Analysis of the stability of micro-tunnels in lunar regolith with the Discrete Element Method. (July 2022) - Pelech, T.
Abstract: Applications of tunnels on Earth range from exploration, exploitation, transportation, infrastructure to human habitation. Similarly with the increased focus on habitation on the Moon, tunnels will be required to support these operations. Geomechanical properties are key factors to successfully drill a tunnel. These properties along with excavation dimensions must be appropriate for the tunnel's stability. The research outlined in this paper aims to determine the stability of small diameter horizontal tunnels in lunar regolith and conditions using the capability of the Discrete Element Method (DEM). The YADE DEM program was used for the numerical analysis in this paper. Lunar regolith data from various published papers and simulated triaxial testing has been used for model calibration. Results yield a tunnel stability chart showing size and stability increases with sample compaction and decreases with an increase in tunnel diameter. Seismicity tests also show that low level vibrations destabilise the tunnel with ease. Highlights: Application of the Discrete Element Method including calibration to lunar geomechanics. A tunnel stability chart showing the maximum expected diameters of stable horizontal tunnels in lunar regolith. Modelling of tunnel stability under seismic conditions using lunar data.