ABSTRACT
This chapter presents a suggestion to a quantitative model for vulnerability assessment of structures hit by debris flow, where the vulnerability is measured by the probability of reaching a certain damage state. The method is based on the premises that the debris flow is not so large as to completely wipe out the structure, but impacted by a force, which leads to structural vibration and results in a specific state of damage. As debris flow impacts a structure it sets the structure in vibratory motion. The chapter provides a simple method for prediction of damage in a structure impacted by a debris flow of known magnitude. The vibrations from an impact will damage a structure in approximately the same way as a ground vibration will damage a structure standing on the ground. From this it may be assumed that a debris flow impact force, modelled as an impulse, may be compared to ground acceleration from an earthquake.
