Influence of time on the small strain shear modulus of an allophanic volcanic ash Mukteshwar Gobin, Noriyuki Yasufuku, Midori Watanabe, Guojun Liu and Ryohei Ishikura E3S Web of Conf., 544 (2024) 01005 Published online: 02 July 2024 DOI: 10.1051/e3sconf/202454401005