地质科技通报 (Mar 2024)
Discrete element simulation of the dynamic response and instability process of the Xinhua Village landslide in Baoxing County under the "6.1" Lushan earthquake
Abstract
Objective The shallow potential sliding layer of a slope is an important feature in seismic geological disasters. Its characteristics, such as slope shape and slope structure, tend to complicate the dynamic response and slope damage. Methods In this paper, the landslide in Xinhua Village, triggered by the Lushan Ms 6.1 earthquake, is taken as a case study, and two-dimensional discrete element computational models are developed based on a field investigation. The dynamic response and simulate instability are investigated by comparing numerical simulations of homogeneous and heterogeneous models, representing pure terrain and a shallow potential sliding layer, respectively. Results The findings are as follows: (1) The potential sliding layer at the shallow surface of the slope exhibits significant dynamic amplification, which typically increases nonlinearly with height; (2)The slope surface shape has an obvious influence on the slope amplification effect.In the convex part, the amplification effect of the horizontal and vertical acceleration of the slope surface is significant, while the amplification effect of the concave part is lower than that of the convex part; (3) In the Xinhua Village landslide, the convex terrain is destroyed before the concave terrain under the effect of micromorphology, and its instability process is divided into five stages, namely, local seismic cracking of vibration amplification, convex terrain destruction, concave terrain destruction, complete destruction of the overall slide and gravity accumulation. Conclusion The research results are helpful for deepening the understanding of potential unstable slopes induced by earthquakes and shedding light on disaster prevention and mitigation.
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