Earth Vibration Effects and Abatement for Military Facilities. Report 4. Ground Motion Transmission in Nonhomogeneous Soils.
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
Pagination or Media Count:
This report is the fourth in a series of reports dealing with the development of adequate methods for predicting ground motion resulting from known foundation motion and the establishment of reliable and economical methods for the solution of isolation and motion control problems posed by present and future Army requirements. The first report dealt with the selection of an adequate test site for experimentation, the second report dealt with calculating and measuring ground motions, and the third with analysis methods for surface sources of vibration. This report presents tabulated ground motion data taken during pilot experiments at the Eglin Field test site, and represents a very brief, qualitative, theoretical description of the general trends of the data accumulated. An attempt was made to interpret and describe the ground motion produced by a sinusoidal surface source at a ground site where the elastic properties were assumed to vary in a simple way with depth. The variation of the shear modulus with depth was determined in the field using a sinusoidal mechanical vibrator as a source. The compression modulus was determined as a function of depth by measuring the travel time of a P-wave between two geophones buried in the soil. The particle velocity in the ground surrounding the vibrator was measured and tabulated. Some of the data taken showed a considerable scatter, which may be due to subsurface inhomogeneities. The attenuation coefficients describing the decrease of vibration amplitude with radial distance were found to be frequency dependent. Author
- Soil Mechanics
- Civil Engineering
- Structural Engineering and Building Technology