STRESS AND STRAIN ANALYSIS AROUND UNDERGROUND ROOM

• Published in: Rudarsko-geološko-naftni zbornik 2000-12, Vol.12 (1), p.59-66
• Main Authors: Krešimir Tor, Lidija Frgić, Antonia Jaguljnak Lazarević
• Format: Article
• Language: English
• Subjects: failure criterion; Finite Element Method; underground room
• ISSN: 0353-4529; 1849-0409

By excavation of opening in the rock, a stress concentration around the opening occurs. The state of stresses and strains around an opening is analysed by theory of elasticity and by Finite Element Method (FEM).The aim of the paper is to determine the dimension of the FEM model for the stress and strain analysis around an elliptical opening in rock massif. The numerical calculation have been performed for two different boundary conditions: with forces or with displacements. Boundary conditions given by displacements give better approximation in the state of stress and strains. An example of the excavation of a road tunnel is used to represent stress concentration at the opening and the places where the plastic zones occur. The computation has been done after FEM comprising the Hock-Brown criterion of failure. The results of stability analysis point to the zones where failure of the rock material may be anticipa¬ted. This is important when planning and designing the primary supp¬orts. The comparison of the results of numerical modelling and field recording during excavation is of particular significance (the paper is published in Croatian).