Accession Number:

ADA014194

Title:

Digital Filters for Earthquake Site Studies.

Descriptive Note:

Final rept. Fy 1973-1974,

Corporate Author:

ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS

Personal Author(s):

Report Date:

1975-07-01

Pagination or Media Count:

41.0

Abstract:

The objective of this study was to develop a computerized technique for processing strong-motion accelerograms from earthquakes in order that earthquake vulnerability for existing structures can be more fully investigated through the use of simplified base excitations. Through filter theory, the Wiener normal equations were used to reduce accelerogram pairs to basic time histories called operators. This approach isolates the differences contained within accelerogram pairs from project sites at which the data were obtained. The operators are used with mathematical shocks such as half-sine pulses as inputs to produce simplified responses. Variations in the simplified responses are obtained by changing the durations of the half-sine or other hypothetical wave form inputs and using the same operator for each variation. Each family of responses is then studied to determine its sensitivity to these changes. As an example of this theory, data from an earthquake of magnitude 4.4 or - were used to construct operators that related free-field motions to those on the main and auxiliary dams at the Isabella Reservoir near Bakersfield, California. Based on the results of this study, it is concluded that use of this technique should enable structural engineers to assess earthquake vulnerability for existing structures more fully, and that this in turn could lead to improvements in furture designs.

Subject Categories:

  • Seismology
  • Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE