In this paper we find a comprehensive, detailed and comparative analysis of the technical measures taken in case of rockfalls along the roads. Thus, an optimised model is proposed versus a current model designed to provide complete protection of roads, namely flexible barriers. This research is qualitative and will form the basis of a quantitative analysis that will further investigate factors that negatively influence the performance of flexible barriers, such as: slope topography, rockfall shape, attack angle, system installation morphology etc. The investigation was based on a rockfall disaster case in southwestern China. It analysed flexible barriers in terms of dissipated kinetic energy and found that the proper assembly relationship is essential during their installation in the field. The benchmarking methods and findings are a suitable guide for improving the reliability of flexible rockfall barriers and I strongly recommned this paper to be published.

In this work, the authors proposed a design of flexible barriers subject to rock impacts is to optimize its withstanding to the impact. To this end, they, starting from the rockfall event occurred on November 2020 in the Chongzhou where a rockfall damaged significantly the flexible barriers, performed numerical simulations to reproduce the event and to improve the quality of them.

After in situ survey, where they analysed the damage processes, the authors carried out rockfall simulations to evaluate the kinematic variables of the block at the impact and performed two distinct numerical simulation series to: (a) reproduce the event and the obtained damage (b) assess the performance of the their designed barrier.

For this reason, this work is very interesting because it analyses the process occurring during the impact between the rock and the barrier affecting the design procedure.

In this review, the following remarks are proposed:

Line 52: please specify what you mean with damage characteristics.

Line 73: the sentence “This paper provides …” is not clear, please rephrase;

Line 85: Bentley 2021: the year is different from the reference. Please correct one of it;

Line 161: Please rephrase the sentence “… rockfall was simulate to “,. “… rockfall was used to “.

Line 165: What do you mean “were in line with”?

Line 168: what do you mean with “10,000 computation cycles”? Do you refer to 10,000 block movement was simulated?

Line 504: Yu et al. (2019a) is in the reference list but the authors did not cite in the manuscript. Please remove it.

In general in the text the acronyms are note specified please add a figure or a table specifying the meaning of them, otherwise some figures and some text portion are not understandable. Furthermore, it is need a table to specify the model parameter values used in the numerical simulations.