During the excavation of a tunnel in unforeseen abrasive rock, a hydraulic tunnel boring machine (TBM) suffered a cutterhead jam following the massive breakage of its disc cutters. The failure, attributed to thermal fatigue, halted the work for weeks. A 3D pipeline using Artec Studio for damage scanning and FLAC3D to simulate residual stresses in the ground was employed for the incident analysis.
3D Pipeline: Scanning with Artec Studio and Simulation in FLAC3D 🛠️
The team documented the geometry of the fractured cutters using Artec Studio, generating high-precision point clouds. This data was imported into FLAC3D to model rock-disc interaction under extreme thermal conditions. The simulations revealed that the abrasiveness of the rock mass, undetected in previous surveys, generated localized temperature peaks that exceeded the steel's dissipation capacity, causing cracks due to differential expansion. The model allowed for adjusting advance and cooling parameters.
The cutter that took an unscheduled thermal break 🔥
The cutters, which should have lasted at least a couple of kilometers, decided to retire early at meter two hundred. It turns out the rock, instead of being the docile slate the geological report promised, turned out to be a granite splinter with a fighting spirit. Now the engineers debate whether to blame the summer heat or the fact that the discs didn't wear sunscreen. Meanwhile, the TBM patiently waits for its wheels to be changed, like a race car in the pits but with less glamour.