Caracterisation des proprietes mecaniques du remblai minier rocheux cimente par des methodes non-destructives

his project will focus on analyzing three different cemented rock fill compositions using nondestructive testing techniques over a curing period of 90 days. The main goals are to determine a relationship (or formula) between the physical properties and the mechanical resistance by uniaxial compressive strength (UCS) of the specimens. In parallel, the study can analyze the evolution of the physical properties during the curing period, and suggest an approach for monitoring in-situ backfill remotely. And lastly, the project can help us to interpret when the setting of the cemented rock fill has taken place and when the optimal compressive strength has been achieved. To achieve these objectives, two geophysical techniques (electric resistivity and ultrasonic) are used to monitor the physical properties (resistance and wave velocity), UCS tests are done during and at the end of the monitoring period, and finally, the application of mixture laws to estimate the properties of the rock fill material by its constituents (waste rock and paste). The last approach is in hope to determine a solution to estimate the in-situ mine fill by the results of its constituents found in laboratory.;It is observed that the resistance measured and the calculated resistivity increase with time. The inversion models, mapping the resistivity distribution in volume, allow us to interpret the area of anomaly or area more sensitive to change. The anomalies develop close or on the location where an electrode is badly install. The lose contact between the electrode and the rock fill material explains the ambiguous response. The central zone of the specimens appears to be more sensitive, and the evolution of the electrical resistance can be seen. For the velocity, the measured signals of the P wave and the estimated average velocity by the stretching technic have given satisfying results. The shear S wave is unsuccessfully measured due to noise and low frequency signals; hence the mechanical properties cannot be calculated. However, with only the P wave velocity, it can be observed that the velocity increases with time. The layers that are much denser in the heterogeneous material can also be analyzed. GeoTom software maps the tomography of P wave velocity and it is also observed that the central zone of the specimens is more sensitive to change. This is because the central zone cells (or mesh) have more data than the cells in the other layers. The UCS of the paste cylinders suggests that the strength increases with time (and hardness) as expected. The stability of the strength is reached at about 28 days. The behaviours of the physical properties results also suggest that the hardness has taken place at approximately 28 days. The specimens are broken into two sectional pieces after the UCS testing to do visual observations in the interior of the specimens. These observations also help to confirm the interpretations based on the measured results.;The results of the specimens suggest that, at the end of the monitoring period, the specimen S...