Sand- and Clay-Photocured-Geomembrane Interface Shear Characteristics Using Direct Shear Test
Round 1
Reviewer 1 Report
Minor comments:
Point 1: Since all authors are from the same institution, the superscript at each author's name is not necessary. Please verify with the instructions for authors.
Point 2: Use en dash instead of a hyphen when indicating a range of numbers. A hyphen is used for joining two words or two parts of words together.
Point 3: Be consistent with the use of the word "photocured" throughout the manuscript. I noticed that sometimes the word "light-cured" is used. Also, be consistent using the word "photo-curing." I noticed that it appears sometimes as "photocuring" in line 92 and "photo curing" in line 115.
Point 4: Abbreviations (i.e., UV, DEM, HDPE, GMB, and ADI) must be spelled out completely when they appear first in the manuscript and be used consistently throughout the manuscript.
Point 5: In the reference list, the volume number (and issue number if available) (for journal articles) must be italicized. Please verify with the author's instruction. In line 384, the friction coefficient symbol "f" must also be italicized.
Point 6: Use round brackets in figures and tables to indicate the unit of measurement for a given scale instead of a forward slash.
Point 7: In Table 1, I recommend adding one more column for the percentage range per material used in the study (except for the monomers).
Point 8: In Table 2, I recommend removing the percentage sign next to the numerical values since the header indicates it already.
Point 9: In Table 3, since specific gravity is a unit weight or density ratio, then it must be dimensionless.
Point 10: Figure 1 is not mentioned and not explained well in Section 2 of the manuscript.
Point 11: I recommend combining Figures 2–4 into one figure (i.e., Figure 2) with assigned subtitles (i.e., 2a–2c).
Point 12: I recommend removing Figure 6 as long as the material production procedure in Sub-section 3.2 is improved. The chronological order is missed from line 151 through line 152. If the authors decide to maintain Figure 6, I recommend presenting it horizontally instead.
Point 13: I recommend specifying, in addition to the grain size distribution curve in Figure 7, the coefficients of uniformity and curvature.
Point 14: I recommend specifying the applied normal stresses (throughs weights) in Figure 8 from right to left.
Point 15: I recommend specifying, in addition to the captions of Figure 9–10, the photoinitiator content for easy referencing when reading the texts.
Point 16: In line 38, kindly check if it is "photo-curing geomembrane" or "photocured geomembrane"?
Point 17: In line 82, kindly change from Mirinae Kim [21] to Kim et al. [21], and remove "and others" in line 83.
Point 18: Check sentence construction from line 130 through line 132.
Point 19: In line 157 (Figure 5), kindly checked if the caption is "Photo-curing geomembran" or "Photocured geomembrane".
Point 20: Check sentence construction from line 161 through line 167. Be consistent in using the phrase "direct shear" instead of the phrase "straight shear" throughout the manuscript. Is the test sample pertaining to the soil specimen subject for testing or the photocured geomembrane after production (which will be trimmed down to match the shear box inner diameter)? Also, appropriately discuss the independence of clay properties from the sand properties.
Point 21: Check sentence construction from line 177 through line 179.
Point 22: In line 201, I recommend changing it to "Measured shear stress-displacement response".
Point 23: In line 265, consider removing the word "respectively".
Point 24: In line 268, kindly check if it is "continuous stress" or "continuous displacement".
Point 25: Be consistent in using the word "plowing" or "ploughing" throughout the manuscript.
Point 26: In line 405, kindly confirm if you are referring to Figures 13–14 and not Figure 10.
Point 27: Be consistent in using the term "geomembrane" throughout the manuscript. I noticed that the term "geosynthetic(s)" is interchangeably used in lines 391 and 407.
Major comments:
Point 28: In the first paragraph of the introduction, it seems to me that the motivation of the study is about the common failure occurring at the seams of geomembranes. However, further reading reveals that the current work focuses on the investigation of the interface characteristics between the geomembrane and soil and not on the seams. I recommend changing the "tone" of the first paragraph or avoiding putting emphasis on it.
