Tunnelling in bimunits with different block-matrix characteristics: A preliminary numerical study

e aim of this paper is to investigate the different mechanical responses of a deep circular tunnel excavated (virtually) in different bimunits (block-in-matrix units), which include a wide range of heterogeneous geological deposits. The three main categories identified and analysed are hard-bimrocks, soft-bimrocks and bimsoils, with block contents ranging from 25% to 55%. For this purpose, 2D finite element simulations are carried out. Special attention is paid to the simulation of the block-matrix contacts, which depend on the bimunit category.