In ocean engineering, polymer layer is often adopted as waterproof materials, and the mechanical behaviour of marine sand-polymer layer interfaces has significant influence on the engineering safety. In the research, based on the bespoke large temperature-controlled interface shear equipment, direct shear experiments were performed on the interfaces between polymer layer and marine sand with the particle size ranging from 1 mm to 2 mm (S1 marine sand) and from 2 mm to 4 mm (S2 marine sand) in the temperature range of-5 degrees C-80 degrees C. The test outcomes manifest that, both the change rules of interface peak shear strength and its sensitivity to normal stress variation are temperature dependent; The variation rules of the interface peak shear strength in elevated temperature are different in diverse normal stress. By adopting the experimental outcomes, machine learning models were established to predict the interface shear stress under the effects of temperature and soil particle, with higher estimating precision and efficiency. The research findings are beneficial for the correct design of marine engineering facilities related to marine sand-polymer layer interfaces.

The high-temperature climate, dynamic stress loading and soil particle dimension have non-negligible influence on the interface interaction between marine coral sand and polymer layer, which determines the stability of coral sand engineering facilities installed with polymers. However, currently, the relevant research is rare. In this paper, by using the self-developed large temperature-controlled interface dynamic shear apparatus, a series of cyclic shear tests were conducted on the interfaces between polymer layer and coral sand with the particle size range of 1 mm - 2 mm (S1 coral sand) and 2 mm - 4 mm (S2 coral sand) in the temperature ranging from 5 degrees C to 80 degrees C. The experimental results indicate that, from 5 degrees C to 60 degrees C, the peak shear strength, dynamic shear stiffness and damping ratio rise, while from 60 degrees C to 80 degrees C, the decline of the mechanical parameters occurs. Also, temperature has more significant influence on the dynamic mechanical properties of S1 coral sand interfaces than that of S2 coral sand interfaces. Additionally, except for 60 degrees C, the peak shear strength, dynamic shear stiffness and damping ratio of S1 coral sand interfaces is all higher than that of S2 coral sand interfaces in other test temperature.