Using a performance-based earthquake engineering (PBEE) approach to estimate structural performance targets for bridges - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 538

20.5 Performance-based seismic evaluation of
ordinary highway bridges

During 2004-2008, a detailed analytical study on the seismic response of
ordinary highway bridges was conducted at UC Davis, California. The
primary objective of the study was to quantify the effects of near-fault verti-
cal ground motions on the seismic response of single bent, two-span highway
overpasses. Results from the study were published in a series of papers;
Kunnath et al. (2008), Gülerce and Abrahamson (2010), and Gülerce et al.
(2012), focusing mainly on the structural demand due to vertical ground
motion component. The study followed the PEER-PBEE framework by
developing PSDMs for the particular structures using scalar- and vector-
valued IMs, and by performing many scalar- and vector-valued PSHA anal-
yses to address the question of when the vertical component should be
included in design. Results of that study will be used as an example to
explain an application of the PBEE methodology. The fl owchart of the
major steps is provided in Fig. 20.2.
The initial step of the process was the selection of ground motion record-
ings to be used in the nonlinear dynamic analyses of the bridge prototype.
A subset of 56 near-fault recordings (rupture distance smaller than 50 km)
having the strongest horizontal components (horizontal PGA is greater
than or equal to 0.5 g ) was selected from the PEER-NGA database (Chiou

Step 2: Modeling the
bridge prototype and
nonlinear dynamic
analyses

Step 1: Selection of
ground motion
recordings

Step 4: Building
PDSMs
(scalar and vector-
valued)

Step 3: Selection of
EDPs and IMs

Step 5: Scalar and
vector-valued PSHA
including the PDSMs

Step 6: Structural
demand hazard
curves

20.2 PBEE framework for evaluating the vertical ground motion effects
on the structural response.