The purpose of this study is to investigate the propagation characteristics of the ground vibrations, to develop a prediction method of the attenuation characteristics of ground vibrations and to evaluate in-situ material damping ratio using the attenuation characteristics. To do this objects, a velocity transducer was calibrated in the laboratory over a wide frequency range, and field vibration measurements for various sources were performed using 3-component velocity-transducers assembled by the calibrated velocity transducers.
Generally, the attenuation of vibrations with distance is composed of two factors; geometrical damping and material damping. The geometrical damping of ground-vibrations are depends on the type and location of vibration sources. In thesis paper, the experimental study was conducted varying vibration sources including blasting, dynamic compaction, and train loading. Based on the test results, geometrical damping coefficients for each vibration sources were determined and frequency domain analysis showed that the high frequency energy dissipates more rapidly with distance than the low frequency energy. Finally, by subtracting the geometrical damping terms from the measured vibrations, in-situ measurement of material damping was performed and the measured damping values were compared with laboratory results determined by resonant column and torsional shear tests.
