[SSS15-P28] Bayesian optimization of fault-shape parameters using finite element analysis: parameter sets for strong slip partitioning
Keywords:Active Fault, Finite Element Method, Bayesian Optimization, Slip Partitioning
Here, I present the method of combining an open source library Optuna (1) based on a Bayesian optimization algorithm, Tree-Structured Parzen Estimator (TPE) with the seismic faulting FEA based on COMSOL Multiphysics and then demonstrate a Baysian optimization for the fault-shape parameters that activates strong slip partitioning.
The parameter sets obtained from the Bayesian optimization algorithm result in a stronger slip partitioning than that obtained from the grid-search. More specifically, the optimized parameter set was found as a dip angle for the reverse-slip fault of 54.5 degree, a dip angle for the strile-slip fault of 86.3 degree, and the principal stress direction of 56.1 degree clockwise from the strike direction.
The Bayesian optimization detected the parameter set after 50 trials, whereas the grid-search was composed of 784 trials. In summary, the use of the Bayesian optimization algorithm is an effective and efficient way of a parameter optimization for a seismic faulting simulation that requires long CPU time.
(1) Preferred Networks, Inc.: https://optuna.org/