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Tara C. Hutchinson, University of California, Irvine

Performance of Shallow Foundations—2272002
Geoffrey Martin (USC/F), Tara Hutchinson (UCI/F), Chad Harden (UCI/GS), Barbara Chang (UCI/GS)

The goals of PEER researchers (at UCD, USC, and UCI) studying the nonlinear behavior of shallow building foundations are to develop and test procedures to account for this nonlinearity in performance-based design. So far, it is established that soil yielding beneath foundations can be a very effective energy dissipation mechanism. However, foundation yielding may lead to excessive permanent deformations. The primary goal of the research at UCD (Kutter) is to produce archived test data at prototype stress levels. Collaborating researchers at UCI (Hutchinson) and USC (Martin) are using the experimental data provided by UCD and by other sources primarily for performing numerical analysis using OpenSees.

[Full Report]

Performance Characteristics of Bench- and Shelf-Mounted Equipment—5292002
Tara Hutchinson (UCI/F), Gerard Pardoen (UCI/F), Roberto Villaverde (UCI/F), Robert Kazanjy (UCI/O), Samit Ray Chaudhuri (UCI/GS), Jake Bazen (UCI/US)

Modeling and evaluating the response of nonstructural equipment and contents is important for determining the overall economic losses associated with an earthquake event. The particular objectives of studies at UCI, which complement studies by researchers at UCB (Makris), are to characterize the seismic performance of bench and shelf-mounted equipment and contents within a biological/chemical building. In this case, the emphasis is on equipment and contents present in the UC Science building. Our approach, which contributes to the development of performance-based design methodologies, is to develop analytical seismic fragility curves describing the probability of exceedance of a limit state (damage measure DM) given an input (an engineering demand parameter EDP). Experimental data is being used to provide dynamic characterization of the supporting bench system and response information regarding the equipment-bench interface.

[Full Report]

Roy A. Imbsen, Imbsen & Associates

Practitioner Critique of PEER Bridge Analysis Methodology—3332002
Roy Imbsen (I)

Critique the newly developed PEER methodology for seismic design of bridges using a portion of the I-880 Caltrans Viaduct located in Oakland, California, i.e., I-880 Testbed.

[Full Report]

Ufuk Ince, University of Washington

Analytic Models for PBEE Decisions—1252002
Jacqueline Meszaros (UW/F), Ufuk Ince (UW/F), Sonnier Francisco (UW/GS)

Translate our understanding of how mitigation decisions are made into useful analytical models (including financial and nonfinancial variables) for seismic hazard mitigation investment decisions.
[Full Report]

Boris Jeremic, University of California, Davis

3D Soil Simulation Models in OpenSees—2212002
Boris Jeremíc (UCD/F), Zhaohui Yang (UCD/PD), Kevin Murakoshi (UCD/US), Qing Liu (UCD/GS), Feng Xiong (UCD/PD)

The goal of this project is to develop computational tools for seismic analysis of soil-foundation-structure interaction (SFSI). In particular, three dimensional elastic-plastic material models, integration algorithms and coupled formulations are in development and are being used to assess the effects SFSI has on Humboldt Bay Bridge. To this end, a number of elastic-plastic material models have been developed and implemented into OpenSees. Moreover, a fully coupled solid fluid formulation has been developed and implemented into OpenSees as well and is currently being validated.
[Full Report]

I-880 Testbed Simulation—3252002
Sashi Kunnath (UCD/F), Boris Jeremíc (UCD/F), Anna von Felten (UCD/GS), Keith Bauer (UCD/GS), Jinxiu Liao (UCD/GS), Feng Xiong (UCD/GS)

The primary objective of the project is to apply evolving PEER performance-based earthquake engineering methodology to evaluate the seismic response of a section of the I-880 viaduct. A major component of the methodology involves the estimation of engineering demand parameters (EDP) for a given hazard level which is quantified by means of an intensity measure (IM). An accurate representation of EDPs for the I-880 testbed requires the development of adequate and reliable simulation models of the target system. The development of an appropriate computer model incorporating all critical elements of the system including soil-foundation interaction is one of the goals of this project. Another goal of the project is to investigate sensitivity of material and modeling parameters in estimating EDP|IM. A related objective of the project is to provide input to the development and validation of OpenSees.

