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THE INFLUENCE OF SEGMENTAL LINING IN DEEP TBM TUNNELLING
Session: Rock Mechanics and Engineering Geology II / Mécanique des roches et ingénierie géologique II
Ioannis Vazaios, Queen's University (Canada)
Nicholas Vlachopoulos, Queen's University (Canada)
The shield-driven tunnelling method has been mainly adopted for the construction of urban underground tunnels in soft ground due to its flexibility, cost effectiveness and the minimum impact on the ground surface. However, due to the efficiency of the shield-driven tunnelling techniques, Tunnel Boring Machines (TBMs) have also been employed in deep, weak rock tunnelling. In shield-driven, tunnelling techniques the final support is usually composed by assembling pre-cast concrete segments into a ring, and multiple rings placed side-by-side form the final tunnel lining. Due to the ring geometry and joint distribution, segmental liners do not show a two dimensional (2D) behaviour but rather exhibit a three dimensional one (3D). However, due to the complex geometry 2D numerical analyses are employed because of their flexibility and the reduced computational time and cost. For the purposes of this paper, two different types of concrete liners, (i) monolithic, and (ii) segmental liners, are adopted in order to investigate the influence of the in-situ conditions on the structural forces developing in the liner under different ground-tunnel interface conditions.
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