Experimental and Numerical Study on a Grouting Diffusion Model of a Single Rough Fracture in Rock Mass
Round 1
Reviewer 1 Report
The paper reports a very reach study on the diffusion of grouting into fractured rock mass. Many things have been done but the first observation is on the lack of a good coonection between them. The reviewer opinion is that the data available and the approaches can be interesting but an effort has to be made to clarify what is the purpose of the reported study. I mean, what is the improvement in the knowledge of grouting in tunnels when they are excavated in rock masses. In particular, the study is devoted to the behaviour of a single fracture with 3 types of roughness. How the results can be extended to the rock mass? Furthermore, a reference to some of the roughness indexes usual used in rock mechanics could be very usefull, but: are the few tests performed by considering a particular (and not so realistic) geometry of the joint interface sufficient to infer conclusions of general interest?
Some questions/comments:
- How did you validate the results reported in the graph of Figure 4?
- How the roughness correction coefficient can be evaluated/estimated?
- To consider the roughness correction coefficient, that is referred to only geometrical observations, as an index that takes into account all the roughness effects of a rock joint is a too hard approximation! Are you sure that the roughness effect in a joint like the one reported in Figure 1 can be represented by a plane joint with an equivalent aperture? Can you explain and justify this choice?
- How do you take into account the small scale roughness (waveness) of a rock joint? This is an important factor to be anlysed or, al least, discussed.
- Did you analysed the influence of the smooth upper face of the discontinuity on the diffusion process of grouting?
- How many experimental tests did you perform? On line 264 you state "change in the grouting diffusion area with time are statistically calculated": what do you mean with "statistically"? How many diffusion traces did you analyse? Have you got a so big number of data to perform a statistical analysis?
- What is the influence of grouting mechanical and chemical characteristics on the results reported in the paper?
- Equation 12 has some typing problem.
In the reviewer's opinion the paper has to be revised and improved in order to aswer the previous comments and to better highlight its contribution to a better understanding of grouting behaviour both from a scientific and apllicative point of view.
Author Response
The authors are very grateful to the reviewer for helpful review comments and suggestions. In the attachment, we provide detailed point-by-point response to each review comment. Corresponding changes have also been made in the revised manuscript (with red highlight).
Author Response File: 
Author Response.docx
Reviewer 2 Report
All minor corrections are in the * .pdf file.
Generally, the article is written correctly. It contains both the interesting results of laboratory and numerical tests as well as theoretical basis. The minor suggestions in the review will improve the legibility, in my opinion, especially of the figures.
Comments for author File: 
Comments.pdf
Author Response
The authors are very grateful to the reviewer for helpful review comments and suggestions. In the attachment, we provide detailed point-by-point response to each review comment. Corresponding changes have also been made in the revised manuscript (with red highlight).
Author Response File: Author Response.docx
