Abstract：A 5.7-magnitude earthquake was recorded in Songyuan of Jilin province on May 28, 2018, and a large range of typical and rare sand liquefaction was observed in the epicenter of the earthquake. To ascertain the earthquake damages and site characteristics, field survey and experimental testing (including boring sampling, standard penetration testing, wave velocity testing and cone penetration testing) were performed, so that the causes and influence factors of sand liquefaction occurred in this earthquake can be preliminarily analyzed. The liquefaction covered a total area of 80km2. Macroscopically, sand boil and water sprouting in paddy field could be observed, without large-scale collapses of structure occurring. Within the range, the distribution of soil layers is relatively unitary, and the liquefaction distribution is mainly affected by those factors such as ground motion, landform and groundwater level. The depth of liquefied sand layers was mainly within 10m, and the liquefaction rising passage of deep sand layer with a burial depth of about 17m was disclosed by drilling, indicating that the evident deep-layer sand liquefaction phenomenon occurred in this earthquake, but this phenomenon was often ignored in the site investigation of earthquake. Cone penetration test possesses certain superiority in identifying the layer of liquefaction and attaining the physical and mechanical parameters of soil layers, and shall be suitable for the site survey after earthquake. Furthermore, there is a risk of larger-scale sand liquefaction occurring in Songyuan city. The sand liquefaction hazard in this area shall be specially studied in those projects of earthquake prevention and disaster mitigation planning as well as engineering survey and design.
