Shear creep parameters of simulative soil for deep-sea sediment

Based on mineral component and in-situ vane shear strength of deep-sea sediment, four kinds of simulative soils were prepared by mixing different bentonites with water in order to find the best simulative soil for the deep-sea sediment collected from the Pacific C-C area. Shear creep characteristics of the simulative soil were studied by shear creep test and shear creep parameters were determined by Burgers creep model. Research results show that the shear creep curves of the simulative soil can be divided into transient creep, unstable creep and stable creep, where the unstable creep stage is very short due to its high water content. The shear creep parameters increase with compressive stress and change slightly or fluctuate to approach a constant value with shear stress, and thus average creep parameters under the same compressive stress are used as the creep parameters of the simulative soil. Traction of the deep-sea mining machine walking at a constant velocity can be calculated by the shear creep constitutive equation of the deep-sea simulative soil, which provides a theoretical basis for safe operation and optimal design of the deep-sea mining machine.

基于深海沉积物的矿物成分和原位十字板剪切强度，通过将不同的膨润土与水混合制备了四种模拟土，以找到适用于太平洋C - C区采集的深海沉积物的最佳模拟土。通过剪切蠕变试验研究了模拟土的剪切蠕变特性，并利用伯格斯蠕变模型确定了剪切蠕变参数。研究结果表明，模拟土的剪切蠕变曲线可分为瞬态蠕变、不稳定蠕变和稳定蠕变，由于其含水量高，不稳定蠕变阶段非常短。剪切蠕变参数随压应力增加而增大，随剪应力变化较小或波动并趋近于一个恒定值，因此将相同压应力下的平均蠕变参数作为模拟土的蠕变参数。通过深海模拟土的剪切蠕变本构方程可以计算出深海采矿机匀速行走时的牵引力，这为深海采矿机的安全运行和优化设计提供了理论依据。