Seismic reliability of deteriorating reinforced concrete (RC) bridges - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 514

noninformative prior can be used to refl ect the fact that little or nothing is
known before collecting C ik .

Structural capacity of, and seismic demand on, an example RC bridge
subject to deterioration

This section gives an example of the effects of deterioration, specifi cally
corrosion (although this could include other expansive deterioration mech-
anisms), on the structural capacity of and the seismic demand on a typical
RC bridge. This example is taken from Gardoni et al. (2003) and Choe
et al. (2009). Figure 19.3 shows an example RC bridge - a single-bent
highway overpass. The values of the design variables listed in Table 19.1 are

L

D s

K abt

A A

H

D

A-A

K soil

19.3 Confi guration of the example bridge (not to scale) (Gardoni et al.
2003). © 2003 Taylor & Francis.

Table 19.1 Variables for the pristine single-bent bridge

Value/
distribution Description Variable

Span length (right and left) L [mm] 18 300

Span-to-column height ratio L / H 2.4

Column-to-superstructure dimension ratio D / D s 0.75

Concrete nominal strength f ′ c [MPa] LN(27.6, 2.76)

Reinforcement nominal yield strength f y [MPa] LN(448.2, 22.4)

Initial longitudinal reinforcement ratio of column ρ 2.0% l 0

Initial transverse reinforcement ratio of column ρ 0.7% s 0

Soil stiffness based on NEHRP groups (FEMA
273/274, 1997)

K soil B

Additional bridge dead load (as a ratio of the
dead weight)

r N(0.1, 0.025)

Note: LN( ) indicates the lognormal distribution, N( ) indicates the normal
distribution, and the two parameters provided for these two distributions are the
mean and standard deviation, respectively.
Source: Adapted from Choe et al . (2009).