PEER Reports

PEER Reports

Experimental and Computational Evaluation of Reinforced Concrete Bridge Beam-Column Connections for Seismic Performance, PEER Report 2001-08

Clay J. Naito
Jack P. Moehle
Khalid M. Mosalam
2001

Proper design of reinforced concrete bridge beam-column connections is imperative for the behavior of the bridge structure. While in the past this area was overlooked, resulting in bridge structure damage and in some cases collapse, current methods have overcompensated for these shortcomings. The presented research shows that current joint design requirements in the state of California produce conservative designs (i.e., joints with excessive amounts of reinforcement). The joints in these systems are capable of supporting the intended flexural mechanism, but at the cost of constructability...

Ground Motion Evaluation Procedures for Performance-Based Design, PEER Report 2001-09

Jonathan P. Stewart
Shyh-Jeng Chiou
Jonathan D. Bray
Robert W. Graves
Paul G. Somerville
Norman A. Abrahamson
2001

The principal objective of the Pacific Earthquake Engineering Research Center (PEER) is to develop a sound, scientific ba sis for performance-based earthquake engineering. The development of this methodology includes three vital steps:

Evaluation of the distribution of ground motion intensity measures at a site, given certain seismological variables (i.e., fault characteristics, position of site relative to faults, etc.). Intensity measures may consist of traditional parameters such as spectral acceleration or duration, or newly defined parameters found to be useful for particular...

Amplification Factors for Spectral Acceleration in Active Regions, PEER Report 2001-10

Jonathan P. Stewart
Andrew H. Liu
Yoojoong Choi
Mehmet B. Baturay
2001

Empirical relationships are developed to predict amplification factors for 5% damped spectral acceleration (period range T = 0.01 – 5 s) as a function of site category. Amplification is evaluated by normalizing ground motion intensity measures from recordings by reference motions derived from modified attenuation relationships for active regions. The Abrahamson and Silva attenuation relationship for rock sites was used for the derivation of reference motions, with modifications to account for event terms and rupture directivity effects.

Strong motion sites are classified according...

Analytical and Experimental Study of Fiber-Reinforced Elastomeric Isolators, PEER Report 2001-11

James M. Kelly
Shakhzod M. Takhirov
2001

Theoretical and experimental analyses are carried out for the mechanical characteristics of multi-layer elastomeric isolation bearings where the reinforcing elements, normally steel plates, are replaced by a fiber reinforcement. The fiber-reinforced isolator, in contrast to the steel-reinforced isolator (which is assumed to be rigid both in extension and flexure), is assumed to be flexible in extension, but completely without flexure rigidity.

The influence of fiber flexibility on the mechanical properties of the fiber-reinforced isolator, such as the vertical and horizontal...

Development of Geotechnical Capabilities in OpenSees, PEER Report 2001-12

Boris Jeremic
2001

The PEER OpenSees project covers research on the “Next Generation Analytical Platform for Nonlinear Dynamic Analysis.” This report presents in some detail work performed for the “Development of Geotechnical Capabilities in OpenSees,” PEER project 2132000-3 started in May 2000. This report describes:

Development and implementation of the universal, template constitutive driver for OpenSees; Development of fully coupled, solid–fluid formulation; Development and implementation of visualization tools for solids in OpenSees; Examples of soil-foundation-structure interaction simulations; and...

Modeling Soil Liquefaction Hazards for Performance-Based Earthquake Engineering, PEER Report 2001-13

Steven L. Kramer
Ahmed-W. Elgamal
2001

The first widespread observations of damage attributed to liquefaction were made in the 1964 Niigata, Japan, and 1964 Alaska earthquakes. In numerous earthquakes since, liquefaction has been deemed responsible for significant damage to buildings and bridges. Liquefaction has been studied extensively over the past 35 years, and substantial advances have been made in understanding the development and effects of this phenomenon. These advances have led to a series of practical procedures for evaluating the potential for occurrence and for estimating its effects. These procedures, however, are...

Rocking Response of Equipment Anchored to a Base Foundation, PEER Report 2001-14

Nicos Makris
Cameron J. Black
2001

This study concentrates on the rocking response of rigid equipment supported on a foundation base. In most cases heavy electrical equipment is anchored on a concrete base with plan dimensions that are larger than the footprint of the equipment. In the event that the strength of the restrainers, Fu is sufficiently large and the ground acceleration is sufficiently strong, the equipment will engage its foundation in rocking motion. On the other hand, if the restrainers are too fragile they will fracture and eventually the equipment will rock atop its foundation base....

Damage to Bridges during the 2001 Nisqually Earthquake, PEER Report 2001-15

R. Tyler Ranf
Marc O. Eberhard
Michael P. Berry
2001

The 2001 Nisqually earthquake, which had a moment magnitude of 6.8, damaged at least 78 bridges in western Washington State. Reports of damage sustained by bridges during this earthquake were used to correlate the likelihood of damage with the following parameters: distance to the epicenter, estimated peak ground acceleration, estimated spectral acceleration at periods of 0.3 s, 1.0 s, and 3.0 s; year built; and type of bridge. This goal was accomplished by collecting reports of bridge damage from state and local agencies, and comparing them with the population of bridges listed in the...

Statistics of SDF-System Estimate of Roof Displacement for Pushover Analysis of Buildings, PEER Report 2001-16

Anil K. Chopra
Rakesh K. Goel
Chatpan Chintanapakdee
2001

Investigated in this report is the basic premise that the roof displacement of a multistory building can be determined from the deformation of an SDF system. For this purpose, the response of both systems is determined rigorously by nonlinear response history analysis, without introducing any of the approximations underlyi ng the simplified methods for estimating the deformation of an SDF system (see, e.g., FEMA-273 or ATC-40 guidelines). The statistics of the SDF-system estimate of roof displacement are presented for a variety of building frames and six SAC buildings subjected to ground...

Nonstructural Loss Estimation: The UC Berkeley Case Study, PEER Report 2002-01

Mary C. Comerio
John C. Stallmeyer
2002

Compared to structural systems, there is little basic research on the performance of nonstructural systems and building contents, and little empirical data on damage to specific systems, from past earthquakes. This report describes approaches to nonstructural hazards mitigation at the University of California, Berkeley, and focuses on design and cost estimates for anchoring the contents of laboratories. Research equipment is grouped into five categories: (1) tanks and cylinders, (2) unique equipment and experimental setups, (3) heavy equipment, (4) storage elements, and (5) benchtop items...