IDENTIFICATION OF BONDED CLAY PARAMETERS IN SBPM TESTS: A NUMERICAL STUDY

Nubia Aurora Gonzalez, Marcos Arroyo and Antonio Gens

ABSTRACT: A bonded elasto-plastic soil model is adopted to simulate self-boring pressuremeter tests. Calibration of the model with results from several natural clays identifies a meaningful parameter range for the simulations. Then a systematic sensitivity analysis of the loading SBPM test curve is carried out with an infinite cylindrical cavity analogue, focusing on the variables and parameters that are specific to the bonded material. This analysis reveals that the effects of mechanical overconsolidation and bonding on the pressuremeter loading curves are very similar. Unloading and strain-holding phases of the test show a greater capability to separate mechanical overconsolidation from bonding. The limited effects of finite pressuremeter length and partial drainage on the simulated curves do not change those conclusions.

Key words : bonded soils, elasto-plasticity, numerical modelling, pressuremeter  (IGC: C3/E13)