An automated system to determine constitutive model parameters from in situ tests

Abstract

Selecting an appropriate soil
constitutive model and determining the corresponding model parameters for
numerical analysis are considered most challenging in geotechnical engineering.
While many empirical relationships have been proposed to derive soil parameters
from in situ test results, there is no clear procedure on how to derive model
parameters uniquely. In practice, available data during the early stages of
projects is often limited to field test data. Consequently, different engineers
provide different numerical solutions for the same problem. As a solution, the
authors present a proof of concept for an automated parameter determination (APD)
system, using concepts of graph theory to determine constitutive model
parameters from in situ tests while keeping the system transparent (verifiable)
and adaptable (extendable). The study aims to increase the confidence in
parameter determination for numerical analysis by giving the user of the
system, the geotechnical engineer, control over the system. Using a spreadsheet
of parameters and equations as input, the system generates paths between the
parameters and calculates the parameter values for coarsegrained soil, starting
from CPT data. Further validation and tweaking of the system, as well as the
extension to other types of soils, are part of ongoing research.