Numerical Modelling of an Underground Cavern in jointed rock mass

In this dissertation the study of the behavior of an underground cavern in jointed rock granite has been carried out. For this purpose, different analyses were developed, using Finite Element Method software for the modelling in two and three dimensions of the cavern. The main purpose of this master thesis was to create different continuum numerical models which could represent the weathered rock mass using different approaches. One possible approach followed in this project as means to incorporate the influence of joints on rock mass strength in numerical analysis was by modelling rock masses as equivalent continuum with reduced deformation and strength properties. This model was considered as reference in the present dissertation. Another way to model jointed rock masses was through the introduction of special elements such as joint elements, also known as interface elements. In this way, it was possible to implement different continuum models with joints following the joint systems formulated by Dershowitz in 1985. All these models were compared, the continuum model with joints “Cross jointed” was indicated as the one that better represents the weathered rock mass. It was found that this model was the one exhibiting the more similar behaviour and results compared to the equivalent continuum model.