Blasting response and stability evolution of high slope in open-pit mine subjected to rainfall infiltration

Rainfall and blasting are the main factors inducing landslide on open-pit slopes, however, the combined effect of both factors on the slope stability remains insufficiently understood. In this study, the secondary development of the seepage module is conducted using FISH language in the FLAC3D software to calculate unsaturated seepage. Focusing on the high slope of Dagushan open-pit mine, the responses of horizontal velocity and displacement at the slope monitoring points under different rainfall intensities is investigated. Additionally, the variation of the slope safety factor following blasting at different times during rainfall under the same daily rainfall is examined. The results indicate that the rainwater infiltration reduces the strength of rock mass and increases sensitivity to blasting, as evidenced by the gradual increase in peak velocity and displacement. Once the rainfall ceases, the peak velocity gradually returns to its initial state, while the peak displacement stabilizes at a steady value. Rainwater infiltration has a significant negative impact on the slope stability following blasting. As the daily rainfall increases, the required time between the cessation of rainfall and the resumption of blasting operations progressively lengthens.