# Accession Number:

## AD0849496

# Title:

## Feasibility of Predicting Airblast-Induced Ground Motions by the Statistical Analysis of Fourier Transforms Calculated from Measured Nuclear and Hest Time-Histories. Volume I.

# Descriptive Note:

## Technical rept. Dec 66-Nov 68,

# Corporate Author:

## BARRY WRIGHT CORP WATERTOWN MA BARRY CONTROLS DIV

# Personal Author(s):

# Report Date:

## 1969-02-01

# Pagination or Media Count:

## 93.0

# Abstract:

An investigation into the possibility of applying statistical analysis of the Fourier transforms of airblast-induced ground motion time-histories in order to predict the most probable spectral characteristics of the motions in terms of known independent variables is presented. The various analytical and empirical procedures used in the development of the prediction technique are discussed. A model Fourier transform equation is postulated to fit actual transforms calculated from measured nuclear and HEST test time-histories. Constants in the model transform equation are found so that the postulated spectra is made to fit the actual spectra for each measured time-history. A set of regression equations using peak overpressure, pressure-impulse, depth and seismic velocity as the independent variables are derived. A linear regression analysis is conducted to calculate new constants for the model spectra which have a mean squared error when compared to the constants fitted to each actual spectra. A statistical analysis of the model Fourier transform constants so calculated is conducted to determine the 95 percent confidence limits on the population mean, variance, and regression and correlation coefficients. Equations are derived for the vertical acceleration, velocity and displacement of the free-field airblast-induced ground motions based on the predicted most probable Fourier transform of the motions. Application of the transform and time-history equations is discussed in terms of an example. Author

# Descriptors:

- (*NUCLEAR EXPLOSIONS
- SHOCK WAVES)
- (*UNDERGROUND STRUCTURES
- EXPLOSION EFFECTS)
- (*EXPLOSION EFFECTS
- MATHEMATICAL PREDICTION)
- INTEGRAL TRANSFORMS
- HARMONIC ANALYSIS
- CORRELATION TECHNIQUES
- CONFIDENCE LIMITS
- ANALYSIS OF VARIANCE
- REGRESSION ANALYSIS
- POWER SPECTRA
- PRESSURE
- SEISMIC WAVES
- BLAST
- FEASIBILITY STUDIES
- MOTION

# Subject Categories:

- Structural Engineering and Building Technology