Lookup NU author(s): Professor Stefano Utili
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Purpose – Retained excavation is important for future lunar exploratory missions and potentialhuman colonization that requires the construction of permanent outposts. Knowledge in excavationobtained on the earth is not directly applicable to lunar excavation because of the low lunar gravity andthe non-negligible adhesive van der Waals interactions between lunar regolith grains. The purpose ofthis paper is to reveal how the gravity level and lunar environment conditions should be considered toextend the knowledge in earth excavation response to lunar excavation.Design/methodology/approach – Two-dimensional discrete element method simulations werecarried out to investigate the respective effect of gravity level and lunar environment conditions (highvacuumand extreme temperature) on retained excavation response. A novel contact model wasemployed with a moment – relative rotation law to account for the angularity of lunar soil particles,and a normal attractive force to account for the van der Waals interactions.Findings – The simulation results showed that the excavation response is non-linearly related to thegravity level. Van der Waals interactions can increase the dilatancy of lunar regolith and, surprisinglyas a consequence, significantly increase the bending moment and deflection of the retaining wall, andthe ground displacements. Based on the simulation results, a parabola model was proposed to predictthe excavation-induced lateral ground movements on the moon.Originality/value – This study indicates that an unsafe estimate of the wall response to anexcavation on the moon would be obtained if only the effect of gravity is considered while the effect ofvan der Waals interactions is neglected.
Author(s): Jiang MJ, Shen Z, Utili S
Publication type: Article
Publication status: Published
Journal: Engineering Computations
Print publication date: 01/02/2016
Acceptance date: 24/06/2015
ISSN (print): 0264-4401
ISSN (electronic): 1758-7077
Publisher: Emerald Publishing Limited
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