Abstract:Based on physical indexes such as density, moisture content, pore ratio, and plastic limit, the relationship between each physical index and soil vulnerability was analyzed. Undisturbed soil samples in Tongwei, Lanzhou, Baoji, Xiji, Xi'an, and other typical loess disaster sites were used as the research object. Through an indoor dynamic characteristics test and based on the findings of numerous previous studies, the regional effects of soil properties on geotechnical subsidence disasters were quantitatively analyzed. The results showed the following: (1) A positive or negative correlation exists between the seismic subsidence coefficient and individual soil physical property. The seismic subsidence characteristics in the west and east of the Liupan Mountain present a regional law: the disaster distribution is characterized as light in the south and heavy in the east under the same seismic load. (2) Over time, the increase in the number of human activities changes the soil moisture, increasing the overburden pressure of soil. Under the action of the overburden pressure of soil, the number of initial soil pores decreases, and the consolidation degree increasingly improves. Macroscopically, this result shows that the soil vulnerability is reduced, and thus, the seismic subsidence is reduced.