TC4 was originally designed and implemented as a potential Test Case of the DECOVALEX I project concerning the coupled hydro-mechanical processes of single rock fractures under controlled laboratory test conditions, carried out at Helsinki University of Technology and supported by VTT. The test was conducted using a MIT 815 Rock Mechanics Test System with servo-controlled mechanical loading and temperature controlled chamber with a rock sample of 102 mm in diameter and 100 mm in height, containing one single fracture for fluid flow, under an axial load of 80 MPa, a confining pressure of 10–16 MPa with loading rate varying from 0.1 to 08 MPa/sec and a flow rate of 0.05 cm3/sec for 600 seconds. Heating was not included in the test. Figure 8a shows an illustration of the tested sample chamber and the rock fracture sample, and Figs. 8b and 8c show results of fracture conductivity vs. effective stress for sample number 2111A and 2411B, respectively.
Unfortunately, no numerical simulations were conducted due to the fact that delays in the final test schedule and resulting assessments meant that the test could not be simulated by the research teams within the project’s schedule.