Numerical methods based on Lagrangian framework, such as FEM, have widely used in order to predict the deformation of geomaterials. Large deformation, however, induces a significant numerical error due to the distortion of numerical mesh in Lagrangian scheme. A CIP-based numerical method for large deformation problems of geomaterial is proposed in a series of this study. In the method, geomaterials are assumed to be a fluid that has shear strength based on the Mohr-Coulomb's failure criterion. From previous study, effectiveness of the numerical method was validated using results of real phenomena and model test. The efficacy of proposed method for interaction problems between solid and geomaterials, however, is not investigated in detail. In order to describe the interaction between geomaterials and rigid body, the numerical method is modified and some numerical simulations are conducted in this study. The effectiveness of the modified method for interaction problems is discussed based on numerical results.