Effects of weak interlayers on seismic performance of bedding slopes based on shaking table tests

Weak interlayers play a crucial role in the seismic performance of bedding slopes; however, the effects of structural surface development within these layers remain underexplored. This study presents two scaled models of bedding slopes, each with different weak interlayers: one with a homogeneous weak layer and another with discontinuous interfaces. Shaking table tests were conducted to compare their seismic performance. The results show that the peak ground acceleration (PGA) values above the weak interlayer in model A were significantly higher than those in model B, with the differences increasing as the input wave amplitude increased. The peak earth pressure (PEP) values at the tensile failure boundary at the rear edge of model A were also higher, whereas those within the weak layer at the toe of model A were lower than those in model B. Deformation analysis revealed that the maximum principal strain in model A initially appeared at the upper part of the tensile failure boundary, while the maximum shear strain was concentrated near the rear edge within the weak layer. In contrast, model B exhibited the opposite strain distribution. These findings provide insight into the impact of weak interlayers on the dynamic response and deformation of bedding slopes, highlighting the importance of considering this factor in seismic landslide investigations and failure mode predictions.