[Full Report]

Mark A. Ketchum, OPAC Consulting Engineers

Influence of Design Ground Motion Level on Highway Bridge Costs—Lifelines 6D01
Mark Ketchum (OPAC/I), Vivian Chang (OPAC/I), James Scheld (OPAC/I), Kwong Cheng (OPAC/I), Francis Drouillard (OPAC/I), Tom Shantz (Caltrans/I), Fadel Alemeddine (Caltrans/I)

The project proposes to quantify, in percentage terms, the cost impact of raising or lowering levels of design ground motion for new highway bridges. The nature of the cost curve may be influenced by many variables, including site-specific issues as well as bridge-type-specific issues. Its basic features, the nature of design constraints that define the cusps, and the relative economy of various bridge types at differing levels of design ground motions are immediately achievable objectives of this project. The project focuses on bridge types used for ramps, interchanges, and grade separations, which account for the majority of bridge construction costs in California.

[Full Report]

Steven L. Kramer, University of Washington

Effects of Geotechnical Uncertainties on EDPs—2352002
Steve Kramer (UW/F), Pedro Arduino (UW/F), Sarah Paulsen (UW/GS)

The goal of the proposed project is to systematically investigate the effects of uncertainty in geotechnical parameters on uncertainty in engineering demand parameters (EDPs). The work will be accomplished in a hierarchical manner, beginning with relatively simple geotechnical models and site conditions and progressing to more complicated models and conditions. The EDPs will be simple, and selected to be consistent with those being used in PEER structural engineering investigations. The results will provide insights into the level of uncertainty inherent in ground motion predictions with the tools most commonly used in contemporary geotechnical engineering practice, and with more advanced tools developed by PEER.

[Full Report]

Helmut Krawinkler, Stanford University (Thrust Area 3 Leader)

Engineering Assessment Methodology—3192002
Helmut Krawinkler (Stanford/F), Ricardo Medina (Stan/GS), Luis Ibarra Olivas (Stan/GS), Farzin Zareian (Stan/GS), Christoph Adam (Stan/PD)

The objective is to develop quantitative information and simplified procedures that permit approximate performance assessment by means of commonly employed engineering analysis methods. Performance is expressed in terms of confidence levels and mean annual frequencies of exceedance of selected performance parameters (collapse, story drifts, inelastic deformations, and selected damage measures). The expected outcomes of the research are information and procedures that will assist the engineering profession in carrying out performance assessment with currently available tools and with tools that are under development by the research community.

[Full Report]

Sashi Kunnath, University of California, Davis

I-880 Testbed Simulation—3252002
Sashi Kunnath (UCD/F), Boris Jeremíc (UCD/F), Anna von Felten (UCD/GS), Keith Bauer (UCD/GS), Jinxiu Liao (UCD/GS), Feng Xiong (UCD/GS)

The primary objective of the project is to apply evolving PEER performance-based earthquake engineering methodology to evaluate the seismic response of a section of the I-880 viaduct. A major component of the methodology involves the estimation of engineering demand parameters (EDP) for a given hazard level which is quantified by means of an intensity measure (IM). An accurate representation of EDPs for the I-880 testbed requires the development of adequate and reliable simulation models of the target system. The development of an appropriate computer model incorporating all critical elements of the system including soil-foundation interaction is one of the goals of this project. Another goal of the project is to investigate sensitivity of material and modeling parameters in estimating EDP|IM. A related objective of the project is to provide input to the development and validation of OpenSees.

[Full Report]

Bruce Kutter, University of California, Davis

Performance of Shallow Foundations—2262002
Bruce Kutter (UCD/F), Sivapalan Gajan (UCD/GS), Justin Phalen (UCD/GS), Peggy Walgenbach (UCD/O)

The nonlinearity of the soil and the interaction between the soil and foundation is shown to cause the building's stiffness and period to change to varying degrees. On the one hand, the nonlinearity of the soil may act as an energy dissipation mechanism, potentially reducing demands exerted on the structural components of the building. This associated nonlinearity, however, may result in permanent deformations (rotation or settlement) that cause damage to the building. The goal of this research is to further the understanding of soil-foundation-structure interaction with regards to seismic response.

