Seismic behavior analysis of soft and hard interbedded rock slope considering vibration deterioration of discontinuities at the interface between different rock types in meizoseismal area—a case study

The vibration deterioration of discontinuities with different joint wall material (DDJM) plays a vital role in the seismic behavior of soft and hard interbedded rock slopes under earthquake; however, too little work has been devoted to the subject due to lack of attention. In the present study, the seismic behavior of soft and hard interbedded rock slopes considering the vibration deterioration of DDJM was studied by taking the Shaba slope in China as a study case. A mathematical model quantitatively describing the strength deterioration of DDJM under strong earthquakes was established based on the results of the cyclic shear test, and the deterioration process was implemented by the FISH programming language in numerical software 3DEC. The deformation characteristics and supporting effects of the Shaba slope with the deterioration model were analyzed under seismic loads with different intensities. The results show that the maximum permanent displacements of the Shaba slope without supports obviously rise with the enlargement of seismic loads. Compared with results without considering the vibration deterioration of DDJM, the difference of maximum permanent displacements increases from 15 to 39.7% under seismic loads with intensities from VI to VIII degree. The existing supporting measures on the Shaba slope can not withstand the seismic load with intensities above VI degree and need to be optimized to prevent earthquake-induced disasters in the future.