JOURNAL OF ROCK MECHANICS

JOURNAL OF ROCK MECHANICS

Numerical Modeling of the Stability of Intersection Resulted from Slope Tunnel and Access Tunnel in Tabas Coal Mine

Document Type : Original Article

Authors
Department of Mining Engineering, Amirkabir University of Technology, Tehran, Iran.
Abstract
Due to the complexity of the tunnel network design in underground mines, these mines usually have multiple intersections, the stability of which is of great importance. In this study, the stability of one of the junctions of the Tabas coal mine has been investigated. In this regard, the displacements at the junction of the junction have been investigated using the finite difference numerical method in the FLAC3D software environment. The inclined tunnel support system has been defined as fully injected abutments with a radial arrangement of 2.4 m in length and sliding steel frames with a spacing of 600 mm. The access tunnel support system and the trapezoidal-shaped section of the intersection have also been used with 3 and 2.7 m abutments in the roof and wall, respectively, as well as steel frames consisting of IPB260 and IPB320 beams. The results show that the maximum vertical displacement of the inclined tunnel roof before the access tunnel excavation is 29.3 cm, but after the access tunnel excavation it increases to 35.4 cm. The vertical displacement resulting from the intersection excavation in the inclined tunnel occurs mainly on the rock base side of the closed angle side. Also, with increasing distance from the intersection, the displacements decrease; so that the rate of decrease in displacement in the inclined tunnel on the open angle side is greater than that on the closed angle side.
Keywords

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