ABSTRACT
A specially designed drilling campaign was carried out in fresh mudrock. Four different modifications of sampling and storage were considered. Two different drilling fluids (clear water, water based polymer fluid) in four different drill holes were used. After coring every second liner was filled with a solution of low salt concentration to avoid wetdry- cycles and osmotic effects during storage. The remaining cores were handled conventionally without any additional treatment. Subsequently the influence of the four different sampling schemes on the effective strength parameters shall be investigated. The saturation and consolidation as well as the Pore Water Pressure (PWP) are regarded as primary influencing factors.
After evaluation of the first results there are indications that the cohesion reveals higher values for samples stored in a low concentrated salt solution. The friction angle does not show a clear trend.
A very interesting finding is the decrease of Skempton’s B during the saturation stage in triaxial tests and its implications on the triaxial testing procedure for slaking material like mudrocks.
