Mechanical Analysis of Removable Blocks During TBM Tunnelling in Blocky Rock Masses in View of TBM-Block Interaction

Interaction between TBM and the surrounding rock masses is consist of the cutterhead-block interaction and shield-block interaction, leading to the stability consideration of TBM tunnels. The equilibrium equation of removable blocks is derived by taking into consideration of the interaction forces and the net sliding forces of moving modes is also deduced. For different types of blocks in terms of the new classification of blocks in TBM tunnels, sliding and falling will happen for rear blocks, while front blocks and corner blocks will only experience sliding motion.