Ultrasonics and RACOS®

Evaluating the propagation properties of seismic waves in rocks is a powerful tool for the determination of rock deformation characteristics. If suitable frequencies are used, the sound waves react in a very sensitive manner to loosening, hollow spaces and cracks in the tested material and are thus used for crack detection or for the depiction of the development of micro-cracks under changing stress conditions. At Gesteinslabor Dr. Eberhard Jahns, the velocities of both compression and shear waves (transversal waves) can be determined in a laboratory experiment. Based on these experiments, moduli such as the dynamic Young’s modulus or dynamic bulk modulus can be calculated – a useful measure to calibrate static vs. dynamic moduli.

RACOS® (Rock Anisotropy Characterization On Samples) is a set of procedures for determining the 3D in situ stress on core samples (Braun 2006, Braun 2008; for further information please visit the homepage of Dr. Roland Braun Consultancy in Rock Mechanics). Measurements of the directional propagation velocities of P- and S-waves under hydrostatic loading allow for the determination of the strain elasticity and seismic anisotropy ellipsoids. These data enable some conclusions to be drawn about the fabric and the structural inventory of the rock body. In this respect most important is the determination of the recent 3D in situ stress field from which the drill core was taken at depth.

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News

05.05.2025 · DGMK Spring conference 2025

DGMK/ÖGEW spring conference 2025 goes on tour and we are part of it!

Meet us on booth 2, we look forward to a lively exchange in Papenburg.

 

03.10.2024 · Project HENRI

Gesteinslabor Dr. Eberhard Jahns is project and research partner within the HENRI (Hydrogen Energy Reservoir) project.

Main focus of us is the impact of H2 on the cap rock. Besides other parameters, we determine the capillary threshold pressure with different gases and gas mixtures.

First preliminary results could be presented at the 2nd HENRI conference.

 

28.07.2023 · Find us in EEK

Recently, the article "Determination of capillary threshold pressure with hydrogen gas" was published in the journal EEK.
Article from the journal EEK 01/2023

01.12.2022 · 

Gesteinslabor has successfully completed the development of a new test rig to determine the capillary threshold pressure with hydrogen.