ASCE-41 and FEMA-351 Evaluation of E-Defense Collapse Test

2009 ◽  
Vol 25 (4) ◽  
pp. 927-953 ◽  
Author(s):  
Bruce F. Maison ◽  
Kazuhiko Kasai ◽  
Gregory Deierlein

A welded steel moment-frame building is used to assess performance-based engineering guidelines. The full-scale four-story building was shaken to collapse on the E-Defense shake table in Japan. The collapse mode was a side-sway mechanism in the first story, which occurred in spite of a strong-column and weak-beam design. Computer analyses were conducted to simulate the building response during the experiment. The building was then evaluated using the Seismic Rehabilitation of Existing Buildings (ASCE-41) and Seismic Evaluation and Upgrade Criteria for Existing Welded Steel Moment-Frame Buildings (FEMA-351) for the collapse prevention performance level via linear and nonlinear procedures. The guidelines had mixed results regarding the characterization of collapse, and no single approach was superior. They mostly erred on the safe side by predicting collapse at shaking intensities less than that in the experiment. Recommendations are made for guideline improvements.

2003 ◽  
Vol 19 (2) ◽  
pp. 365-384 ◽  
Author(s):  
Charles A. Kircher

This paper describes procedures that may be used by experienced structural engineers to develop earthquake damage and related loss functions for welded steel moment-frame (WSMF) buildings. The damage and loss functions are based on and compatible with the loss estimation methods of HAZUS, a technology developed by Federal Emergency Management Agency (FEMA) for assessing regional impacts of earthquakes. The loss estimation procedures were developed by the SAC Steel Program as described in SAC Joint Venture Topical Report SAC/BD-99/13. These procedures form the basis for Appendix B of FEMA-351, Recommended Seismic Evaluation and Upgrade Criteria for Existing Welded Steel Moment-Frame Buildings. The procedures for developing damage and loss functions for WSMF building response are general in nature and applicable to WSMF buildings designed to different seismic criteria and having different connection details. Default values of damage and loss function parameters are provided for typical 3-story, 9-story, and 20-story WSMF buildings, designed for Los Angeles, Seattle, or Boston seismic criteria and having pre-Northridge, post-Northridge, or damaged pre-Northridge connection conditions.


2003 ◽  
Vol 19 (2) ◽  
pp. 317-334 ◽  
Author(s):  
John D. Hooper

In July 2000, the SAC Joint Venture (a joint venture of the Structural Engineers Association of California, the Applied Technology Council, and California Universities for Research in Earthquake Engineering) prepared a series of recommendations regarding welded steel moment-frame design, evaluation, and upgrade procedures. FEMA-351, Recommended Seismic Evaluation and Upgrade Criteria for Existing Welded Steel Moment-Frame Buildings, was developed to evaluate the probable performance of existing steel moment-frame buildings in future earthquakes and to provide guidance or upgrading these buildings. The procedures introduced in FEMA-351 allow the determination of the level of confidence a structure will be able to achieve based on a specified performance objective, using simplified analytical methods. Simplified procedures for estimating the probable post-earthquake repair costs and nonstructural damage, based on the losses incurred in the 1994 Northridge earthquake, are presented as well. This paper provides a brief chapter-by-chapter overview of the information contained in FEMA-351 and emphasizes the performance evaluation procedures by stepping through the process using an example building.


2004 ◽  
Vol 20 (3) ◽  
pp. 951-973 ◽  
Author(s):  
Bruce F. Maison ◽  
Tom H. Hale

The two-story welded steel moment-frame (WSMF) essential services building had columns severed by the 1994 Northridge earthquake. Two of eight columns suffered fracture across both flanges and panel zones in the WSMFs oriented in the north-south direction. Building and connection damage are described; computer models of the building are formulated and used in a damage correlation exercise that aids in damage interpretation; and a calibrated model is used as the basis of special studies. Factors contributing to the severed columns appear to be column-steel low-fracture toughness, panel zone detailing, and panel-zone shear yielding. Using FEMA-351 guidelines, the as-built as well as the Northridge-damaged structure pass the global collapse prevention drift criterion and fail the local collapse prevention drift criterion. The results provide insight regarding the seismic safety of buildings having similar conditions.


