Abstract
A method is proposed for the optimization of a configuration of displacementt measurement for back analysis in an 3-dimensional linear elastic problem involving tunnel excavation. A reliable estimation of a strain field obtained by back analysis depends on the quality of displacement measurements. Because displacement measurements must be done within a limited budget, an engineer needs to know the most effective and economical way of installing the measurement instruments such that the in-situ stresses are back-calculated to the highest accuracy that the instrumentation could achieve in a given condition. A simple optimization scheme proposed here enables the design of effective positioning of instruments in a general 3-dimensioinal problem which is illustrated by some examples in this manuscript.
