A Generalized Formulation for Accurate and Robust Determination of Soil Shear Strength from Triaxial Tests

TL;DR

This paper extends the LSVD method for estimating soil shear strength from triaxial tests, introducing generalized variants that adapt to diverse failure shapes and benchmarking their robustness against noise.

Contribution

It introduces generalized LSVD variants for better modeling of soil failure envelopes and compares their performance with existing methods under measurement uncertainties.

Findings

LSVD variants effectively model complex soil behavior.

Generalized LSVD shows robustness to measurement noise.

Benchmarking demonstrates LSVD's reliability and flexibility.

Abstract

This work presents an extended formulation of the Least Squares with Virtual Displacements (LSVD) method for estimating shear strength parameters from multiple soil samples under varying resistance conditions including cohesionless, frictional, and mixed types. LSVD is designed to identify a common tangent across n Mohr circles, even in the presence of measurement errors that render an exact solution infeasible. Beyond its original linear formulation, we introduce generalized LSVD variants like logarithmic, parabolic, polynomial, power law and generalized forms allowing the method to adapt to diverse failure envelope shapes observed in geotechnical materials. We benchmark these variants against established approaches such as the p-q method and CTPAC, analyzing performance under synthetic noise to simulate measurement uncertainty. This provides a comparative framework to assess each method's robustness, especially considering their differing selections of representative points on the Mohr circles. The results highlight LSVD's flexibility and reliability in modeling complex soil behavior and suggest its potential as a versatile tool for geomechanical analysis.