Statistical inverse analysis based on genetic algorithm and principal component analysis: Applications to excavation problems and pressuremeter tests
Résumé
This study concerns the identification of constitutive models from geotechnical measurements by inverse analysis. Soil parameters are identified from measured horizontal displacements of sheet pile walls and from a measured pressuremeter curve. An optimization method based on a genetic algorithm (GA) and a principal component analysis (PCA), developed and tested on synthetic data in a previous paper, is applied. These applications show that the conclusions deduced from synthetic problems can be extrapolated to real problems. The GA is a robust optimization method that is able to deal with the non-uniqueness of the solution in identifying a set of solutions for a given uncertainty on the measurements. This set is then characterized by a PCA that gives a first-order approximation of the solution as an ellipsoid. When the solution set is not too curved in the research space, this ellipsoid characterizes the soil properties considering the measured data and the tolerate margins for the response of the numerical model. Besides, optimizations from different measurements provide solution sets with a common area in the research space. This intersection gives a more relevant and accurate identification of parameters. Finally, we show that these identified parameters permit to reproduce geotechnical measurements not used in the identification process. © 2009 John Wiley & Sons, Ltd.
Mots clés
First-order approximations
Geotechnical measurement
Horizontal displacements
Identification process
Identified parameter
Measured data
Nonuniqueness
Numerical models
Optimization method
Pressuremeter test
Pressuremeter tests
Pressuremeters
Real problems
Robust optimization method
Sheet pile wall
Soil parameter identification
Soil parameters
Soil property
Solution set
Synthetic data
Synthetic problem
Genetic algorithms
Geologic models
Inverse problems
Parameter estimation
Soil testing
Soils
Statistical tests
excavation
genetic algorithm
identification method
inverse analysis
numerical model
optimization
parameterization
pressuremeter
principal component analysis
uncertainty analysis
underground construction