This study aims to numerically analyze the dynamic responses and damage mechanism of the pile-slab retaining wall under the rockfall impacts by employing the refined finite element model. Firstly, the adopted numerical algorithm and material parameters in the simulation are validated by comparing the results of two impact modeling tests. Then, the full-scale model of a four-span pile-slab rock retaining wall conforming to the requirements of the specification is established. Furthermore, a series of numerical simulations are conducted to examine the dynamic process and analyze the failure modes of the structure under various rockfall impact conditions. The crucial indexes, including the impact force and reaction force of the structure, minimum principal stress of concrete, axial stress of reinforced bar, damage accumulation, and lateral displacement, are deeply explored. Significantly, the ratio between the rockfall impact force and the structure reaction force is adopted as a critical parameter to evaluate the resistivity of the structure. The results indicate that: (i) the ratio between the maximum rockfall impact force and the maximum structure reaction force on the pile as the impact center is larger than that on the slab; (ii) the minimum principal stress of the impact center is far greater than that of other areas; (iii) under the same impact energy, the structure reaction force, and pile top displacement are larger when the impact center is the pile; (iv) under the same impact energy, the local damage of slab is more serious when the impact center is slab. These considerations can finally contribute to the design of the pile-slab retaining wall.
 

rockfall, pile-slab retaining wall, numerical simulation, dynamic response, failure mechanism