[Full Report]

Kincho Law, Stanford University

Data Management for OpenSees Simulations—4152002
Kincho Law (Stanford/F), Jun Peng (Stanford/GS)

This research project, in collaboration with researchers at PEER center, aims to develop a software platform that assists the application of performance-based earthquake engineering (PBEE) assessment and design methodologies. The project focuses on supporting testbed applications, data and project management, and archival capabilities. The objective is to provide a persistent storage for the analysis results for OpenSees, to support project management, and to archive testbed projects data. The data management system is to be designed to manage information related to seismic inputs, simulation models, and simulation results so that performance metric, demand parameters, and damage measures can be derived from the simulation results. Finally, an easy-to-use user interface is to be developed so that data can be queried via a web interface or an application program such as MATLAB.

[Full Report]

Dawn Lehman, University of Washington

Validation of Simulation and Performance Models of RC Joints—5352002
Dawn Lehman (UW/F), John Stanton (UW/F), George Gimas (UW/US), Meredith Anderson (UW/GS)

The goals of the study are to develop practical simulation and performance models for beam-column joints that lack transverse reinforcement. The specific objectives, which constitute the research tasks and deliverables, include:

  1. Development of simple simulation tools for immediate use by the profession. (Task 1)
  2. Validation of more advanced simulation tools. (Task 2)
  3. Development of performance models appropriate for each type of simulation model, including acceptance criteria. (Task 3)
  4. Development of guidelines for the use of each pair of simulation and performance models. (Task 4)

[Full Report]

Laura Lowes, University of Washington

Van Nuys Testbed Simulation—3272002
Laura Lowes (UW/F), Chaitanya Paspuleti (UW/GS), Nilanjan Mitra (UW/GS)

The primary objective of the proposed research effort is the development of state-of-the-art 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 non-structural damage and economic loss, and
  3. predict the impact of the FEMA 356 retrofit scheme on damage and loss.

[Full Report]

Nicolas Luco, AIR Worldwide Corporation

Parameterization of Non-Stationary Acceleration Time Histories—Lifelines 1G00
Paolo Bazzurro (AIR/I), Nicolas Luco (AIR/I), Norm Abrahamson (PG&E/I), Brian Chiou (Caltrans/I), Allin Cornell (Stanford/F), Joe Maffei (R&C/I), Maury Power (Geomatrix/I)

The project is structured into two phases:

Phase I: Investigate whether "non-stationary" characteristics of seismograms, in addition to more conventional ground motion intensity measures (e.g., spectral values), can improve the accuracy in the prediction of structural seismic performance.

Phase II: Three tasks

[Full Report]

Joseph R. Maffei, Rutherford & Chekene

Parameterization of Non-Stationary Acceleration Time Histories—Lifelines 1G00
Paolo Bazzurro (AIR/I), Nicolas Luco (AIR/I), Norm Abrahamson (PG&E/I), Brian Chiou (Caltrans/I), Allin Cornell (Stanford/F), Joseph Maffei (R&C/I), Maury Power (Geomatrix/I)

The project is structured into two phases:

Phase I: Investigate whether "non-stationary" characteristics of seismograms, in addition to more conventional ground motion intensity measures (e.g., spectral values), can improve the accuracy in the prediction of structural seismic performance.

Phase II: Three tasks

[Full Report]

Advanced Seismic Assessment Guidelines—Lifelines 507
Allin Cornell (Stanford/F), Charles Menun (Stanford, F), Paolo Bazzurro (AIR/I), Maziar Matahari (Stanford/GS), Gee Liek Yeo (Stanford/GS), Joe Maffei (R&C/I)

The primary objective of this two-phase project is the development of a new level of guidelines for the assessment of existing buildings. The scope is limited to typical PG&E 1-3 story buildings often of older and mixed construction. The limit states considered are those of direct electrical-system-reliability interest, e.g., collapse and (red or yellow) tagging, the latter because of their operability implications. An advanced state-of-practice engineering is employed, e.g., the structural engineer will provide a nonlinear (NL) static pushover analysis (SPO). In keeping with sponsor-stated needs and recent SAC and PEER developments, the guidelines will incorporate both aleatory and epistemic uncertainty measures, and the guidelines’ output products will include limit-state “fragility curves”, i.e., curves of the probability of limit state given ground motion intensity (IM) level, that reflect these various uncertainties. The first-year objective has been a “beta-version” of these guidelines, using results of only the first year’s research and default methods and parameter values where necessary. Nonetheless this first-year version is “operational”, i.e., up to or beyond current practice in all respects, such that it is being tested by two top-level structural engineering firms in the second year.

