3 Dimensional Structural Modelling of Segmental Tunnel Lining Using Finite Element Software

Closed-face shielded TBM driven tunnels are supported using precast concrete segmental linings. In the past these types of lining have been assessed without consideration being given to the coupling action along circumferential joints of adjacent rings or the true behaviour of joints along longitudinal joints, especially where these have a taper. The mechanical and geometrical characteristics of these joints strongly affect the structural behaviour of tunnel lining. The current practice is to use closed form solutions or adopt two-dimensional ‘beam-spring’ modelling techniques to assess the structural behaviour of segmental linings when loaded. However, it can be argued that this simple two-dimensional approach do not fully take account of the coupling action or joint behaviour and so will not provide accurate results. Particularly with respect to: the structural behaviour of the tunnel lining in longitudinal direction; the deformation of the lining due to the rotation along longitudinal joints; and the relative displacement in the circumferential joints.