Characterisation of a Norwegian Quick Clay using a Piezoball Penetrometer

The piezoball, or ball penetrometer with pore pressure measurement, was developed for assessing the geotechnical properties of soft soils, particularly soft seabed sediments where the traditional cone penetrometer can have limitations. The measurement of pore pressure during this test can be beneficial for understanding the soil drainage conditions during penetration and thus assist the interpretation of the soil type and in-situ state. In addition, dissipation tests, where the pore pressure decay with time is monitored during a pause in penetration, can be used to assess the consolidation properties of the soil. In order to add to the experience base of piezoball testing in different soil types, testing was conducted at the Tiller quick clay site near Trondheim, mid-Norway. This paper presented the results of this testing with particular focus on the pore pressure response during penetration and the interpretation of consolidation properties from dissipation tests. © 2016 Australian Geomechanics Society.