Analysis of swallowtail mutation instability of slope with weak interlayer under blasting disturbance

Abstract

Abstract The stability analysis of slope under blasting disturbance is one of the important research topics in blasting engineering and geotechnical engineering. Based on the dynamic instabil-ity mechanical model of slope with weak interlayer, the mechanical effect of blasting dis-turbance on slope system is analyzed. The swallowtail mutation model of slope system under blasting disturbance is established. Two methods to determine slope stability under blasting disturbance are proposed: safety factor method and double judgment method. Through the analysis of the dynamic instability mechanism of the slope system under the effect of blast-ing disturbance, it is concluded that: (1) the greater the amplitude of blasting disturbance vibration, the worse the stability of the slope system, and the greater the possibility of land-slide disaster. The slope landslide disaster caused by blasting disturbance mainly occurs in the middle and late stage of blasting disturbance (0.17 ∼ 0.5s). (2) When the period of blast-ing vibration wave (T > 1s), the frequency of blasting disturbance wave can be appropriately increased, which is conducive to reducing the impact of blasting disturbance on slope stabil-ity. When the period of blasting disturbance wave (T < 1s), proper adjustment of blasting disturbance frequency will not have a direct impact on the stability of slope. (3) With the increase of the incident angle of blasting vibration wave, the change of the dynamic self-stability critical height of the slope system shows a trend of increasing, and the in-creasing rate is decreasing. The greater the incident angle of blasting vibration wave, the worse the stability of slope system. Proper reduction of the incident angle of blasting vibra-tion wave is beneficial to improve the stability of slope system. Finally, the rationality and applicability of thse proposed double judgment method are verified based on the actual con-ditions of the current slope in Laoyingzui.