Use of an up-scaled DEM model for analysing the behaviour of a shallow foundation on a model slope

Abstract

This paper presents a methodological approach for the DEM modelling of geotechnical problems. The approach is based on quite general principles, which are illustrated with reference to a specific problem, i.e. the reproduction of a physical model of a foundation on a sandy slope. The approach mainly consists in the reproduction of the involved soil using a small, but statistically representative, assembly of spheres characterized by the same porosity and a slightly simplified grain-size curve. The DEM parameters are calibrated on the base of some standard compression tests on the same material utilised in the physical model. The thus calibrated DEM model is finally utilised to reproduce the tests on the model foundation, but, to limit the computational effort in this latter phase, an up-scaled grain-size curve is adopted and the corresponding DEM parameters are determined using the scaling rules provided with the approach. The performance of the numerical model in predicting the experiments is assessed by comparing both global results (foundation load–settlement curves) and local measurements (strain field). Moreover, the DEM model is finally used to test the foundation behaviour in some different loading conditions that could not be investigated in the laboratory.

Keywords:

• discrete element method
• granular soil
• physical model
• shallow foundation
• model calibration