 000

Remove furniture sf 0 4000 10 000 20 000

Ceiling system removal sf 0 0 0 20 000

MEP* removal sf 0 0 500 2 000

Replace ceiling tiles sf 0 2500 8 000 8 000

Replace ceiling system sf 0 0 0 20 000

MEP* replacement sf 0 0 500 2 000

* MEP = Mechanical, electrical and plumbing.

** sf = square feet.

After the performance groups have been identifi ed, building data, such
as as-built documents or in-use surveys, are employed to quantify the repair
quantities of the components of each performance group in the building.
For example, square footage of partition walls and number of pocket doors
may be computed. Because each damage state is defi ned according to the
repair action, the total repair quantities for each item in the performance
group at different damage states can be defi ned according to the functional-
ity of the structure. Table 12.1 shows an example of the repair quantities
for each item in the sample performance group shown in Fig. 12.2 at differ-
ent damage states. Additional damage states and repair items can be added
for different performance groups.

Conduct seismic hazard analysis and ground motion record selection

A conventional seismic hazard analysis is conducted, taking into account
the site and the basic dynamic characteristics of the building. One outcome
of the seismic hazard analysis is a hazard curve that quantifi es expected
ground motion intensity measures as a function of exceedance probability
considered in the PBEE analysis of the building. The hazard curve and
engineering judgment are used to identify several discrete hazard levels for
which the performance of the building will be further examined. Another
outcome of the seismic hazard analysis is a suite of ground motions repre-
senting the seismicity of the site at different seismic hazard levels. For
example, a suite of ground motion records representing the seismic hazard
with a 10% probability of exceedance in 50 years at the site may be pro-
vided. A typical suite comprises several ground motions with their intensity
scaled to the level implied by the seismic hazard. The motions may be
further divided into subclasses by record type, such as near-fi eld or far-fi eld
ground motions.