Effects of rockfall shape on deformation performance of ground reinforced embankments subjected to lateral impact

Ground reinforced embankment (GRE) is an economical and efficient protection measure against rockfalls. In various design guidelines of ground reinforced embankments, the impact force of the rockfall is the principal factor, which is significantly affected by rockfall shape. This article conducts real scale tests and numerical tests to observe the external deformation behavior and the internal dynamic response of GREs subjected to lateral impact. Five shapes of the rockfalls corresponding to three contact types are set up in the tests. The experimental results show that the impact surface shapes of the rockfalls govern the penetration deformation patterns of the embankments, and the deformation extent of the disturbed soils. For different contact types between rockfalls and construction materials, the failure mode of the geosynthetics and the displacement distribution of the disturbed soils are distinguishing. The disturbed soils can be divided into two parts, the part surrounds the rockfall mainly expands laterally, and the rest is extruded and slips backward. Basically, the sharpness of the rockfall results in the deeper penetration and the smaller impact force. The influence of the rockfall shape needs to be carefully considered in the design of ground reinforced embankments.