Mechanical and hydraulic properties of the excavation damaged zone (EDZ) in the Opalinus Clay of the Mont Terri rock laboratory, Switzerland

Hale, Sina; Ries, Xavier; Jaeggi, David; Blum, Philipp

doi:https://doi.org/10.5194/se-12-1581-2021

Articles | Volume 12, issue 7

https://doi.org/10.5194/se-12-1581-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/se-12-1581-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 12, issue 7

Research article

|

13 Jul 2021

Research article |

| 13 Jul 2021

Mechanical and hydraulic properties of the excavation damaged zone (EDZ) in the Opalinus Clay of the Mont Terri rock laboratory, Switzerland

Sina Hale, Xavier Ries, David Jaeggi, and Philipp Blum

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Final revised paper (published on 13 Jul 2021)
Preprint (discussion started on 05 Feb 2021)

Interactive discussion

Status: closed

RC1:
'Comment on se-2021-4', Zeynal Abiddin Erguler, 06 Feb 2021
Dear Authors,

Please be informed that I read carefully your manuscript. I would like to say that the content and outputs of your research are very important for scientists investigating fracture closure and self-sealing of mudrocks. I have only below given minor comments on your manuscripts:

Lines 16 and 403: The needle penetrometer cannot be used for geophysical characterization of rock materials. Only mechanical properties can be predicted by this index test. I suggest authors do not trust too much on predicted geophysical values and so the related empirical approaches of previous studies. Actually, you do not need these predicted parameters for this manuscript. Please apply proper modification

The introduction part is very long and so it is very hard to see the main motivations of this study. This part should be shortened. Since there are many previous studies on physical and hydro-mechanical properties of Opalinus Clay, the contribution of this study should be more strong to convince readers to read the entire paper.

Some of relationships given in Figure 6 (Fig 6c,d, f, g, h, and i) are not statistically significant. I recommend removing them.

The manuscript looks very long. It would be a little difficult to read without getting bored for those who do not work on this subject. Please shorten your manuscript by removing unnecessary evaluations, discussion and outputs of previous studies.

Except for the discussion on predicted P-wave and S-wave velocities, the content of this manuscript looks interesting. So I recommend minor revision for this submission.

Regards

Zeynal
Citation: https://doi.org/10.5194/se-2021-4-RC1
- AC1: 'Responses to comments by Reviewer #1 (se-2021-4-RC1)', Sina Hale, 01 Apr 2021
  
  Please find our responses to se-2021-4-RC1 in the Supplement (se-2021-4-AC1).
  
  Citation: https://doi.org/10.5194/se-2021-4-AC1
RC2:
'Comment on se-2021-4', Anonymous Referee #2, 11 Mar 2021

see attachment

Citation: https://doi.org/10.5194/se-2021-4-RC2
- AC2: 'Responses to comments by Reviewer #2 (se-2021-4-RC2)', Sina Hale, 01 Apr 2021
  
  Please find our responses to se-2021-4-RC2 in the Supplement (se-2021-4-AC2).
  
  Citation: https://doi.org/10.5194/se-2021-4-AC2
EC1:
'Comment on se-2021-4', Virginia Toy, 22 May 2021

SE-2021-4 Topical editor recommendations
I have read over the referee comments, and your responses, and also checked the changes you made to the manuscript. I mostly think you've done a good job of addressing their concerns, and I find the manuscript to be scientifically sound and worthy of publication. However, there are a couple of places where I recommend you do a little bit more work to adequately address the reviewer's comments and further improve the manuscript, as follows:
I would re-write your revised intro sentences as follows:
“Hence, the objective of this study was to investigate the hydro-mechanical properties of the EDZ in the Opalinus Clay of the Mont Terri URL from in situ measurements on the exposed rock surface. We carried out a nondestructive and holistic determination of hydraulic and mechanical parameters of the fractured rock mass around a small tunnel, by combining transient-flow air permeametry, photomicroscopy, and needle penetration tests. We characterised bulk rock properties of the claystone, and quantified mechanical and hydraulic apertures of different fracture types of the EDZ, since these discontinuities can significantly control the overall material behavior. We have also explored alteration of a non-lined niche that was directly exposed to air for several years .... and then say WHY and HOW you did this.
Reviewer 1 criticised inclusion of discussion of the P and S wave velocity. You did not respond to their comment. Please provide some sort of response.
Reviewer 2 criticises the statistical basis of the conclusions your reach about the EDZ fractures because your analyzed dataset is very small. You don’t acknowledge this small dataset well enough in the current conclusions. Please add a statement about this.
THMC at line 47. The reviewer’s point was that you never define the full term, just go straight to the acronym. You must give the full version here too.
Line 142: I don’t find your revision clear enough. Why not just clearly say ‘within the first 1.3 m depth into the niche’?

Citation: https://doi.org/10.5194/se-2021-4-EC1
- AC3: 'Responses to Topical editor recommendations (se-2021-4-EC1)', Sina Hale, 28 May 2021
  
  Please find our responses to se-2021-4-EC1 in the Supplement (se-2021-4-AC3).
  
  Citation: https://doi.org/10.5194/se-2021-4-AC3

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

AR by Sina Hale on behalf of the Authors (29 May 2021) Author's response Author's tracked changes Manuscript

ED: Publish as is (10 Jun 2021) by Virginia Toy

ED: Publish as is (10 Jun 2021) by Federico Rossetti (Executive editor)

AR by Sina Hale on behalf of the Authors (11 Jun 2021)

Short summary

The construction of tunnels leads to substantial alterations of the surrounding rock, which can be critical concerning safety aspects. We use different mobile methods to assess the hydromechanical properties of an excavation damaged zone (EDZ) in a claystone. We show that long-term exposure and dehydration preserve a notable fracture permeability and significantly increase strength and stiffness. The methods are suitable for on-site monitoring without any further disturbance of the rock.