Liquefaction potential evaluation for iron ore fines based on a correlation between moisture content and cyclic strength

Abstract

Iron ore fines (IOFs) are indispensable material for industries with over million tons transported annually by sea. The transportation involves serious risk of marine accidents due to cargo liquefaction caused by the loss of shear strength under cyclic loads. In this work, the effect of moisture content on the unsaturated shear strength of the IOFs was analyzed, including the matric suction and the effective normal stress. The cyclic strength of the IOFs as a function of moisture content and number of cycles was presented, as well as a correlation between the cyclic strength ratios in the field and laboratory tests. Moreover, dynamic geotechnical centrifuge model tests were conducted to mimic the field condition and verify the method for liquefaction potential evaluation of the IOFs. The results showed that moisture content was the critical factor affecting the shear strength of the IOFs. The zones with high liquefaction potential were identified according to the cyclic strength ratio and the cyclic shear stress ratio along the depth. The evaluation results agreed well with those from the dynamic geotechnical centrifuge model tests. This work provided an approach to accurately evaluate the liquefaction potential of the IOFs utilizing the variation of moisture content during shipping.