NUMERICAL EVALUATION OF THE DILATOMETER TEST – AN IMPROVEMENT ON CORRELATIONS

January 7, 2026

A numerical approach is used to characterize the relationship between sand state and the normalized horizontal stress index KD⁄K0 from the Marchetti dilatometer test (DMT) to gain insight on extraction of geostatic stress conditions and soil stiffness from DMT data in sands. A 3D model of the DMT was implemented in Plaxis3D using the inbuilt NorSand model to simulate the DMT test, including both the insertion and subsequent expansion. The model was validated using DMT tests in Busan Sand, conducted using a calibration chamber, which were supported by extensive triaxial testing providing the soil properties. Provided that elastic shear rigidity Ir can be determined by means of geophysical method (readily done), the present investigation suggests numerical modelling of the DMT will be useful for characterizing in situ plastic modulus (which depends on soil fabric) as well as improving the understanding of geostatic stress by avoiding empirical correlations that neglect soil properties. The methodology developed is easily applied in engineering practice.

Shen, H. 2025 " Numerical Evaluation of The Dilatometer Test – an Improvement on Correlations,” Australian Geomechanics Journal Vol. 60, No. 4, pp 67-80, Pub December 2025, Australian Geomechanics Society