Complex estimation of the underground excavations stability in various mining and geological conditions

The paper demonstrates a methodology of a complex stability estimation for underground mining excavations located in salt rock masses. Various geological structures of the rock mass, as well as the most popular safety measures for underground excavations support such as ankers, expansion gaps and reinforced concrete are considered. The proposed methodology is based on a hybrid numerical-analytical method for the determination of the stress-strain state of geotechnical systems as well as on an original complex limit state criterion for rock masses. As the result of the study the main factors influencing the stability of excavations where highlighted and generalized. These factors are: mining depth, mechanical properties of rock mass, its geological structure and safety measures. The degree of the importance of each mentioned factor is established. A number of model problems are solved to prove the efficiency of the proposed method for complete and reliable estimation of rock mass state in the vicinity of underground excavations, as well as predicting the stability of geotechnical structures under various conditions.