Abstract: Based on slope monitoring project of Open Pit Quartz Mine of Jinchuan Group as background，with the use of the monitoring data，and taking local landslide of the beach as the research object，the deformation and failure mechanism of the slope under the stress concentration action caused by unloading effect is studied through analyze the cumulative horizontal displacement values of the monitoring sites around the beach and on the landslide.With RFPA strength subtraction method，the gradual instability process of typical profile and multi-steps during the mining process of 1 768 mm platform is reproduced.macro-cracks on the meso cycle of “rupture-stress transfer-rupture” is developed constantly，eventually forming a cut-through sliding surface.The strain localization phenomenon caused by stress concentration，release，and transfer process is accompanied by the whole process of failure.The monitoring results show that:the process of localized damage is migrated from mining step to the upper bench slope rock mass，and 7~11 m point of each beach slope is greatly affected by load transfer.

Key words: Slope, Strain localization, Strength reduction method, Monitoring, Data analysis