Numerical simulation of dynamic response characteristics of structures impacted by rockfalls

Abstract:

In the disaster of impact of buildings （structures） by rockfalls， the shape of the rockfall is often uncertain， and the surface shape of buildings （structures） is also different. When a rockfall impacts a structure， its impact dynamic response characteristics are also different due to the different shape of the rockfall. The Explicit dynamic finite element method in ABAQUS finite element software is used to carry out the numerical simulation of the impact of structures with different surface shapes by rockfalls with different shapes， and the cushioning energy dissipation characteristics of different buffer layers are compared and analyzed. The results show that under the initial conditions of the same mass and initial velocity， when rockfalls with different shapes impact flat wall structures， the peak value of impact force becomes from large to small in the order as cube>cylinder （bottom）>cylinder （side）>sphere>triangular pyramid； when the impacting surface shape of the rockfall changes from “sharp” to “blunt”， the damage degree of the structure impacted by the rockfall will decrease， but the overall deformation area will increase； when the structures with different surface shapes are subject to rockfall impact， the peak value of impact force is in the order of plane shape>convex shape>concave shape>wavy shape>inclined shape. The inclined structure has relatively better rockfall impact resistance. Through comparative analysis of the cushioning and energy dissipation characteristics of rockfall impact when different buffer layers are set in front of the structure， it is concluded that the EPS sand composite cushion has good cushioning and dissipation performance， and it has a broad application prospect in the actual rockfall disaster protection engineering.

Key words:rockfall shape;structure shape;buffer layer;impact force;dynamic response characteristics;geological hazards