Identification of the Foundation Stiffness of Large Structure as an Inverse Problem

Abstract

When analyzing the strength of large structures, the stiffness of the foundation, on which the structure is placed, might significantly affect the numerical results. In this paper, a finite element approach to estimate the foundation stiffness as an inverse problem is proposed, where the target large structure is placed on the elastic foundation that are modeled as groups of one-dimensional spring elements in parallel. The magnitude of the spring constant that represents the foundation stiffness can exactly be calculated algebraically by use of the same number of measured surface deflections. In the numerical analyses, unknowns are the diagonal components in the global stiffness matrix that include the aforementioned spring constants. The validity and the accuracy of the proposed numerical method are verified by comparing the numerical results to the exact solutions for bending problems of a cantilever supported by a single spring element.