中文摘要：

针对取样于太平洋C-C矿区的深海稀软底质土，采用激光粒度分析、液塑限联合测定、氮吸附、固结和直剪等方法对其开展物理和力学性能研究，并通过X射线衍射法和电镜法分析其矿物组成成分和微观结构。研究结果表明深海稀软底质土为以粉粒为主的黏质土，具有高液限、高塑性，高比表面积、高固结系数、低压缩模量、低抗剪强度等特性，极易造成集矿机的沉陷和打滑。该土样的矿物成分主要由蒙脱石、石英、长石、云母、绿泥石和蛇纹石组成，显微结构为以粉粒和微生物碎片为主的片状链接结构和以黏土矿物为主的蜂窝状絮凝结构相互填充而成。深海稀软底质模拟土的配置原则应以矿物成分、粒径、含水率、比表面积和剪切强度为主，且综合考虑液限、塑限和显微结构。研究结果将为深海集矿机行走特性研究及其优化设计提供重要依据。

英文摘要：

The deep-sea sediment is exploited in the Pacific C-C district by our research group. Its physico-mechanical properties arestudied by analysis of laser particle size, test of liquid and plastic limit, tests of nitrogen adsorption, consolidation and direct shear,and its mineral compositions and microstructures are analyzed by X-ray diffraction（XRD） and scanning electronic microscope（SEM）methods, respectively. Test results show that the deep-sea sediment is clay soil with predominant silt. It has properties of high liquidlimit, high plasticity, high specific surface area, high consolidation coefficient, low compressive modulus and low shear strength,which easily results in slip and subsidence of the deep-sea mining machine. It is mainly composed of montmorillonite, quartz,feldspar, mica, chlorite and serpentine, with sheet-linked microstructure of silt and microbial debris filling with honeycombflocculation microstructure of clay mineral together. The simulative soil substituting for the deep-sea sediment should be preparedbased on the mineral composition, particle size, water content, specific surface area and shear strength as well as liquid limit, plasticlimit and microstructure of the deep-sea sediment. The research results can provide an important basis for walking-characteristicstudy and optimization design of the deep-sea mining machine.