Determination of stiffness and strength parameters for the hardening soil model based on the simplicial homology global optimization and triaxial compressive test.

Constitute model calibration and their parameter determination are essential to scientifically and accurately characterize soil mechanical behavior. However, this is a challenging task due to the complexity of the geomaterials in geotechnical engineering. This study developed a novel model parameters determination framework combining simplicial homology global optimization (SHGO) and triaxial compressive test. The triaxial compressive test was utilized to generate and record test data, which characterize the constitutive law and cover the mechanical behavior. SHGO was employed to capture the mechanical and failure mechanism by minimizing the discrepancy between the test strain-deviatoric stress curve and that predicted by the hardening soil (HS) model using the unknown model parameters. The developed framework was verified and illustrated by a synthetic example based on the HS model. The results show that the determined strain-deviatoric stress curve is in excellent agreement with the test curve. SHGO performed excellently during the determination of model parameters. Then, the developed framework was applied to an actual triaxial compressive test. The results conclude that the developed framework provides an excellent way to calibrate the model and determine its parameters using optimal technology based on test data. The developed framework provides a scientific, reliable, and promising framework for geomaterials' parameter determination and model calibration.