Point 29: In the last paragraph of the introduction, it says that "In this paper, the interfacial shear properties of photo-cured geomembranes with different ratios of clay/sand were evaluated and analyzed, and ...". This statement is misleading as further reading reveals that there are no clay-sand ratios that were investigated in the study. I recommend reconstructing the phrase "photo-cured geomembranes with different ratios of clay/sand", which is constantly used throughout the manuscript, to explain the true intention of the study.
Point 30: Regarding lines 122–124, in what portion of the previous texts long-wave UV was mentioned? It seems to me that there was no previous discussion about the impact of long-wave UV on the curing reaction.
Point 31: The authors mentioned that the photoinitiator content ranges between 1%–5%. However, this seems to have a conflict with the statement from line 129 through line 130, which indicates that the photoinitiator content is generally no more than 3%. Are the authors referring to previous studies?
Point 32: Is the replacement of some amount of monomers, for photocured geomembrane production, by photoinitiator and carbon black powder in terms of weight or volume?
Point 33: In Section 4 (Direct shear tests), I recommend that the authors provide a schematic diagram of how the specimen (soil and geomembrane) was prepared in the shear box. This section strongly needs improvement. From line 192 through line 196, I recommend changing it to "A strain-controlled direct shear test was employed in the study with a rate of 0.8 mm/min. Normal stresses applied were 50 kPa, 100 kPa, 200 kPa, and 300 kPa (Figure 8, from right to left). The test is stopped when the shear displacement reaches 18 mm. The final peak shear stress is reported using the average value from 3 specimens tested per normal stress applied and specimen composition". Kindly check if the proposed revision has the same meaning as the original one.
Point 34: In Section 5.1, it seems that the observations are better to be explained by the dilative and contractive behaviors of soil rather than strain hardening and softening. If the authors decide to stick with these "strain hardening" and strain softening" terms rather than the proposed, I recommend adding the words "weak" and(or) "strong" to better describe the strain localization effect. The term "perfectly plastic" also best describes some of the shear stress-displacement response observed in Figures 9–10. A schematic diagram of the interplay between soil and geomembrane during shearing could also best explain visually the response of the system.
Point 35: In line 286, kindly check if you mean "strain hardening" and not "strain softening". This conflicts with the phrase used in line 359.
Point 36: I recommend including the Mohr-Coulomb failure envelope in Figures 11–12 for the control specimens (clay and sand without the geomembrane). This is mentioned in line 324 (for clay), however, the failure envelope is not included (Figure 11). This recommendation will also support the claim stated for sand (lines 351–352).
Point 37: Based on Figure 11, the generalization from line 324 through line 326 is not really evident as the increase in photoinitiator content does not guarantee an increase and decrease of friction angle and cohesion. Also, from line 326 through line 327, I find the statement contrasting with the statement from line 407 through line 411.
Point 38: Is the shear strength coefficient summarized in Table 4 similar to the friction coefficient, which is calculated using Eq. 1? Please be consistent with the terms used throughout the manuscript to avoid confusion.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper is well written. The study Investigates the interface shear characteristics between photo-curable geomembrane and soil. The technical content is less. The study can be supplemented by analytical/numerical studies.
The first part of the paper looks like a textbook as too generic things are stated.
The research gap and novelty of the study should be highlighted in the Introduction.
Author Response
Dear Editorial Department and Reviewing Experts: Hello, thank you for your valuable opinions on the article. In view of the questions raised, make the revision reply as follows, thank you!
Comments and Suggestions for Authors
The paper is well written. The study Investigates the interface shear characteristics between photo-curable geomembrane and soil. The technical content is less. The study can be supplemented by analytical/numerical studies.
A: By direct shear test reveals the geomembrane - clay/interface characteristics of sand, a number of previous papers have taken this approach, but in this paper, numerical analysis is not comprehensive, not real comprehensive response research process and mechanism, not conducive to the phenomenon of observation process, the numerical simulation in the process of simulation analysis, often to the boundary conditions and material properties, impact on the results of the analysis, and structure in the form of discretization. The results obtained are different from the precision, and have high randomness and low reliability. Based on this, and because numerical analysis is usually only used as an auxiliary means, the research purpose can be achieved through experiments. Therefore, only experimental means are used to achieve this goal.
