Using methods such as time history analysis

finite element limit equilibrium method

and sliding body deformation analysis

focusing on the phosphogypsum dam of a high-stack tailings storage facility in Yunnan province

by analyzing the dam′ s changes under static and dynamic loading conditions

this study investigates the dynamic response

permanent deformation and stability mechanisms of the phosphogypsum dam under strong earthquakes. As well

the factors affecting the stability and the temporal variation of the safety factor of phosphogypsum dam under seismic loading are studied. The results indicate that the distributions of vertical stress

horizontal stress

shear stress and the total stress in the dam before earthquake are reasonable. During earthquake

the instantaneous safety factor of the phosphogypsum dam exhibits a characteristic of fluctuating reduction but does not reach the extreme amplification caused by whiplash effect

suggesting that the seismic performance of the high- stack phosphogypsum dam meets the corresponding seismic design requirements. In evaluation of the overall safety of the phosphogypsum dam

it is necessary to consider the performance of different zones of the dam under both static and dynamic conditions

as well as the potential impact of beyond design basis earthquakes on the acceleration of dam crest

to ensure the overall safety of the phosphogypsum dam. This study provides a theoretical basis for enhancing safety and stability of phosphogypsum dams and offers technical support for management of similar projects.