Pressure condition around the underground opening substructured by anchors in multilayered deposits investigated by the method of final elements

Computer program ADINA is used for pressure analysis on a model of underground opening, semi-circular in shape, where there are the layers of lignite, and conducted pressure analysis, before, during and after the setting of three and five anchors. Theory on pressure distribution for secondary and tertiary pressure condition in the roof and board sides of the opening by setting anchors has been proven. In order to check the result, test of removing anchors from the roof and board sides of the opening was done. Testing and research, conducted at the level of obtained results, show the efficiency of setting underground opening using the anchors where there are multilayered deposits of lignite. The research results, provided in this paper, can be also used for other underground openings containing multilayered deposits.