The first part of the paper looks like a textbook as too generic things are stated.
A: Part of the introduction has been revised according to your requirement. It makes it more logical, it makes it less boring.
The research gap and novelty of the study should be highlighted in the Introduction.
A: I added a lot of this in the introduction, for example, "In the past, a lot of researchers have done a lot of research on geomembrane. The study of the interface between the geomembrane and clay/sand has always been an important direction in the field of geomembrane research, but the study of the interface between the photocured geomembrane and clay/sand is still a blank.
Reviewer 3 Report
good topic and in the scope of sustainability journal, however, few recommendations are available and authors have to improve the article.
Introduction, is good however, authors have to add the newest update research of up to 5 articles ( from 2020-2021), and must show the novelty of the paper after addressing the issue of research gap.
line 29: polyester: please add “polyethylene terephthalate (PET).”
line 41: “ to improve durability. “: please clarify and define durability and be specific of testing durability.
line 44: “ Therefore, ,,,,....... issue to civil engineering “ . Please re-write .
Ref. (8) to (21) , please arrange in table illustrating the major findings with the material and testing used.please add table.
please add standard testing methods for Table no.3.
Conclusions are good, however, still need to show the significance of results in term of stage of testing and the novelty.
Add recommendations for future work, please.
Ref. No. 16: please give details.
most references are not following the publication format.
Author Response
good topic and in the scope of sustainability journal, however, few recommendations are available and authors have to improve the article.
A: Dear Editorial Department and Reviewing Experts: Hello, thank you for your valuable opinions on the article. In view of the questions raised, make the revision reply as follows, thank you!
Introduction, is good however, authors have to add the newest update research of up to 5 articles ( from 2020-2021), and must show the novelty of the paper after addressing the issue of research gap.
A: The modification has been completed according to your requirements, and the modification results are put in the modified version.
line 29: polyester: please add “polyethylene terephthalate (PET).”
A: The original text has been revised as follows according to your require, as shown below:
Existing geomembranes are mainly made from polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC), which can be thermally and mechanically processed to form a continuous film [1].
line 41: “ to improve durability. “: please clarify and define durability and be specific of testing durability.
A: This geomembrane can be formed through the photo-curing chain reaction between acrylic monomer, and photoinitiator (reaction initiator), in which carbon black powder is added as an ultraviolet (UV) blocker to improve durability, durability is the ability of a material to resist the long-term damage of both itself and the natural environment. That is, the ability to ensure its durability. The better the durability, the longer the service life of the material.
line 44: “ Therefore, ,,,,....... issue to civil engineering “ . Please re-write .
A: Therefore, the study of photocured geomembrane has become a hot topic in the field of civil engineering.
Ref. (8) to (21) , please arrange in table illustrating the major findings with the material and testing used.please add table.
A: The modification has been completed according to your requirements, and the modification results are put in the modified version.
please add standard testing methods for Table no.3.
A: The physical parameters of the clay were obtained through geotechnical tests in the laboratory, It is shown in the revised version
Conclusions are good, however, still need to show the significance of results in term of stage of testing and the novelty
A: The geomembrane studied in this paper is mainly used in the composite bedding of garbage dump, which plays an important role in sustainable development. More importantly, photocurable geomembrane made from the right raw materials is environmentally friendly and not harmful to human health, in line with the magazine's focus on sustainable development.
The authors should stress the connection between these findings and the concept of sustainability to make it relevant. The article itself contains many errors, which should be fixed before the paper can be resubmitted.
Add recommendations for future work, please.
A: The modification has been completed according to your requirements, and the modification results are put in the modified version.
Ref. No. 16: please give details.
A: The modification has been completed according to your requirements, and the modification results are put in the modified version.
most references are not following the publication format
A: The modification has been completed according to your requirements, and the modification results are put in the modified version.
Reviewer 4 Report
In this work by Li et al., the authors prepared a photocurable geomembrane and characterized its properties. The theme of the paper is not aligned with the aims and scope of the journal, which deals with sustainability. The authors should stress the connection between these findings and the concept of sustainability to make it relevant. The article itself contains many errors, which should be fixed before the paper can be resubmitted.
