Strength and dilatancy for interface between sand-diatomite mixtures and biomimetic plates

Abstract

The symbiotic relationship between coral and diatoms leads to the calcareous sand-diatomite mixtures (CSDMs) is prevalent in the marine sediments. The interaction between CSDM and structures, such as piles and suction caissons, is crucial for the safe operation of offshore engineering. In the current investigation, we performed a sequence of interface shear tests between CSDM with different diatomite contents (DCs) and biomimetic plates with unsymmetrical morphological shapes inspired by the abdominal scales of snakes. From the test results, we find that the DC has different effects on the interface shear strength of the caudal and cranial shear directions, which shows that the interface peak shear strength (IPSS) of caudal shear direction initially hoists and then declines with enhancing DC, and there exists a critical DC that is essentially consistent with the threshold value of the DC in the mixtures, whereas the IPSS declines with increasing DC for cranial shear direction. In addition, the increase in DC results in higher initial contraction, lower dilatation, and less softening behavior. DC has the same effect on the particle breakage for both caudal and cranial shear directions, i.e., the relative particle breakage index declines with increasing DC for both shear directions. It is anticipated that the current study will provide an insight into the using of the new bioinspired structure in the offshore engineering field.