Numerical simulation of dynamic responses of semi-rigid rockfall protection barriers subjected to impact loading at different positions

To delineate the mechanics behavior of semi-rigid rockfall protection barriers, the energy dissipation mechanism of the system was investigated based on energy calculation theory and mechanics analysis, and an energy-based design method was introduced for the barrier. A semi-rigid rockfall protection barrier with a normal energy dissipating capacity of 100 kJ was then designed, and its efficiency was confirmed by a full-scale test. Deformation characteristics and force mechanisms of the system were studied to reveal the two-stage working characteristics of the system. Upon building a numerical model and validating it by comparing simulated and test results, parametric studies were conducted to investigate the dynamic responses of the barrier subjected to impact loading at different positions. The results showed that the impact location significantly influenced the dynamic behaviors of the barrier, including the maximum impact displacement, the deflection and stress distribution of the posts, and the failure mode. To consider the negative influence of impact positions compared to the standard test defined in EAD 340,059–00-0106, the amplification factors of key indicators were defined and the relevant values were recommended. The amplification factors of the maximum displacement, the maximum peak force of steel wire ropes, the deflection of steel posts at the impact point, and the bottom bending moment of the side posts were 1.23, 2.5, 1.06, and 1.5, respectively.