An experimental study on the moisture migration characteristics of liquefiable iron ore

Abstract

Cargo liquefaction is still the biggest causes of casualties during its sea transportation. To understand the liquefaction mechanism deeply, research of moisture migration characteristics of liquefiable cargo is the priority. Closer to the actual transportation conditions of iron ore, unsaturated undrained, saturated undrained and saturated drained experiments were all carried out. Effects of ship motion accelerations, frequencies and sample densities were also taken into account. Results indicate that the largest drainage happens in the first ten minutes when drained, and accounts for 75.3% of the total volume. The external loads have a little promotion for the drainage. The pore water pressure dissipates quickly and its value goes below zero. When undrained, the water would migrates upward and the middle part have a relative higher water content. The pore water pressure accumulates and increases quickly in the first 50–100 s, and also the middle part has the largest increase of pore water pressure. A larger motion acceleration could enhance the accumulation of the pore water pressure and the water migration. There are critical motion frequencies, under which the accumulation of the pore water pressure and the water migration become obvious. For the sample with a higher density, the accumulation of the pore water pressure and the ability of water migration are all bounded. This study could be provided as an useful reference to reveal the liquefaction mechanism.