Abstract: In order to investigate the impact of blasting vibration and structural surface damage on slope stability and the stability coefficient variation and undermining mechanism during blasting process, the research gets the law of the shear strength variation during under mining process with the degradation mechanism for shear strength in structural surface as the basis. In combination with the mechanism of blasting dynamic loading, calculation formula of both sliding and sliding resistance forces under the condition of fixed vibration were corrected. The calculation methods of timeliness stability coefficient for planar and folding landslide models are deduced and applied to the study of the north slope stability at Haerwusu Surface Coal Mine. The results show that stability factors are 1.348 and 1.173 for intact structural surface and damaged structural surface respectively. In addition, the slope stability coefficient decreases linearly during the slope undermining progress while the decreasing speed is proportional to the cohesive force C. Furthermore, under the action of blasting vibration, the slope timeliness stability fluctuates up and down in response to seismic acceleration and the combined influence of both blasting vibration and structural surface damage makes the slope timeliness stability present a descending trend when fluctuating.

Key words: blasting vibration, structural plane, progressive failure, stability, dynamic load