Project
goals and objectives 
The primary objective of the
proposed research effort is the development of stateoftheart numerical
modeling techniques for use in simulating the earthquake performance
of older reinforced concrete buildings. The OpenSees analysis platform
will be used as a basis for model development and the Nuys Testbed Building
will be used as an example structure. The Year 6 research effort will
building on a previously developed model of the Van Nuys building to
1) improve simulation of inelastic structural response, 2) enable prediction
of structural and nonstructural damage and economic loss, and 3) predict
the impact of the FEMA 356 retrofit scheme on damage and loss.

Role
of this project in supporting PEER’s vision 
The results
of this project support the PEER research effort in several ways. First
this study uses the OpenSees platform to simulate the earthquake response
of an older reinforced concrete building frame and thereby contributes
to evaluation, verification and advancement of the OpenSees platform.
This analysis platform is central to the PEER research effort. Second,
this study uses multiple component models developed by various researchers
to predict response and thereby contributes to the evaluation, verification
and advancement of these component models. Third, the results of this
study define the relationship between intensity measure and engineering
demand parameters for the Van Nuys testbed building. By quantifying the
uncertainty in EDPs associated with modeling decision, the results of
this investigation contribute to modeling of the uncertainty of the IMEDP
relationship. Fourth, this project is required to demonstrate the application
of the PEER lossassessment methodology to the Van Nuys testbed building. 
Methodology
employed 
Classical methods for nonlinear,
dynamic, structural analysis were employed to generate simulated response
histories. Classical statistical methods will be employed to quantify
variability in EDPs associated with epistemic and alleatory uncertainty
in model parameters. 
Brief
description of past year’s accomplishments and more detail on
expected Year 6 accomplishments 
Year 5 accomplishments include the following:
 the development of a parameterized model of the Van Nuys building
using the OpenSees platform, this approach facilitates investigation
of the impact on predicted EDPs of alleatory uncertainty using a
Monte Carlo approach and epistemic uncertainty using a decisiontree
approach,
 development/identification of a baseline model of the Van Nuys
building that provides representation of column splice failure, column
shear
failure and limited flexural ductility of beams and columns,
 use
of the baseline
model to generate EDPs for three earthquake hazard levels,
 evaluation
of the impact of modeling decisions such as concrete material model
parameters, column shear strength model, level of mesh refinement,
damping, column
plastichinge length, etc. on prediction of EDP (Figures
1 and 2).


Figure 1: Base shear versus roof displacement for one exterior and
one interior frame of the Van Nuys Holiday Inn building. Different
response histories are shown for models of the structure that include
different representations of column shear and splice strength.
Larger View
Figure 3a: Maximum story drifts for a the baseline model of
the Van Nuys building subjected to an earthquake ground motion record
with 10% probability of exceedance in 50 years. Different maximum drift
values correspond to different models of the structure that include different
levels of damping (x = 2%M1, x=8%M2), different concrete compressive
strength (fc = design strengthM14), different beamcolumn element formulation
(nlbcM5), different column hinge length (lp=0.5dM6), different effective
slab width (_=0.22M7) and different column shear strength values (computed
shear strength is reduced 10%  M16 and computed shear strength is increased
by 10%  M17).
Larger View

Figure 2: Base shear versus roof displacement for one exterior
and one interior frame of the Van Nuys Holiday Inn building. Different
response histories are shown for models of the structure that include
different beamcolumn element formulation (nlbcM5), different column
hinge length (lp=0.5dM6), different effective slab width (_=0.22M7)
and different joint flexibility (flexibleM8).
Larger View
Figure 3b: Maximum story drifts for a model of the Van Nuys building,
which does not include simulation of column shear failure, subjected
to an earthquake ground motion record with 10% probability of exceedance
in 50 years. Different maximum drift values correspond to different
models of the structure that include different levels of damping
(x = 2%M1, x=8%M2), different concrete compressive strength (fc
= design strengthM14), different beamcolumn element formulation
(nlbcM5), different column hinge length (lp=0.5dM6) and different
effective slab width (_=0.22M7).
Larger View


Year 6 accomplishments will include the following:
 Introduction
of three beamcolumn joint models into the OpenSees model of the
Van Nuys building, evaluation of these models and the impact of
modeling joint deformation on building frame response.
 Introduction
of an improved shearcritical column model (the model developed
by Moehle and Elwood will be used) into the OpenSees model of the Van
Nuys building,
evaluation and further development of this model as is necessary,
and assessment of the impact of model formulation and model parameters
on prediction of EDPs.
 Introduction into of foundation elements
into
the model and assessment of the impact of these elements on predicted
EDPs.
 A formal sensitivity study to quantify the uncertainty
in
the
IMEDP relationship associated with modeling decision.
 In
collaboration with other PEER researchers, the results of the Van
Nuys simulation
will be use to predict economic loss resulting from earthquake
ground motion.

Other
similar work being conducted within and outside PEER and how this project
differs 

Plans
for Year 7 if this project is expected to be continued 

Describe
any instances where you are aware that your results have been used
in industry 

Expected
milestones 
Milestones mirror the Year 6 accomplishments identified above.

Deliverables 
Deliverables associated with Year 6 accomplishments identified
above:
 Simulated EDPs for the suite of Van Nuys ground motion records,
including joint load and deformation demands, for a single beamcolumn
joint element formulation
 Simulated EDPs for the Van Nuys ground
motion records
 Simulated EDPs for the Van Nuys ground motion
records, including foundation load and deformation demands
 Sensitivities
 Economic loss predictions for three earthquake hazard levels
