Abstract:

Under the condition of rainfall，due to the infiltration of water and the change of soil bulk

density，the stability of dump slope is challenged.Based on the Van Genuchten model and Morgenstern

Price method，the saturated-unsaturated seepage field of the case dump under rainfall conditions is ana⁃

lyzed. Considering the matric suction of waste rock soil，the influence of rainfall on the stability of the dump

slope is studied.The results show that the stability of rainfall conditions in the saturated-unsaturated state is

complex，and the influence of rainfall on the seepage field of the dump in the unsaturated state has an obvi⁃

ous lag process.When the rainfall is just over，a local transient saturated zone will be formed in the slope un⁃

der the infiltration of a small amount of rainwater.After a period of rainfall，the amount of rainwater infiltra⁃

tion in the slope increases，the range of transient saturated zone shrinks，and the local groundwater level ris⁃

es.The minimum safety factor of slope stability does not correspond to the time state of the highest saturation

line under rainfall conditions. The decrease of matric suction in unsaturated medium has obvious influence

on the stability of dump slope.

Key words:

dump, slope stability, saturated-unsaturated soil, matric suction