Effect of Freezing-Thawing Cycles on the Elastic Waves’ Properties of Rocks

Round 1

Reviewer 1 Report

In their submitted manuscript, the authors deal with the significant effect of freeze-thaw cycles on the structural stability of different types of rocks, by carrying out measurements of the velocities of the transmitted elastic P- and S- waves. In this sense, the manuscript falls within the scope of the journal, Geosciences.

In general, the manuscript is well written and comprehensive, the presented data is sufficient and the literature is adequate.

I suggest that the following improvements should be addressed before the publication of the manuscript.

1. It would be desirable to include a photograph depicting the experimental device for measuring wave velocities.
2. It would be desirable to include in a separate Figure, before Fig. 5, a few representative waveforms of the received signals for each type of rock.
3. In Figure 5, the units of frequency are missing.
4. Line 284: How did you calculate the spectral energy of the recorded signals? This is not mentioned in section 2.3. Please explain.
5. Furthermore, the quality of English should be improved all over the manuscript and several grammar, spelling and syntax mistakes should be corrected.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper present the results of seismic wave velocity variation after FT cycles for different rock types. The paper is interesting but it suffers of some problems related to the presentation of results and just qualitative comparison between rock types. The missing of porosity measurement is one of the main limitation since it allows only qualitative interpretation of the results. For these reason, I suggest major revision. In the following, a detailed list of the required changes.

Section 2.1

• The authors stated that they tested 7 rock types: marble limestone (line 74) are two different rock types. Is this rock a marble or a limestone? Then in the list provided in section 2.1 calcite is not cited. Please check it.
• The unit measure of density is wrong. It should be g/cm³. Better use SI unit measure: kg/m^3.
• It is better to summarise the average material characteristics (density, UCS and E) in a table, reducing the length of section 2.1.
• lines 90-91: provide (at least) reference values from literature.
• lines 100-101: not clear. Please rephrase.
• lines 126-128: not clear. The choice of cylindric samples don't allow the definition of anisotropies (if any) within the samples. Please address some comments.

Section 2.3: signal processing is commonly used in geophysics. I think that this section could be summarised by adding references, avoiding the use of well know equations. However, if the authors think that they are useful, all the equation components should be explained. 

Section 3:

• line 182: from the photo, this aspect is not so evident. It seems that dolomitic limestones are more fractured than other rock samples. 
• replace table 1 with a graph cycle number vs weight increment/decrease (W(cycle n)/W0) for a direct visualisation of the results. From mean values, it seems that most of the samples don't lose weight, remaining stable.
• Figure 3: for a direct comparison between each rock type, I suggest to graph all Vp values in one graph (and analogously Vs1 and 2). The use of a trend line could also help to graphically explain rock behaviour with temperature. Maybe, addressing a damage index both for seismic wave velocities and stiffness properties (Vagnon et al. 2019, 2021) could provide useful insights to address in the discussion. 
• Figure 4: why gneiss and sandstone are the most representative? I suggest to normalise E and poisson with respect to initial values of E and poisson and graph them for each rock type.
• Figure 5: title of the x axis is missing.

Discussion and conclusions: 

• lines 322 to 331: these lines are a repetition of lines at the beginning of the section. 

Suggested references:

• Vagnon F, Colombero C, Colombo F, Comina C, Ferrero AM, Mandrone G, Vinciguerra SC. 2019. Effects of thermal treatment on physical and mechanical properties of Valdieri Marble - NW Italy. International Journal of Rock Mechanics and Mining Sciences 116, 75-86.
• Vagnon F, Colombero C, Comina C, Ferrero AM, Mandrone G, Missagia R, Vinciguerra SC. 2021. Relating physical properties to temperature-induced damage in carbonate rocks. Géotechnique Letters 11, 1–11.

Author Response

please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Dear Authors,

I have read your revised version of the manuscript. All the requested changes have been addressed and the paper can be considered suitable for publication in the present form.

Best regards