Abstract
This study proposes a back-analysis method in which shear wave velocity and damping coefficient of soil deposit are back-calculated from the vertical accelerations measured in a dropping weight vibration test. In the back-analysis, comparison in frequency domain is made between the vertical acceleration monitored at ground surface and the ones calculated by finite element analysis in time domain. The problem is formulated as an optimization problem to find the dynamic soil parameters which minimize the sum of squares of difference between measured and calculated Fourier spectrum. The method is applied to some actual soil deposits and the result is discussed. When soil deposit is not so complicated, it is shown that the back-analyzed soil parameters duplicate precisely the actual accelerations, and that the back-analyzed soil parameters agrees fairly well with the soil parameters obtained from a conventional dynamic triaxial test.
