The aim of the mini-symposium is to prompt synergy between researchers in the fields of granular mechanics and poromechanics. The topic will focus on model development and numerical techniques addressing multiple scales for granular materials and porous media. In recent years, increasing efforts have been devoted to reconcile the macroscopic continuum behaviour with the microscopic discontinuities inherent in granular and porous media. Models and numerical techniques have been developed in both communities to incorporate microscopic physics probed by either discrete simulation or grainscale experiments. It would be beneficial to provide a forum to exchange these ideas, which could lead to unifying theoretical frameworks or new methods in the respective fields.