Abstract

The paper describes in situ testing recently carried out in Keuper Marl using the Hughes high-pressure dilatometer for which an extensive study into calibration and its effects on results was made. The various calibrations performed are described followed by discussion of the effects of calibration corrections on the results obtained. The findings illustrate the importance of proper calibrations before and during a pressuremeter testing programme. In particular, the significance of membrane compression calibrations when testing mudstones classified as weak to moderately weak or stronger is highlighted.