Interface Shear Response of JSC-1A, GRC-3, and JSC-Mars1 Regolith Simulants

Abstract

The response of soil–structure interfaces is of primary importance for the construction and design of infrastructure because all loads, whether static or dynamic, are transferred to the ground through these interfaces. This paper presents a laboratory investigation that characterizes the interface shear response of two lunar simulants, JSC-1A and GRC-3, and one Martian simulant, JSC-Mars1. Through a series of axial and torsional interface shear tests, this investigation thoroughly studies the effect of continuum surface roughness magnitude on the interface response and demonstrates that the JSC-1A simulant mobilizes the largest interface strength, followed by JSC-Mars1 and then GRC-3. Furthermore, the results indicate that torsional shearing against regolith mobilizes larger peak interface friction angles than those mobilized during axial shearing. A methodology for isolating the interface friction response from the passive resistance components is presented, and it is shown that the passive resistances are responsible for the difference in mobilized axial and torsional interface strength. A discussion of the implications of interface response on space exploration, as well as extraterrestrial immobility and infrastructure development, is included.