Comprehensive investigation and analysis of liquefaction damage caused by the Ms7.4 Maduo earthquake in 2021 on the Tibetan Plateau, China

Soil liquefaction due to earthquake activity can cause serious disasters, and post-earthquake investigation is the most direct means of understanding liquefaction issues. In this study, a rare large-scale liquefaction event that occurred at a high altitude of 4,200 m on the Tibetan Plateau in 2021 due to the Ms7.4 Maduo earthquake is systematically investigated and analyzed. The macro phenomenon, geology, geomorphology, and geotechnology of the liquefaction zones are presented and compared with previous knowledge. The distribution characteristics of the seismic ground motion in the liquefaction zones is obtained and compared with the current understanding of the triggering conditions of liquefaction. Through comparison with field observations, the applicability of the existing two typical liquefaction evaluation methods is analyzed. Through analysis of a representative bridge failure event that occurred during this earthquake, the deficiency of the currently used specifications for liquefaction discrimination are revealed. The investigation and analysis results of this study on a historically rare liquefaction event are of significance for improving our knowledge of liquefaction caused by earthquakes and for developing liquefaction hazard reduction techniques.