A study of the influence of the crossing-slope fault geometry on the slope seismic response

Compared with the landslides in the general gravity environment, the earthquake-induced landslides are significantly different in formation mechanisms and kinetic characteristics. Under the normal and rainfall conditions, the fault fracture zone, as the discontinuous structural plane of the slope, often adversely affect the stability of the slope. Under the earthquake condition, the fault fracture zone within the slope has a limited filtering effect, which could weaken the seismic response of the slope. To investigate the influence of the reverse fault’s geometry on the slope’s seismic response, we took the Niumiangou landslide, the Woqian landslide, the Xiejiadianzi landslide and the Donghekou landslide as reference objects and generalized the geological model of the fault-crossing landslide in this study. The seismic response of slopes with faults of different widths, dips and positions are simulated using the 3DEC discrete element software. The simulation results show that (1) as the fault dip angle increases, the peak value of the total displacement of the slope and the peak acceleration of the slope surface show an increasing trend, and the slope stability is worse. (2) The peak acceleration of the monitoring point at the top of the slope is generally greater than that at the bottom and waist of the slope. As the width of fault fracture zone increases, the effect on the seismic response of the slope becomes obvious.(3) The presence of faults facilitates the probability of slope instability. When the fault is located at the top of the slope, the variation of the seismic response with the dip angle and the fault width shows a more obvious regularity. This study can provide a theoretical basis for further revealing the impact of fault fracture zone on the stability of slopes under the earthquake condition.