One-dimensional compression of volcanic ash of Mount Etna

摘要

This paper presents the results of both a physical and mechanical characterization of a volcanicrnash, the Etna Sand, collected during a recent eruptive event of Mount Etna. The interest for this material,rncommonly found in the areas surrounding the volcano, stems from its compressibility and the crushable nature ofrnthe sand grains. For both these aspects, Etna Sand is a problematic material from an engineering and constructionrnviewpoint. The physical and mechanical characterization involved X-ray diffractometry and electron scanningrnmicroscopy (SEM), to analyze mineralogy and microstructure, and one-dimensional compression tests carriedrnout on both wet and dry soil specimens characterized by different initial densities. In order to examine the effectsrnof the loading on the evolution of the micro-structure, the authors analyzed by means of the Qicpic apparatusrnboth the particle size distribution and the particle shape before and after the tests. When the specimen is tested atrnvertical pressures larger than 1MPa the grain crushing becomes evident, whereas for values larger than 10MParnthe grain crushing process seems to be progressively inhibited.