抄録
A huge number of boulders rest on slopes along the railway. In an attempt to evaluate the degree of rockfall risk of these boulders effectively and quantitatively, basic experiments, together with eigenvalue analyses by 3-D FEM, were performed for revealing the vibration characteristics of the rigid bodies simulating boulders. When the natural frequency of the rigid body, together with its shape exposed above the ground level and the ground strength, is known, the in-soil penetration depth of the rigid body may reasonably be estimated.
