Study of the deformation of blocky slopes under rainfall conditions

[panf7422-art]

I now wish to investigate the deformation behavior of landslides under rainfall conditions. As shown in the figure, boulders have been incorporated into the landslide model. Currently, I have only generated two components: the landslide soil surface and the boulder surface, and have set the material parameters for both. What conditions should be established to accurately represent the actual behavior of boulders within soil? In other words, should contact conditions be set between the boulders and the soil portion of the landslide? Thank you in advance.