Abstract: The dynamic response and stability analysis of tailings pond under earthquake is an important part of the safety evaluation of tailings pond,but most of the current studies only consider the horizontal seismic action,which is dangerous for first-class and second-class tailings pond and does not meet the requirements of national norms.For this reason,taking a sec ond-class tailings pond as an example,the seepage field and stress field of tail-ings pond under normal water level and flood water level are analyzed by using SEEP/W and SIGAM/W modules in Geo-studio software to consider fluid-solid coupling. Then,the dynamic response and vibration liquefaction of the tailings pond under the combined action of horizontal and vertical earthquakes are studied by using QUAKE/W module.Finally,the stability of tailings dam under different working conditions is analyzed and calculated based on the limit equilibrium method in SLOPE/W module.The results show that:① Although the buried depth of the infiltration line in the dam body rises under the condition of flood water level,it still meets the requirements of the code;the maximum horizontal displacement of the tailings dam is concentrated in the middle of the dam slope,while the maximum vertical displacement is concentrated on the top of the accumulation dam.② Under the action of earthquake,the tail ing dam will have "whiplash effect","delayed effect" and "elevation effect",and the liquefaction area of tailings pond under the action of unidirectional seismic wave is smaller than that under the action of corresponding bidirectional seismic waves,and the horizontal seismic wave has a great influence on liquefaction,which shows that it is necessary to consider the joint action of horizontal and vertical earthquakes at the same time.③ The limit equilibrium analysis results of the stability of the tailings damshowthat thestabilitycoefficientsmeet therequirementsof thecode,andthetailingsdamisstableasawhole.

Key words: tailingspond,Geo-studiosoftware,bidirectional earthquakewaves,liquefaction,stability