Horizontal spatial variability of elastic modulus in sand from the dilatometer

Abstract

Probabilistic modelling of soil profiles requires knowledge of three statistical parameters – the mean, standard deviation (or similar measure of the variance) and the scale of fluctuation, which provides information regarding the continuity or randomness of the soil property under investigation. The first two parameters are relatively simple to quantify, however, the third requires testing that is normally beyond the scope of the vast majority of site investigations. This paper aims to quantify the scale of fluctuation of the Young’s modulus of elasticity of a sand based on flat dilatometer tests (DMTs). Almost 500 DMTs have been performed along a horizontal line, 50 metres in total length. The horizontal interval between tests was 0.5 m, whilst the vertical spacing was 0.2 m. Random field theory and geostatistics are applied to the data in order to evaluate the scale of fluctuation. It is observed that the scale of fluctuation associated with the elastic modulus is of the order of 1.5 metres.