抄録
This note proposes a numerical procedure in which the material parameters affecting soil dynamics are back-calculated from the acceleration response monitored in the field. By assuming the values of soil parameters, the acceleration response of the dynamical system is calculated by a finite element analysis in time domain. Because the direct comparison in time domain between the calculated and monitored accelerations has less reasonable meaning, the Fourier coefficients both of the accelerations are calculated. And the least squares method is applied to the Fourier coefficients corresponding to the calculated and observed quantities respectively. The formulated problem is successfully solved by mathematical programming technique. As the first phase of the research, the back-analyzed soil parameters are Young's modulus and damping coefficients by assuming the linear elastic behavior and the viscous damping of subsoil. The proposed procedure is applied to hypothetical case studies and its validity is verified. Subsequently the trial application of the procedure to actual case study is discussed which is concerned with the parameter estimation in soil deposit during an earthquake.
