The deep oceanic sediments were collected from the Challenger Deep in the southwestern part of the Mariana Trench. Considering the salt in the pore water, a modified method for determining the physical and mechanical properties of the deep-sea sediments was proposed, by which the geological engineering indices were measured and corrected. Through the scanning electronic microscope (SEM), the microstructures of the sediments were found to be composed of flocculation, with a large number of diatom debris and empty shells of organism around it. As a consequence, the porosity and compressibility are high; internal friction angle and cohesion are low. Besides high water content, high porosity, high liquid limit, high plasticity, high consolidation coefficient, low compressive modulus, low shear strength, low density, and low specific gravity, the deep-sea mining machine may slip and subside. This research can improve the understanding of the deep-sea sedimentary environment of the Challenger Deep in the southwestern part of the Mariana Trench and provide an essential reference for the parameter calibration as well as the basis for walking-characteristic study and optimization design of the deep-sea mining vehicle.

中文翻译：

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马里亚纳海沟 Challenger Deep 底部取芯的深海沉积物的物理和机械特性

深海沉积物是从马里亚纳海沟西南部的挑战者深处收集的。针对孔隙水中的盐分，提出了一种改进的深海沉积物物理力学性质测定方法，通过该方法对地质工程指标进行了测量和修正。通过扫描电子显微镜（SEM），发现沉积物的微观结构由絮凝体组成，周围有大量的硅藻碎片和空壳。因此，孔隙率和可压缩性都很高；内摩擦角和内聚力低。除了高含水量、高孔隙率、高液限、高塑性、高固结系数、低压缩模量、低剪切强度、低密度和低比重外，深海采矿机可能会打滑和下沉。该研究可增进对马里亚纳海沟西南部挑战者深部深海沉积环境的认识，为参数标定提供重要参考，为深部行走特征研究和优化设计提供依据。 - 海上采矿车。