Volume 24, Issue 4 (December 2001)
Simultaneous Measurement of Surface Wave Dispersion and Attenuation Curves
In existing surface wave test procedures, experimental dispersion and attenuation curves are determined separately (i.e., uncoupled) using different source-receiver configurations and different interpretation methods. A new procedure based on displacement transfer functions is proposed in which dispersion and attenuation data are derived simultaneously (i.e., coupled) from a single set of measurements using the same source-receiver array. The new approach is motivated by the recognition that in dissipative media, Rayleigh phase velocity and attenuation are not independent as a result of material dispersion. Therefore, a coupled analysis of dispersion and attenuation is a more robust, fundamentally correct approach. The new approach is also more consistent with coupled inversion techniques to obtain the shear wave velocity and shear damping ratio profiles. The proposed approach is illustrated using data measured at a site in Atlanta, Georgia.