Numerical modelling of laboratory tests for TBM cutter indentation process analysis

Considering that TBMs are nowadays used for long Trans-Alpine tunnels, the<br/>understanding of rock breaking and chipping due to TBM cutter disks mechanism, for deep tunnelling operations, becomes very interesting. In this paper, the results from carried out laboratory tests that simulate the disk cutter action at the rock tunnel face by means of an indentation tool, acting on a rock<br/>specimen with proper size, and the related three-dimensional and two-dimensional numerical modelling are proposed. The developed numerical models simulate the different test conditions (applied load, boundary conditions) allowing the analysis of the stresses distributions along possible breaking planes.<br/>The influence of a confinement-free area on one side of the specimen, simulating the formation of a groove near the tool, is pointed out.<br/>The obtained results from numerical modelling put in evidence a satisfactory agreement with the experimental observations.