Dr. Xue-Qian Ni is an Assistant Professor and Master Supervisor in the Civil Engineering College at Central South University in China. She was a visiting scholar at Nagoya Institute of Technology in 2019 and obtained her Ph.D. from Tongji University in 2021. In addition to her academic roles, she serves as a councilor of the Hunan Society of Geohazard Prevention and Ecological Restoration, and is an editorial board member of the international journal ‘Journal of Testing and Evaluation’. Her primary research interests include the mechanisms and prevention of soil liquefaction/reliquefaction disasters, geotechnical laboratory testing, numerical analysis using the discrete element method, and seismic engineering in seasonal frozen soil. Based on the existing research findings, Dr. Ni hosted four national and provincial-level research projects and participated in six projects, including the National Key Research and Development Program. Furthermore, she has contributed to the publication of nearly 30 high-quality papers.

Brief Introduction to the Report

Field investigation showed that sandy soil that had already experienced liquefaction in the main shock would liquefy again during the aftershock, which was known as reliquefaction. In some areas, the damage from reliquefaction during aftershocks was more severe than the first liquefaction damage, as observed in events like the 2010–2011 Canterbury earthquake and the 2011 Great East Japan Earthquake. This study aimed to clarify the key factors influencing reliquefaction resistance and explain why sand can undergo liquefaction again in subsequent aftershocks with lower vibration amplitudes. A new evaluation index for reliquefaction resistance was introduced. Additionally, the study delved into the mechanism of multiple liquefaction occurrences in clayey sand under mainshock-aftershock sequences, revealing the dominant factors. These findings contribute to a deeper understanding of liquefaction mechanisms and provide vital scientific insights for evaluating and mitigating the recurrent liquefaction of soil.