Seismic weaknesses of some residential wood framed buildings: confirmations from the 1994 Northridge earthquake

1995 ◽  
Vol 22 (2) ◽  
pp. 403-414 ◽  
Author(s):  
André Filiatrault ◽  
Chris K. A. Stieda

As part of the reconnaissance team of the Canadian Association for Earthquake Engineering (CAEE), the authors visited the epicentral region of the January 17, 1994, Northridge earthquake. This paper reviews the various potential weaknesses of some residential timber framed buildings. The damage observed during the Northridge earthquake as a result of these weaknesses is used to illustrate the need to introduce engineering concepts in the seismic design and retrofit of residential wood structures. Typical mitigation procedures to strengthen and increase the earthquake safety of wood buildings are discussed. Recognizing the close similarity between residential construction practice in Canada and the U.S., the information presented is topical for Canadian engineers, architects and owners. Key words: earthquake, seismic, timber, wood framed buildings.

2006 ◽  
Vol 22 (2) ◽  
pp. 555-563 ◽  
Author(s):  
Keith Porter ◽  
Kim Shoaf ◽  
Hope Seligson

The economic equivalent value of deaths and injuries in the 1994 Northridge earthquake has not previously been calculated, although number of injuries by category of treatment has. Using dollar-equivalent values for injuries accepted and used by the U.S. government for evaluating the cost-effectiveness of risk-mitigation efforts, the value of injuries in the 1994 Northridge earthquake is estimated to be $1.3 to 2.2 billion in 1994 (90% confidence bounds, equivalent to $1.8 to 2.9 billion in 2005). This is equivalent to 3–4% of the estimated $50 billion (in 1994) estimated direct capital losses and direct business interruption losses. If injuries in the 1994 Northridge earthquake are representative of injuries in future U.S. events, then the economic value of future earthquake injuries—the amount that the U.S. government would deem appropriate to expend to prevent all such injuries—is on the order of $200 million per year (in 2005 constant dollars). Of this figure, 96% is associated with nonfatal injuries, an issue overlooked by current experimental research. Given the apparently high cost of this type of loss, this appears to represent an important gap in the present earthquake research agenda.


1996 ◽  
Vol 86 (1B) ◽  
pp. S333-S349 ◽  
Author(s):  
J. P. Bardet ◽  
C. Davis

Abstract During the 1994 Northridge earthquake, the Van Norman Complex yielded an unprecedented number of recordings with high acceleration, in the close proximity of the fault rupture. These strong-motion recordings exhibited the pulses of the main event. One station recorded the largest velocity ever instrumentally recorded (177 cm/sec), resulting from a 0.86 g peak acceleration with a low frequency. Throughout the complex, the horizontal accelerations reached peak values ranging from 0.56 to 1.0 g, except for the complex center, where the peak acceleration did not exceed 0.43 g. The vertical acceleration reached maximum peak values comparable with those of the horizontal acceleration. The acceleration response spectra in the longitudinal and transverse directions were significantly different. Such a difference, which is not yet well documented in the field of geotechnical earthquake engineering, indicates that the amplitude and frequency content of the ground motion was directionally dependent in the Van Norman Complex.


1995 ◽  
Vol 22 (2) ◽  
pp. 361-377 ◽  
Author(s):  
Denis Mitchell ◽  
Ronald H. DeVall ◽  
Murat Saatcioglu ◽  
Robert Simpson ◽  
René Tinawi ◽  
...  

Observations on damage to concrete structures, due to the 1994 Northridge earthquake, are reported from a Canadian code perspective. Most of the damaged structures were older, nonductile, structures that do not conform to current design and detailing requirements. Concern is expressed about the seismic hazard of older Canadian structures having similar deficiencies. A significant number of parking structures suffered extensive damage and a number of precast concrete parking structures collapsed. Deficiencies in these structures include lack of proper diaphragm connections, a mix of gravity load columns with ductile framing, inappropriate number and distribution of shear walls, torsional effects caused by ramps, and the creation of short columns due to geometric features. This earthquake also demonstrated the deficiencies in connections of pre-1973 tilt-up structures. Key words: seismic design, earthquake, Northridge, structures, codes, concrete, precast concrete.


Nature ◽  
10.1038/37586 ◽  
1997 ◽  
Vol 390 (6660) ◽  
pp. 599-602 ◽  
Author(s):  
Edward H. Field ◽  
Paul A. Johnson ◽  
Igor A. Beresnev ◽  
Yuehua Zeng

1979 ◽  
Vol 6 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Paul Fazio ◽  
Kinh Ha ◽  
S. Chockalingam

The design of light-gage steel corrugated shear diaphragms is not yet covered by the structural codes of many countries, including Canada. The shear capacity of steel diaphragms may be predicted by various approaches currently available, namely, those proposed by: (1) the American Iron and Steel Institute; (2) the Manual of seismic design of buildings, published by the U.S. Departments of the Army, Navy, and Air Force; and (3) the recommendations outlined in the current British code. In this paper, a rational method is proposed and the application of all the above methods is illustrated with reference to a specific example. Finally, the shear strengths of many diaphragms are predicted by the new approach developed by the authors and the results are compared to test data.


1996 ◽  
Vol 11 (3) ◽  
pp. 172-179 ◽  
Author(s):  
Samuel J. Stratton ◽  
Virginia Price Hastings ◽  
Darlene Isbell ◽  
John Celentano ◽  
Miguel Ascarrunz ◽  
...  

AbstractIntroduction:This paper describes the 1994 Northridge earthquake experience of the local emergency medical services (EMS) agency. Discussed are means that should improve future local agency disaster responses.Methods:Data reported are descriptive and were collected from multiple independent sources, and can be reviewed publicly and confirmed. Validated data collected during the disaster by the Local EMS Agency also are reported.Results:The experience of the Los Angeles County EMS Agency was similar to that of earthquake disasters previously reported. Communication systems, water, food, shelter, sanitation means, power sources, and medical supplies were resources needed early in the disaster. Urban Search and Rescue Teams and Disaster Medical Assistance Teams were important elements in the response to the Northridge earthquake. The acute phase of the disaster ended within 48 to 72 hours and public health then became the predominant health-care issue. Locating community food and water supplies near shelters, providing transportation to medical care, and public-health visits to shelter locations helped prevent the development of long-term park encampments. An incident command system for the field, hospitals, and government responders was necessary for an organized response to the disaster.Conclusion:Disaster preparedness, multiple forms of reliable communication, rapid mobilization of resources, and knowledge of available state and federal resources are necessary for a disaster response by a local EMS agency.


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