Soil classification of NGTS sand site (Øysand, Norway) based on CPTU, DMT and laboratory results

Abstract

The Norwegian GeoTest Site project (NGTS) established five research sites in Norway in 2016. The sites are referred to as sand, soft clay, quick clay, silt and permafrost. The project is funded by the Research Council of Norway and the aim of the project is to establish, characterize, share digital data and manage the use of the test sites in the coming 20 years. The sites are open to other researches for developing and calibrating new tools and techniques. The focus of this paper is the soil classification of the NGTS sand site at Øysand based on cone penetration tests (CPTUs) and dilatometer tests (DMT). The fluvial and deltaic deposit at Øysand consists of a 20-25 m fine silty sand with occasionally high content of gravel. The deposit is generally normally consolidated in loose to medium dense states. The in situ test data is further supported by laboratory test results from a 20 m long and continuous borehole. This paper presents the results of two CPTUs and one DMT in addition to laboratory test results, all from the same location at the research site. The prediction of soil behavior type and unit weights from CPTU and DMT tests, based on existing correlations, are compared qualitatively to the soil classification from grain size distribution and unit weights from laboratory measurements.

Soil classification of NGTS sand site (Øysand, Norway) based on CPTU, DMT and laboratory results