EFFECT OF SHAPE OF TUNNEL ON ITS STABILITY

Abstract

Due to rapid urbanization, the role of underground construction is increasing day by day. Underground tunnels are used for several purposes such as storage space, transportation, sewage, water and, oil delivery, and so on. Due to the constant pressure of high-rise residential buildings and, traffic movement, tunnels can be damaged. Hence, the study of stability assessment is very imperative. Many researchers have been proven that the stability of a tunnel depends on various factors like cover depth, type of loading, material properties, etc. This paper investigates the stability appraisal of different shapes of the tunnels in rock mass under static load. Finite element software, ANSYS has been used for numerical modeling and investigation of the static response of different shapes of 3-D shallow tunnels, which are Circular, Horse-shoe, Box Shape, and Semi-ellipse considering the same cross sectional area under static loading conditions. In the paper, a load has been applied as pressure through a steel patch on top of the tunnel. A 3-D finite element model has been taken for the numerical study with a constant C/D ratio. This paper aims to compute longitudinal deformation on the lining and crown of each tunnel. The failure of the tunnel along the tunnel axis has been investigated. The conclusion of the study represents that the most stable shape is circular from a deformation point of view among all the tunnels when subjected to static loading conditions.