BACK ANALYSIS BY KALMAN FILTER-FINITE ELEMENTS AND A DETERMINATION OF OPTIMAL OBSERVED POINTS LOCATION

Abstract

This paper focuses on the following two topics: one is a new back analysis method using Kalman Filter-Finite Elements; the other is a determination of optimal location of observed nodal points for back analysis. A formulation is shown on Finite Element Method in conjunction with Kalman filter for two dimensional and plane strain problem, where Lamé's constants of non-homogeneous regions are solved. In the numerical procedure, the location of observed nodal points is determined taking into account the ‘sensitivity’ coefficients. These coefficients are defined as the derivatives of observed displacements by unknown parameters. The role and the meaning of ‘sensitivity’ coefficients in the Kalman Filter-Finite Elements are also discussed. The numerical performances for various problems in the field of geomechanics are described, and the applicability of the above procedure to some back analysis problems is examined on the comparison with the results by another algorithms.