Laboratory investigation on salt migration and its effect on the geotechnical strength parameters in quick clay mini-block samples from Dragvoll
Investigations of the effect of salt diffusion as ground improvement of quick clay is important
to provide a clear understanding of the method, to be able validate the potential of commercial
use. Previous extensive investigations by laboratory work has been carried out. Laboratory in-
vestigations of salt migration lead to extended storage time for the clay samples, as diffusion in
clays is considered a slow process.
ing and storage effects. The effect is analyzed in the laboratory with regards to both geotchnical
properties, variations in pH and salinity. A literature study of previous findings related to salt
migration and storage effects on both geotechnical properties and geochemistry, is also consid-
A series of mini block samples are submerged in cells containing deaired, ionized water and
deaired, KCl solution. The samples are stored in the cell in a time period from 42 to 102 days.
The samples are investigated in the laboratory to provide results relating to undisturbed and
remoulded strength parameters, compressibility and general geotechnical properties. pH and
salinity is also recorded. The findings are compared to a detailed depth profile of reference
with regard to the time dependent diffusion and weathering.
in KCl solution, approximately 50% of the observed general increase is also observed in the clay
stored in water. A minor increase of plasticity limit is seen in both the water and salt treated
samples. The comparison between sections for each sample show no clear deviations between
the sections. Further, results from the salt migrated samples confirm the findings from previous
The samples are to some extent effected by weathering, in particular the peak undrained shear
strength resulting from triaxial tests. However, the geotechnical properties observed after salt
migration are changed to such an extent that the clay show a completely different behavior. The
same distinct change is not observed in the clays only exposed to potential weathering.
The comparability between the samples are however, considered to be relatively low due to in-
homogeneity in the soil profile and varying storage time prior to testing and cell installation.
Loss of samples during sampling also lead to occasional large distance in depth, between the
Place, publisher, year, edition, pages
Institutt for geologi og bergteknikk , 2014. , 208 p.
IdentifiersURN: urn:nbn:no:ntnu:diva-27130Local ID: ntnudaim:11359OAI: oai:DiVA.org:ntnu-27130DiVA: diva2:758249
Brattli, Bjørge, ProfessorEmdal, ArnfinnHelle, Tonje Eide