Increasingly used in underground mines in Québec, paste backfill structures are fragile structures, whose mechanical strength is subject to numerous factors that vary with time. Despite all the precautions involved in their construction, dimensioning, installation and subsequent control, they still present safety risks for miners. By considering the mechanical, thermal and hydric aspects of these structures, the researchers will develop various models to produce a box of integrated tools intended for mining engineers who design them. This project will allow even safer mining backfills to be designed as well as a more reliable analysis of their stability, particularly over the long term. This contribution to the reduction of the risks of failure of these underground developments will increase worker safety, while improving the effectiveness of activities in mining operations.