Lumped Mass Damper Model to predict the acceleration process of a rockslide from a steady state movement to the final failure stage

The Lumped mass damper model (LMDM) is a model to predict the landslide moving velocity, with a clear slip surface including rockslide, in the primary creep to the secondary creep stage of the landslide movement. However, in the current LMDM, when the landslide movement velocity increases, and enter the third order creep stage, the velocity of LMDM deviate from the actual displacement amount step by step. Therefore, in order to solve this problem, we designed a model considering 'reduction of friction coefficient' or 'decrease of Cd' with increasing velocity. As a result, it was found that landslide displacement up to the final failure stage can be predicted. We describe this method and report its physical meaning. In addition we mention to Tank Model on LMDM.