Abstract: According to the reality of Dayanggou Dump of Gongchangling Open Pit Iron Mine，and on the basis of the geotechnical engineering investigation and the analysis of physical and mechanical properties，the stability of typical sections of dump slopes under the current operating status and the limiting dump height operating status was analyzed with the use of Geo-Slope limit equilibrium theory and FLAC2D numerical analysis method. The results showed that the Dayanggou dump slope is stable under the current operating status. Under the limiting dump height operating status，the dump slope keeps stable when the dumping reaches the limiting height of 436 m. This conclusion is great significant for the actual dumping.

Key words: Dump, Stability, Weak layer, Numerical simulation