Mechanisms and Models of Attenuation of Shock Waves through Rock Formations

Round 1

Reviewer 1 Report

Dear authors, I had some trouble with the english in your text. Especially with the introductory part and the literature review. For example, page 2, line 47 to 53 doesn't seem to be proper sentence to me. But the whole section is nearly incomprehensible with incomplete sentences and no real flow of thought, from one point to the next.

I'd like to remark on your opening sentence: I don't think that the passing of time necessitates more mines, rather that this is due to growing time. Similarly, technological advancement doesn't seem to have a direct link to a need for deeper mining either.

Please introduce what "UDEC" is, and add a reference for it.

The presentation of the setup and simulation result is also confusing to me. You write about a 100 m area, but 100 m is a length, not an area. It is not quite clear, why the rock deformation increases between 40-60 m, which you note as obvious. There seems to be a connection between the letters in the setup description in Figure 4 and the subsequent result illustrations, but this doesn't seem to be explicitly stated in the text. Are the points indicated in Figure 4 corresponding to the points of measurement you later on talk about?

Why is the deformation for A in the steps 0-500 different in Figure 7 then in Figure 8? What are the grid lines in Figure 6, is this the computational grid?

Why is the dynamic simulation stopped before a stationary state seems to be reached?

Please introduce the meaning of all the symbols in your equations.

In Figure 10 it is hard to make out the cable axial forces on top of the stresses, maybe a different color-scheme for the stresses would by useful? Possibly a greyscale to contrast with the colored axial forces.

In line 313 you refer to sigma_0, which isn't used in the equations.

Line 322 refers to the inequality relation in equation 4, but equation 4 doesn't state an inequality relation.

It didn't become quite clear to me, how the UDEC simulation relates to the subsequent attenuation modeling you subsequently describe. Could you try to state this more clearly, please?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Minor spelling mistakes:

Table 1 Shear unit should be GPa instead of Gpa

Friction angle unit (ri) what is the unit(ri)

 

In what units are Effective stress shown in Fig. 6. If they are Pascals, it would be better to use MPa, i.e. instead of -4.0000E+7 Pa, it would be -40 MPa. Same but better readable. Similarly in Fig. 10 a and b.

And in Fig. 10c and d, it would be more advantageous to present the force in kN.

No actual shockwave attenuation factors measured in actual rock formations.

Author Response

请参阅附件。

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear authors, thanks a lot for addressing my points and your patience. I think the text has considerably improved. However, I still have some objections and remarks.

ad point 1:

I have trouble understanding this sentence:

From the last century, there are many scholars through theoretical calculation and computer simulation to analyze the mechanism and model of rock burst.

Is it missing som part? Maybe it should read "... there are many scholars that have tried to assess the process through theoretical calculation ..."?

Then there are still repeatedly weird constructs like this:

Dou et al[18–20].a strain-softening numerical model based on the Hoek-Brown failure criterion was developed to evaluate the destressing efficiency of RDHB in selected underground coal mines.

Is the reference refering to the sentence before? Why is there a period after it with lower case "a" following it immediately. Maybe that sentence should rather be: "A strain-softening numerical model based on the Hoek-Brown failure criterion was developed to evaluate the destressing efficiency of RDHB in selected underground coal mines by Dou et al[18-20]."?

There are many more similar constructs throughout that paragraph.

ad point 3:

Figure 3 shows distance of coal wall. Distance is a length: why do you refer to it as an area? Shouldn't it be 100m distance, or the area up to a distance of 100 m?

ad point 4:

You write:

The velocity curve in Figure 8 is an excerpt of a waveform from seven monitoring points A to G in Figure 7

I was not referring to the velocity curve in Figure 8, which isn't shown in Figure 7. But looking at the shape of the time signal for the displacement at point A there seems to be big, qualitative difference between Figure 7 and Figure 8. In Figure 8 the signal flattens out after 250 time steps, while in Figure 7, there is another oscillation period.

ad point 5:

If the unbalanced forces are small enough, the displacements should also settle, however your time series still show a gradient there with ongoing deformations? Also the waves still seem to have comparably large amplitudes. Are you sure that those 3000 steps are sufficient to capture the dynamics of the attenuation behavior? Could you include the reasoning for that in your presentation?

ad point 7:

The colored axial stresses are still hard to distinguish from the colored background in figure 10 in my opinion. If you want to present those forces to the reader, as you do in the text, I think it would be good to make them better visible. I don't see how your elaboration addresses this point.

ad point 10:

I don't understand how your elaboration answers my question there. You present the detailed numerical analysis with UDEC, and after that you describe a simpler model for this system. Is there any relation between the former and the latter? This doesn't really get clear in your presentation, I am afraid.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf