Characterisation of the human influence of near-shore soft clay layers in site investigations

¹ ELU Konsult AB, Sweden
² KTH Royal Insitute of Technology, Sweden

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Soft marine clay layers have been confined beneath thick gravel and rock fills as a result of extensive landfilling along the Stockholm coastline. These clays have been subjected to remoulding and subsequent reconsolidation under complex stress states involving both vertical loading and shear stresses induced by slope geometry. This paper presents a case study of such encapsulated near-shore clays based on CPT, CRS oedometer and CAU triaxial testing. The results show that interpreted overconsolidation ratios are frequently close to unity, while CPT- and fall cone-derived undrained shear strengths are lower than values obtained from consolidated triaxial testing. The findings indicate that standard empirical correlations developed for naturally deposited marine clays are not directly applicable to anthropogenically modified deposits, highlighting the need for adapted interpretation strategies in slope stability assessments.