Study on low gravity effect on bearing capacity and slope stability of a new lunar highland soil simulant (LSS-ISAC-1) for futuristic moon habitation

Abstract

The future lunar missions of the space research organizations (SRO) such as the (US) National Aeronautics and Space Administration (NASA), the China National Space Administration (CNSA), the European Space Agency (ESA), the Indian Space Research Organisation (ISRO), the Japan Aerospace Exploration Agency (JAXA), and the Russian Federal Space Agency (RFSA or Roscosmos), etc., comprise extended stay on Moon, making the lunar surface a launchpad for the interplanetary missions and Moon habitation. These are the most challenging task for the space research organizations (SRO) and the researchers, which needs all engineering disciplines. Also, the distinct difference in the environment between the lunar surface (lunar gravity, moonquakes, high temperature, etc.) and the Earth forced the SROs and the researchers to study the geotechnical properties such as specific gravity, particle size distribution, density, shear strength, and bearing capacity of the lunar soils. In this, the lunar gravity (1/6g) significantly influences the bearing capacity of the lunar soil, which is the predominant property for the design and analysis of foundation systems of the lunar structures. Assessing the bearing capacity under the reduced lunar gravity will enhance the evaluation of design criteria for the lunar structures and their foundation systems. In this respect, this paper explains the low gravity effect on the bearing capacity of the new lunar highland soil simulant LSS-ISAC-1 developed to represent the geotechnical properties of the highland soils of the lunar surface. The bearing capacity of the simulant for both the lunar and Earth gravity was evaluated and compared with the lunar soils and lunar simulants. The plate load test and single wheel load tests were performed to determine the sinkage property (compression/settlement) of the LSS-ISAC-1. The slope stability and self-standing height of the LSS-ISAC-1 were also determined for a better understanding of stability. Overall, the comparison results state that the new simulant LSS-ISAC-1 is more than sufficient to support virtually any conceivable structures based on the results.