On seismic response of loess-mudstone slope with underlying anti-dip fault zone: laboratory investigation using shaking table test

Fault zone often contributes to occurrence of loess-mudstone landslides in Western China under earthquake loads. As compared with extensive knowledge in literature about the effect of bedding fault zone (BDFZ) on the dynamic response of loess-mudstone slope (LMS), the mechanism to account for the dynamic response of slopes with an anti-dip fault zone (ADFZ) remains unclear. In this study, we conducted a laboratory investigation using a shaking table test on LMS with an ADFZ and compared the effect of ADFZ with BDFZ. The typical acceleration response is that the acceleration amplification factor (AAF) increases from the bottom to the top of the LMS surface and is larger in loess than in mudstone. The peak acceleration of 0.3 g is critical to slope seismic dynamic response and failure. Unlike the slope with BDFZ, the slope with ADFZ showed a marked acceleration amplification in the fault zone and the hanging wall. The peak dynamic earth pressure in the fault zone is slightly smaller than in the strata on both sides. Seismic cracking is the failure pattern of LMS with ADFZ. The outcomes of this study provide a scientific reference for the risk assessment and seismic design of LMS with fault zone.