Development of methods

One group of experiments comprises the development of new research and measurement methods, particularly adapted to the Opalinus Clay, such as, new excavation and drilling methods, extraction of valuable drillcores, and measurement and monitoring of pore-water pressure and rock stress.

In a gallery of the Mont Terri rock laboratory a researcher inserts a packer system into a horizontal borehole.
Installation of measuring instruments in a borehole

Because virtually no water can pass through Opalinus Clay, special hydrogeological test methods and programmes have to be developed for the evaluation of the acquired data. This pertains, for example, to measurement of pore-water pressures, determination of permeability, and extraction of water samples. To drill stably in argillaceous rock and extract undisturbed core samples, we must continually adapt and improve drilling and core extraction techniques. Today’s methods for investigating stress fields in the rock and around the tunnels, which are commonly used for crystalline rock, are only partially successful for argillaceous rock and must therefore also be further developed.

Moreover, coupled processes (such as reciprocal effects of change in temperature, water content, and/or pressure conditions) impose new types of requirements on the methods for investigating the processes that we study in the Mont Terri rock laboratory.