[Full Report]

Test Applications of Advanced Seismic Assessment Guidelines—Lifelines 508
Joe Maffei (R&C/I), Dayna Mohr (R&C/I)

Advanced seismic assessment guidelines were developed by Stanford University (C. Allin Cornell, Paolo Bazzurro, Charles Menun, Maziar Motahari) as part of the PEER Lifelines Program, Building Vulnerability Studies (Project Task Number 507). Predicting the post-earthquake functionality of utility structures is a crucial step in evaluating the likelihood of the electric distribution network being able to provide gas and electricity to its customers. The final product of the guidelines is a set of fragility curves for structural limit states directly related to post-earthquake building occupancy status, namely green, yellow, or red tagging.
This project proposal is for a practicing Structural Engineer to apply these guidelines to utility type buildings.

[Full Report]

Stephen A. Mahin, University of California, Berkeley

Integration of OpenSees and NEES—4192002
Steve Mahin (UCB/F), Andreas Schellenberg (UCB/GS)

OpenSees provides a rich set of highly capable modules that support the nonlinear static and dynamic analysis of complex structural systems. Its advanced, object-oriented, open-source format makes it ideally suited for hybrid simulation, where some portions of a structure are modeled numerically, while others are physically tested. Many of the advanced hybrid simulation applications being considered as part of NSF’s George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) and elsewhere require high performance analysis capabilities. Next-generation hybrid simulation techniques require an analysis framework able not only to carry out complex structural computations quickly, but also one that is able to operate transparently within a complex, real time computing and control environment. As such, OpenSees provides an ideal computing framework, and its capabilities will substantially advance the development of hybrid simulation as an effective tool for use by the earthquake engineering community.

[Full Report]

Bridge Bent Shaking Table Validation Tests—5272002
Steve Mahin (UCB/F), Andreas Espinoza (UCB/GS), Mahmoud Hachem (UCB/GS), Eric Anderson (UCB/GS), Peter Symonds (UCB/US)

The goal of this project is to conduct a test on a simple reinforced concrete model bridge system, resulting in development of validation data on nonlinear response, component yielding/damage, and internal force redistribution during ductile response.

[Full Report]

Assessment and Design of Enhanced Performance Bridge Systems—5342002
Steve Mahin (UCB/F), Junichi Sakai (UCB/PD)

The overall goal of this study is to examine and assess various design concepts for enhancing the seismic performance of new bridge structures of the type being considered by PEER. Promising design details will be assessed though dynamic shaking table tests as well as through more extensive nonlinear dynamic analyses using the OpenSees computational platform. In particular, the potential for reducing residual displacements of bridges following severe earthquakes will be examined through the use of special plastic hinge regions containing combinations of unbonded, prestressed and mild reinforcement. Other design approaches utilizing high performance concrete, foundation details that permit rocking behavior, or other enhancements will be examined in concert with others working within the PEER Center. The PEER PBEE methodology will be utilized to quantify the benefits of these enhanced systems in comparison with conventional bridge construction in use today. The goal of this project would be to demonstrate the value of the PEER methodology for a specific application, and thereby to accelerate the adoption of new bridge design technologies into practice.

[Full Report]

Nicos Makris, University of California, Berkeley

Performance Characteristics of Building Contents—5302002
Nicos Makris (UCB/F), Dimitrios Konstantinidis (UCB/GS), Margarita Constantinides (UCB/GS)

In this project experimental and analytical studies are underway to examine the seismic vulnerability of free standing and anchored equipment located within buildings with several floor levels. The equipment of interest are low-temperature refrigerators, freezers, incubators and other heavy equipment of the Life Science Addition (LSA) building on the UC Berkeley campus.

