Large-scale true-triaxial rock testing apparatus

EPJ Web of Conferences, vol. 385, pp. 04002

Abstract

The True-Triaxial Apparatus is designed to accommodate 30 x 30 x 45 cm rock specimens at the Institute of Geomechanics and Underground Technology (GUT), RWTH Aachen. Initial experiments were designed to observe fracture propagation and rock behavior of dry igneous rocks undergoing hydraulic fracturing, with the aim to improve understanding of enhanced geothermal systems at target depths of 3-5 km. A suite of monitoring sensors, including embedded seismic sensors, for AE fracture detection and location, provide a live data feed during experiments in which three sets of flat-jacks induce independent axial stresses on the specimen of up to 35 MPa. Since the initial experimental campaign, the setup has been extended to include conventional cylindrical specimens (diameter = 25 cm; height = 45 cm) to determine the effect of stress on permeability of reservoir rocks; split specimens for shear testing and stress monitoring in fractures, exploring the relationship between fracture roughness on shear strength; and embedded sensor testing in concrete blocks for radioactive deep geological repositories. This contribution focuses on the description of the equipment, initial use cases and future extensions.

Authors 2

1. Alexander Cadmus corresponding Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH, GUT

2. Raul Fuentes Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH, GUT