Earthquake Loss Estimation Methods for Welded Steel Moment-Frame Buildings

2003 ◽  
Vol 19 (2) ◽  
pp. 365-384 ◽  
Author(s):  
Charles A. Kircher
Keyword(s):  
Los Angeles ◽  
Joint Venture ◽  
Loss Estimation ◽  
Loss Functions ◽  
Estimation Methods ◽  
Seismic Evaluation ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Welded Steel ◽  
Frame Buildings

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.

Evaluating and Upgrading Welded Steel Moment-Frame Buildings Using FEMA-351

2003 ◽  
Vol 19 (2) ◽  
pp. 317-334 ◽  
Author(s):  
John D. Hooper
Keyword(s):  
Earthquake Engineering ◽  
Joint Venture ◽  
Northridge Earthquake ◽  
Seismic Evaluation ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Welded Steel ◽  
Frame Design ◽  
Frame Buildings ◽  
Simplified Procedures

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.

Northridge Welded Steel Moment-Frame Damage Data and Its Use for Rapid Loss Estimation

2003 ◽  
Vol 19 (2) ◽  
pp. 335-364 ◽  
Author(s):  
David Bonowitz ◽  
Bruce F. Maison
Keyword(s):  
Rapid Method ◽  
Loss Estimation ◽  
Loss Functions ◽  
Northridge Earthquake ◽  
Seismic Evaluation ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Welded Steel ◽  
Repair Costs ◽  
Damage Data

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.

Relative Performance of Kobe and Northridge WSMF Buildings

2006 ◽  
Vol 22 (4) ◽  
pp. 1081-1101 ◽  
Author(s):  
Bruce F. Maison ◽  
Kazuhiko Kasai ◽  
Yoji Ooki
Keyword(s):  
Los Angeles ◽  
The United States ◽  
Office Building ◽  
Superior Performance ◽  
Moment Frame ◽  
Moment Connections ◽  
Steel Moment Frame ◽  
Welded Steel ◽  
The Difference ◽  
Seismic Behaviors

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.

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
Keyword(s):  
Seismic Evaluation ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Welded Steel ◽  
Seismic Rehabilitation ◽  
Frame Building ◽  
Weak Beam ◽  
Beam Design ◽  
Safe Side ◽  
Computer Analyses

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.

scholarly journals Performance of Two 18-Story Steel Moment-Frame Buildings in Southern California during Two Large Simulated San Andreas Earthquakes

2006 ◽  
Vol 22 (4) ◽  
pp. 1035-1061 ◽  
Author(s):  
Swaminathan Krishnan ◽  
Chen Ji ◽  
Dimitri Komatitsch ◽  
Jeroen Tromp
Keyword(s):  
Los Angeles ◽  
Southern California ◽  
Building Code ◽  
Los Angeles Basin ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Existing Building ◽  
San Andreas ◽  
Frame Buildings ◽  
San Fernando

Using state-of-the-art computational tools in seismology and structural engineering, validated using data from the Mw=6.7 January 1994 Northridge earthquake, we determine the damage to two 18-story steel moment-frame buildings, one existing and one new, located in southern California due to ground motions from two hypothetical magnitude 7.9 earthquakes on the San Andreas Fault. The new building has the same configuration as the existing building but has been redesigned to current building code standards. Two cases are considered: rupture initiating at Parkfield and propagating from north to south, and rupture propagating from south to north and terminating at Parkfield. Severe damage occurs in these buildings at many locations in the region in the north-to-south rupture scenario. Peak velocities of 1 m.s−1 and 2 m.s−1 occur in the Los Angeles Basin and San Fernando Valley, respectively, while the corresponding peak displacements are about 1 m and 2 m, respectively. Peak interstory drifts in the two buildings exceed 0.10 and 0.06 in many areas of the San Fernando Valley and the Los Angeles Basin, respectively. The redesigned building performs significantly better than the existing building; however, its improved design based on the 1997 Uniform Building Code is still not adequate to prevent serious damage. The results from the south-to-north scenario are not as alarming, although damage is serious enough to cause significant business interruption and compromise life safety.

Seismic Design Guidelines and Provisions for Steel-Framed Buildings: FEMA 267/267A and 1997 AISC Seismic Provisions

2000 ◽  
Vol 16 (1) ◽  
pp. 179-203
Author(s):  
James O. Malley ◽  
Charles J. Carter ◽  
C. Mark Saunders
Keyword(s):  
Wide Spectrum ◽  
Steel Structures ◽  
Design Guidelines ◽  
Northridge Earthquake ◽  
Earthquake Hazards ◽  
Steel Buildings ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Welded Steel ◽  
Frame Buildings

One of the important surprises of the Northridge earthquake of January 17, 1994, was the widespread and unanticipated brittle fracture of welded steel beam-to-column connections. Although no casualties or collapses occurred during the Northridge earthquake as a result of these connection failures, and many WSMF buildings were not damaged at all, a wide spectrum of brittle connection damage did occur, ranging from minor cracking to completely severed columns. This paper summarizes two of the most important documents that have been developed in response to the damage suffered to steel moment frame buildings in the Northridge earthquake. The first, FEMA 267, Interim Guidelines: Evaluation, Repair, Modification and Design of Welded Steel Moment Frame Structures, was generated from studies undertaken as part of a project initiated by the U.S. Federal Emergency Management Agency (FEMA) to reduce the earthquake hazards posed by steel moment-resisting frame buildings. The second document addressed in this paper is the 1997 edition of the American Institute of Steel Construction (AISC) Seismic Provisions for Structural Steel Buildings (commonly referred to as the AISC Seismic Provisions) that incorporates the new information generated by the FEMA-sponsored project and other investigations on the seismic performance of steel structures, and has been adopted by reference into the 2000 International Building Code (IBC).

A Model of Steel Frame for Simulating Connection Fractures

2010 ◽  
Vol 452-453 ◽  
pp. 469-472
Author(s):  
Hong Bo Liu ◽  
Long Jun Xu ◽  
Shuang Li ◽  
Yong Song Shao
Keyword(s):  
Seismic Damage ◽  
Steel Frame ◽  
Frame Structures ◽  
Steel Beams ◽  
Northridge Earthquake ◽  
Seismic Evaluation ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Welded Steel ◽  
Panel Zone

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.

Sign in / Sign up

Export Citation Format

Share Document