The dynamic behavior of either free-standing or anchored equipment is very sensitive to the characteristics of the base input (mainly acceleration amplitudes and frequency content), the frictional characteristics of the equipment-base interface, the restrainer strength and ductility and the structural rigidity of the equipment.

[Full Report]

Geoffrey Martin, University of Southern California

Performance of Shallow Foundations—2272002
Geoffrey Martin (USC/F), Tara Hutchinson (UCI/F), Chad Harden (UCI/GS), Barbara Chang (UCI/GS)

The goals of PEER researchers (at UCD, USC, and UCI) studying the nonlinear behavior of shallow building foundations are to develop and test procedures to account for this nonlinearity in performance-based design. So far, it is established that soil yielding beneath foundations can be a very effective energy dissipation mechanism. However, foundation yielding may lead to excessive permanent deformations. The primary goal of the research at UCD (Kutter) is to produce archived test data at prototype stress levels. Collaborating researchers at UCI (Hutchinson) and USC (Martin) are using the experimental data provided by UCD and by other sources primarily for performing numerical analysis using OpenSees.

[Full Report]

Peter May, University of Washington (Thrust Area 1 Co-Leader)

Regulatory System Implications of Performance-Based Regulation—1232002
Peter May (UW/F), Chris Koski (UW/GS)

Key societal issues for PBEE are the need for and the ability of the building regulatory system to adjust to changes brought about by the performance-based approach. Although code-writers are advancing application of PBEE concepts, the question remains how well those who implement codes – state agencies, local building code authorities, building officials, and inspectors – are able to adapt to these provisions.
[Full Report]

Jack Meszaros, University of Washington-Bothell

Analytic Models for PBEE Decisions—1252002
Jacqueline Meszaros (UW/F), Ufuk Ince (UW/F), Sonnier Francisco (UW/GS)

Translate our understanding of how mitigation decisions are made into useful analytical models (including financial and nonfinancial variables) for seismic hazard mitigation investment decisions.
[Full Report]

Eduardo Miranda, Stanford University

Building Loss Assessment—1182002
Eduardo Miranda (Stanford/F), Hesameddin Aslani (Stanford/GS)

The main objective in this project is to develop a methodology to estimate the economic losses in buildings from earthquakes. Instead of having discrete qualitative performance levels of a structure, this project aims at describing the seismic performance of the building in a continuum way, and more specifically in terms of dollar losses. In this project, emphasis is on losses associated with damage to structural components. This project is being conducted in connection with the seven-story reinforced concrete building PEER testbed structure. Loss estimation associated to non-structural components is being conducted in another project (Project # 5242002).

[Full Report]

Damage Assessment of Building Nonstructural Components—5242002
Eduardo Miranda (Stanford/F), Shahram Taghavi (Stanford/GS)

The objective of this study is to develop information and procedures to estimate the seismic performance of nonstructural components. This involves:

  1. the estimation of Engineering Demand Parameters (EDP) that are relevant to nonstructural components, which usually involve additional information to that required to estimate the performance of structural components;
  2. the development of fragility functions that enable the estimation of the probability of being in different damage states as a function of EDPs;
  3. the development of loss functions that permit the estimation of economic losses as a function of the damage state. This project is being conducted in connection with the seven-story reinforced concrete building PEER testbed structure. Loss estimation associated to structural components is being conducted in another project (Project # 1182002).

[Full Report]

Jack Moehle, University of California, Berkeley (PEER Director)

International Workshop on Performance-Based Earthquake Engineering—3162002
Jack Moehle (UCB/F)

The goal of this project is to enhance at an international level the exchange of the latest research and professional practice information on performance-based earthquake engineering.

[Full Report]

Tri-Center Initiative—3342002
Jack Moehle (UCB/F)

The goal is to enhance PEER research in geographically distributed networks by strategic planning and collaboration with other earthquake centers.

[Full Report]

RC Frame Validation Tests—5252002
Jack Moehle (UCB/F), Yoon Bong Shin (UCB/GS), Wassim Michael Ghannoum (UCB/GS), Tony Yang (UCB/GS), Jeffrey Liu (UCB/PD)

The goal of this project is to develop validation data and nonlinear models for nonlinear response, component failure mechanisms, and internal force redistribution as collapse occurs in a building frame representative of older concrete construction.

[Full Report]

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