Impact of specimen height on bender element testing of dense sand

A reliable determination of the small strain shear modulus (Gmax ) becomes increasingly critical for novel designs of offshore wind foundations for many limit states. Bender elements (BE) mounted in triaxial or direct simple shear test setups are widely used to measure Gmax . A recent study shows that Gmax can be reliably and repeatably determined with BEs installed in a triaxial test setup for a clean sand (Carotenuto et al. 2020). However, the consistency of BE results when testing sands in test setups with smaller specimen heights have not been investigated to the same extent. Therefore, a rigorous laboratory programme was performed to consistently investigate the impact of specimen height on BE Gmax measurements of a clean dense sand. The results were compared with BE Gmax values from triaxial and resonant column test setups. The interpretation of BE measurements appears to be complicated by travel length and hence specimen height.