斜面崩壊にともなう物質の移動過程  [in Japanese] Transport Processes of Debris Mass Produced by Slope Failure  [in Japanese]

Recent studies on motion of debris mass produced by slope failures were introduced mainly from view point of dynamics. Various features of slope failures bring about different material components, structures and initial conditions of motion of the mass, but dynamical behaviour of moving mass after some motion is almost common in dependently of initial starting state and can be treated quantitatively according to dynamical of fluid dynamical equations. Motion of debris mass accerelating along a steep slope and decerelating along a gentle slope can be explained approximately with the mass point model including gravity, dynamic friction and dynamic drag terms. One result of the dynamic analysis shows that larger mass can run out along longer path. Flow patterns of a mixture of debris particles and fluid can be explained by Bagnold's grain flow model adding a shearing stress term in fluid part. Change in volume, shape and components of moving debris mass during the motion along slope makes the motion analysis very difficult. Cooperative works between physical and geological scientists are needed to study slope form change and to estimate dangerous area from landslides hazard.