Abstract: Rainfall is an important factor in exacerbating rock slope disasters in open-pit mines,and accurate analysis of the acoustic-mechanical characteristics of rocks under the influence of rainfall is a prerequisite for implementing mining safety monitoring. In order to investigate the influence of rainfall on the stability and acoustic-mechanical properties of rock slopes in open-pit mines,this paper mainly uses indoor acoustic and mechanical tests as the main means to study the acoustic emission signal characteristics of sandstone during water saturation under different probe layout methods,and quantitatively analyze the acoustic emission characteristics of rock sample failure and its failure modes in dry and saturated states. Results show that: ① Rainfall significantly attenuates the acoustic emission signal,with a decrease of about 43. 3% in the maximum amplitude and about 33. 3% in the waveform frequency at all probe locations,exhibiting a significant " frequency shift" phenomenon; ② The acoustic emission events show a relatively random and mild manner in the process of dry rock sample failure,while they show a certain continuity and concentration in saturated rock samples;③ The failure mode of both dry and saturated rock samples is mainly shear failure,accompanied by some tensile failure,but the tensile failure in saturated rock samples is more obvi-ous. The study results can provide reference for the study of the sound-mechanical characteristics of rock slope in open-pit mines,and promote the application of microseismic monitoring technology in the stability monitoring of open-pit mine slope.

Key words: rock slope,rainfall,acoustic emission,acoustic-mechanical characteristics