2010 ◽  
Vol 452-453 ◽  
pp. 469-472
Author(s):  
Hong Bo Liu ◽  
Long Jun Xu ◽  
Shuang Li ◽  
Yong Song Shao

Following the 1994 Northridge earthquake, widespread damages were discovered in welded steel moment frame buildings. In order to accurately simulate the typical seismic damage of welded steel moment frame structures, a new simplified model is proposed for performing seismic evaluation of welded steel moment frame structures. In this model, the slabs effect is considered, as well as the effects of the slip between slabs and steel beams, deformation of panel zone and connection fractures. Fracture toughness demands were evaluated in terms of the mode I stress intensity factor. The model was employed in simulation of seismic damage of Blue Cross Building which experienced fractured connections in the Northridge earthquake. It indicates that the model can accurately predict the earthquake response of welded steel moment frame structures and estimate the level of damage. The approach proposed in this paper has important meaning to the research on seismic damage of steel frame which may experience fractured connections.


2003 ◽  
Vol 19 (2) ◽  
pp. 335-364 ◽  
Author(s):  
David Bonowitz ◽  
Bruce F. Maison

FEMA-351, Recommended Seismic Evaluation and Upgrade Criteria for Existing Welded Steel Moment-Frame Buildings, offers two methods for estimating seismic losses in pre-Northridge WSMFs: detailed and rapid. The rapid method uses empirical relationships between seismic demand parameters and either damage levels or repair costs. The relationships are based on actual damage data collected after the 1994 Northridge earthquake. This paper summarizes the Northridge data, explains the FEMA-351 rapid method loss functions, and comments on the nature of the damage data and its application to loss estimation. Use of the loss functions can be enhanced by understanding their inherent assumptions and uncertainties and by considering how the underlying data was collected and interpreted in the years following the 1994 earthquake.


2003 ◽  
Vol 19 (2) ◽  
pp. 399-414
Author(s):  
Maryann T. Phipps

In the wake of a potentially damaging earthquake, every affected welded steel moment-frame building should be assessed to determine whether it poses a safety risk. A straightforward, multi-step process has been developed to streamline this formidable task. This paper provides an overview of this procedure and repair techniques as published in FEMA-352, Recommended Post-earthquake Evaluation and Repair Criteria for Welded Steel Moment-Frame Buildings. The evaluation procedure, developed as part of the SAC Steel Project, begins with screening to rapidly identify those buildings unlikely to have been damaged. Subsequent steps help identify buildings that have sustained sufficient structural damage to compromise future performance and to determine appropriate actions regarding building occupancy and repair.


2006 ◽  
Vol 22 (4) ◽  
pp. 1081-1101 ◽  
Author(s):  
Bruce F. Maison ◽  
Kazuhiko Kasai ◽  
Yoji Ooki

Seismic behaviors of a five-story welded steel moment-frame (WSMF) office building in Kobe, Japan, and a six-story WSMF office building in Northridge, California, are compared. Both experienced earthquake damage (1995 Kobe and 1994 Northridge earthquakes, respectively). Computer models of the buildings are formulated, having the ability to simulate damage in terms of fractured moment connections. Analyses are conducted to assess building response during the earthquakes. The calibrated models are then analyzed using a suite of earthquake records to compare building performance under consistent demands. The Kobe building is found to be more rugged than the Northridge building. Analysis suggests it would experience much less damage than the Northridge building from shaking equivalent to 2,500-year earthquake for a generic Los Angeles site. Superior performance of the Kobe building is attributed to its relatively greater stiffness and strength. The results provide insight into the difference in seismic fragility expected for this class of mid-rise WSMF buildings in Japan and the United States.


2003 ◽  
Vol 19 (2) ◽  
pp. 309-315
Author(s):  
Robert E. Shaw

FEMA-353, Recommended Specifications and Quality Assurance Guidelines for Steel Moment-Frame Construction for Seismic Applications, contains numerous provisions related to the materials, details, quality, and inspection of steel moment-frame buildings in seismic regions. These provisions continue to evolve as industry standards and practices are reviewed, modified, and adopted to meet the need for good seismic performance. Those writing project specifications must remain current with new industry developments and standards.


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