1) The level of English and narration should be improved.
2) It is not true that the light-activated mechanism of polymerization is always like this. One could also expect radical cations or radical anions in some of the cases.
3) Overall, the contribution sounds like a technical paper without paying necessary attention to details or depth of the analysis.
4) Experimental section is full of omissions, which makes this paper irreproducible. For instance, it is not specified clearly what was the curing time. Instead, photos of beakers are provided. Please carefully screen this section to include all the key parts.
5) Formatting of the paper is inconsistent. The plots have different sizes, captions are separated from the corresponding sections/plots (e.g. Line 159), which makes this article poorly readable. The resolution of many plots is too low.
6) Most importantly, the study does not involve any analysis of statistics, so it is impossible to say if these results are statistically significant.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Minor comments:
Point 1: Kindly consider changing the title to ’Sand- and Clay-Photocured-Geomembrane Interface Shear Characteristics Using Direct Shear Test’.
Point 2: Again, kindly use an en dash (–) and not underscore (_) when indicating a range of numbers. For example, ‘The numbers range from 1–5’.
Point 3: Kindly decide if it is ‘photocured’ or ‘photo-cured’ throughout the manuscript. The two words seem to have the same meaning.
Point 4: In Table 2 of the revised manuscript and not from the authors’ responses to comments, kindly move the percentage sign (%) to the second line. Also, kindly consider changing the table caption to ’Clay properties’. Note that the properties listed are not physical properties. In Figure 4, kindly change ‘Particle size/mm’ to ‘Particle size (mm)’ and ‘Percent passing/mm’ to ‘Percent passing (%)’. In Figures 7–12, kindly all change ‘Shear displacement/mm’ to ‘Shear displacement (mm)’, ‘Shear stress/kPa’ to ‘Shear stress (kPa)’, ‘Normal stress/kPa’ to ‘Normal stress (kPa)’, and ‘Peak shear stress/kPa’ to ‘Peak shear stress (kPa)’.
Point 5: In line 114, kindly remove the whole statement. Also, note that Figure 2 does not describe the photocuring reaction process. Also, the third block in Figure 1, kindly change ‘Large area light curing geomembran’ to ‘Large area photo-curing geomembrane’. In Figure 3 (line 164), kindly change ‘Photocured geomembran’ to ‘Photocured geomembrane’. In Figure 5, kindly fix the arrows, precisely that of the last block at the bottom.
Point 6: Kindly check if this is better (lines 175 through 180). ‘The test utilized a ZJ-type strain-controlled direct shear apparatus, as shown in Figure 5. The test was carried out per the "Standard for Geotechnical Test Methods" (GBT 50123_2019) [32] and the "Technical Specifications for the Application of Geosynthetics" [33]. The test procedure for photocured geomembrane-clay is as follows. Before the test, the clay was dried, crushed, ground, and then passed through a set of sieves with the opening from 2 mm (top) to 0.425 mm (bottom), and the required water was added to reach the optimum moisture content and then allowed to stand for three days.’
Point 7: Kindly check if this is better (lines 166 through 171). ‘To investigate the effect of photocured geomembranes in practical engineering applications, a series of direct shear tests with different soil materials (sand and clay) and photocured geomembranes were carried out in this study. The photocured geomembrane has a diameter of 300mm and a thickness of 2mm. The sand used in this study is in near dry conditions with a water content of 0.79%. The sand density is 2.69 g/cm3. The coefficient of uniformity (Cu) is 5.2, and the curvature coefficient (Cc) is 1.2. The soil is well-graded sand per the Unified Soil Classification System (USCS). The particle size distribution is shown in Figure 4. On the one hand, the properties of the clay are listed in Table 3.’
Point 8: Again, kindly revise the last paragraph of the introduction.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
Revisions completed satisfactorily. In principle the paper may be accepted. Please ensure that the formatting is appropriate at the proof stage to make the article approachable.
Author Response
Thank you for your help and pointed out the problem, which greatly helped me to modify the article. This paper has standardized the corresponding format according to the requirements of the journal, so that the article will be closer to the requirements of the journal in the proof stage.María De La O Toscano-CruzMaría De La O Toscano-Cruz
