DEM modeling of cantilever retaining excavations: implications for lunar constructions

Abstract

Users who downloaded this article also downloaded: (2016),"Simulation of one dimension shock initiation of condensed explosive by SPH method", Engineering Computations, Vol. 33 Iss 2 pp. 528-542 http://dx. (2016),"Routing algorithm with QoS constraints for real time multicast communications using particle swarm optimization and genetic meta-optimizer", Engineering Computations, Vol. 33 Iss 2 pp. 344-365 http://dx.(2016),"A new strain-based finite element for plane elasticity problems", Engineering Computations, Vol. 33 Iss 2 pp. 562-579 http://dx.If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -Retained excavation is important for future lunar exploratory missions and potential human colonization that requires the construction of permanent outposts. Knowledge in excavation obtained on the earth is not directly applicable to lunar excavation because of the low lunar gravity and the non-negligible adhesive van der Waals interactions between lunar regolith grains. The purpose of this paper is to reveal how the gravity level and lunar environment conditions should be considered to extend the knowledge in earth excavation response to lunar excavation. Design/methodology/approach -Two-dimensional discrete element method simulations were carried out to investigate the respective effect of gravity level and lunar environment conditions (highvacuum and extreme temperature) on retained excavation response. A novel contact model was employed 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 the gravity level. Van der Waals interactions can increase the dilatancy of lunar regolith and, surprisingly as a consequence, significantly increase the bending moment and deflection of the retaining wall, and the ground displacements. Based on the simulation results, a parabola model was proposed to predict the excavation-induced lateral ground movements on the moon. Originality/value -This study indicates that an unsafe estimate of the wall response to an excavation on the moon would be obtained if only the effect of gravity is...

Calculation of the Influence Zone for Planetary Sampling Based on DEM Simulation

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Multi-objective optimization-based updating of predictions during excavation

“…Some studies (Kung et al, 2007;Kung et al, 2009;Schädlich and Schweiger, 2012), have innovatively considered the small strain stiffness behavior of soils and obtained accurate predictions. In addition, due to its natural deposition, the soil always exhibits naturally inherent cross-anisotropy of elasticity (Jiang et al, 2016a;Jiang et al, 2017), which has a significant effect on lateral wall deflection and ground movement in an excavation (Jiang et al, 2016b;Teng et al, 2014). Due to the integrity that exists between the soil and the structure in an excavation, associating the structures' parameters (e.g., stiffness of the diagram wall, of supporting structures) with the soil parameters in the optimization could give more accurate predictions of the wall and ground responses.…”

Micromechanical Behavior of DNA‐1A Lunar Regolith Simulant in Comparison to Ottawa Sand

“…There is particular interest in the study of the behavior of the lunar regolith at low effective stresses, but such experiments are difficult to be performed in the laboratory due to the effect of terrestrial gravity and the models used should be scaled for Moon's gravitational acceleration (Cafaro et al, 2018;Hasan & Alshibli, 2010;Sture et al, 1998). Hence, cost-effective numerical modeling tools such as the discrete element method (DEM; after Cundall & Strack, 1979) have been implemented for the simulation of the lunar regolith and its interactions with rover vehicles (Knuth et al, 2012;Li et al, 2010;Nakashima et al, 2010Nakashima et al, , 2011Sullivan et al, 2011) and retaining structures (Jiang et al, 2016).…”