Mechanism of low-disturbance and high-pressure-retaining sampling of seafloor sediments at 10000-meter depth and its laboratory experiment and on-site sea trials

• A novel deep-sea sediment pressure-retaining sampler achieves pressure preservation rates of 94.21% and 92.02% at depths of 9298.4 m and 9142.8 m, significantly exceeding the current 80% technical indicator. • A radial disturbance model based on spherical cavity expansion theory was developed to quantify sediment disturbance, using the plastic deformation radius as an evaluation index. • Indoor experiments with embedded sensors validated the theoretical model, confirming the accuracy of predicted radial stress and pore water pressure distributions. • On-site sea trials in the Kuril-Kamchatka Trench retrieved sediment samples with clear stratification and minimal disturbance, demonstrating the sampler's effectiveness for deep-sea geological research.