Abstract:

There are some thorny problems such as uncertainty and instability solution produced by initial parameters when hierarchical optimization is applied to the viscoelastic cavern displacement in parameter inversion. A simple search method is used in the hierarchical optimization. The hierarchical pattern search is provided to solve these problems. A new method has some computing strategies based on least-square method, which can avoid iterative non-convergence when initial parameters are not optimally selected. Numerical results show that the hierarchical pattern search is nearly independent of the original value; and the method has high accuracy and validity for the viscoelastic cavern displacements of parameter inversion.

Key words: deformation monitoring of cavern, displacement back analysis, hierarchical optimization, pattern search