- Author
-
Carino, N. J.
- Title
- Performance of Buildings.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Department of the Interior, Reston, VA
- Report
-
NIST SP 778; ICCSSC TR11,
January 1990,
201 p.
- Distribution
- Available from Government Printing Office
- Book or Conf
- Performance of Structures During the Loma Prieta Earthquake of October 17, 1990,
Lew, H. S., Editors,
4/1-53 p.,
1990
- Keywords
-
earthquakes
|
building codes
|
fire safety
|
damage
|
bridges (structures)
|
highways
|
structural engineering
|
housing
|
geology
|
lifelines
|
seismic
|
specifications
|
viaducts
|
seismic design
- Abstract
- This chapter describes the performance of buildings within the Bay area and within the epicentral region. Because of the large area in which buildings were damaged, the inspections concentrated on those regions which experience a large amount of severe damage. As discussed in Chapter 3 the most serious damage was concentrated in areas of deep soil deposits. Most structures designed according to modern codes and standards performed well without structural damage. The majority of the damaged structures were either wood-framed dwellings or unreinforced masonry buildings which had not been strengthened to increase their seismic resistance. It should be noted that the Loma Prieta earthquake was not a severe test of buildings designed according to modern seismic criteria. Except for the epicentral region, peak ground accelerations were less than implied by modern building codes. Also, the duration of strong ground shaking was only 10 to 15 seconds. Thus, the favorable performance of the majority of modern buildings can not be used as evidence that current seismic design criteria are adequate. There were isolated failures in modern structures to which the team did not gain access. Detailed investigations of the circumstances associated with these failures can provide opportunities to improve design standards if it is found that the failures occurred where standards were met. The Loma Prieta earthquake also provided opportunities to evaluate the performance of the various seismic strengthening methods used within the affected region. The team observed many instances of successful strengthening measures, but there were also examples of unsuccessful measures. This chapter provides examples of the type of damage observed in the more severely affected regions. Probable failure mechanisms are discussed where possible, but no attempt is made to provide in-depth explanations of the underlying factors leading to the observed damage.