• Cabrera, Miguel Angel
• Delage, Pierre
• Banerdt, Bruce
• Castillo-Betancourt, Juan Pablo
• Lopez, María Juliana Chaparro
• Caicedo, Bernardo
• Lognonné, Philippe

Abstract

The dynamic properties of loose sands under low stresses are an unexplored topic in soil dynamics because these soil conditions are uncommon in most geotechnical structures on Earth. However, low densities and low-stress conditions prevail on other planets, like, for instance, the surface of Mars, for which particular attention is presently given through the InSight NASA mission. This work presents a new procedure for measuring the dynamic properties of loose sand under low stress by using the dynamical mechanical analysis (DMA) tester, a technique commonly used in asphalt engineering but not in geotechnical engineering. Compared to traditional geotechnical methods (resonant column and cyclic triaxial tests), DMA investigates a broader range of strains using a single apparatus. In this work, we assess the dynamical properties of loose fine sand Dr ∼ 0.2, considered a possible Mars regolith analog, by varying the input strain from γ = 10-6 to γ = 10-2 while applying confining pressures from ρ3 =3 kPa to ρ3 = 30 kPa. The results validate the proposed procedure, showing an increment of the shear modulus as the confining pressure increases. Furthermore, they highlight DMA's advantages for studying the dynamic properties of granular soils under low stress and strain. ; Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. ; Geo-engineering

Topics

• impedance spectroscopy
• surface
• dynamic mechanical analysis