Evaluation of spatial soil variability in the Pearl River Estuary using CPTU data

Abstract

For a project in the Pearl River Estuary a very extensive site characterisation was carried out. The aim of this paper is to use this extensive investigation campaign to understand the spatial variability of the soil in both horizontal and vertical directions based on cone penetration tests with pore pressure measurement (CPTU). The investigated area stretches over 6762m length and 50m width covering an area of 338100m2 with CPTU soundings every 25m. Based on boreholes and CPTU soundings the stratigraphy is known and thus the correlation characteristics can be estimated specifically for the individual soil types. Soil types found in the Pearl River Estuary are: marine clay and sand, continental clay, marine alluvial clay and sand, fluvial alluvial clay and sand. For all these soil types the vertical and horizontal scales of fluctuation are assessed. This is an important parameter for probabilistic analysis of geotechnical problems such as settlements, differential settlements, bearing capacity and slope stability.