Geotechnical Characterization of Quito’s North-Central Zone as Applied to Deep Excavation in the Urban Setting

Round 1

Reviewer 1 Report

The title of article should be modified to the reasonable and logical sentence.

For the proper modelling of soil nailing structure, the more detailed information of interface elements should be provided in the numerical model using PLAXIS 2D FE program.

Author Response

First of all, the authors would like to thank the Reviewer for their contribution, thorough examination of the manuscript and valuable comments, which will undoubtedly enhance the manuscript’s quality. The authors have attempted to address each of the Reviewer’s comments and suggestions in this revised version of the manuscript. All comments made by the reviewer are addressed individually. In each case, the reviewer’s comment/question is presented first (in italics), after which the authors’ reply/answer is provided, and, finally, the action prompted by the reply is described.

In this version of the manuscript, the modified content is identified by highlighted text.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors are congratulated for the document 'Geotechnical Characterization of the North-Central Zone of the City of Quito, Ecuador. Application to a Deep Excavation in the Urban Setting', it has an interesting structure but does not contribute to the research, however, the only pertinent observations that I can comment on are:

The order proposed by the authors does not allow the document to be clear and generate research value, it is recommended that the authors use the Microsoft Word template Heritage MDPI structure for a more interesting research production such as: 1. Introduction: The introduction should briefly place the study in a broad context and highlight why it is important… 2 Materials and Methods: The Materials and Methods should be described with sufficient details to allow others to replicate and build on the published results… 3. Results: It should provide a concise and precise description of the experimental results, their interpretation, as well as the experimental conclusions that can be drawn… 4. Discussion: Authors should discuss the results and how they can be interpreted from the perspective of previous studies and of the working hypotheses… 5. Conclusions: This section is not mandatory but can be added to the manuscript if the discussion is unusually long or complex.

Dear authors, the methodological contribution is modest, it does not contemplate a systematic process, and the data from its qualitative inputs are not a significant contribution, the methodological part must be reviewed because it does not collaborate in the research.

Title:

'Geotechnical Characterization of the North-Central Zone of the City of Quito, Ecuador. Application to a Deep Excavation in the Urban Setting', the title is very long, it is recommended that it does not exceed 14-16 words and that it generates an attractive and interesting narration.

Abstract:

The Abstract it should be restructured and clearly emphasize the methodology and the advantages of the study highlighting its results and conclusions

Introduction

The introduction is superficial.

Line 40 It will be necessary to review this information "narrow streets" and "modern buildings" that is not appropriate with the characteristics of the study site, the road system is different and this area of the city by the construction period is characterized by another style of architecture.

Lines 46 – 54 It will be necessary for the authors to contextualize well the local geology and mineralogy of Quito, review the petrological and mineralogical data of the volcanic centres around Quito, which are several; there is no talk of Ruco Pichincha, Guagua Pichincha, Pululahua, Mojanda Fuya Fuya and even the Atacaso Ninahuilca to take Quito as a fill basin related to the inter-Andean valley and volcanic arc of regional geology, review texts by Daniel Andrade, Pablo Samaniego, Claude Robin, Silvana Hidalgo, etc.

It is true that there is no updated petrographic and petrological information, but the information that the authors state describes it superficially, so that it is not considered that "the Carolina" study area was a lagoon until the middle of the previous century, and that in the last decades of twentieth century, filling soils were identified in several of these areas.

Line 69 Based on which factor you took those three points; these extraction points were arbitrary or there is some logic for the designation of these sites.

Lines 92 – 99 Fill information that does not identify the same volcanic structure of the site, there are references out of context.

Lines 124 – 130 This information is general, as others have said; but it does not generate a scientific contribution of enhancement for the place of study.

Dear authors, avoid problems of writing and structure of the paragraphs, you repeat ideas frequently, this does not support a focused and fluid reading.

Materials and Methods:

3.1. In Situ Testing and Soil Samples

I can't find a logic that connects the three points of extraction of the sample, describe why?

There is very general information that has been said by others that is not described by the study site.

Methods

To find a greater scientific contribution help us to understand the method used in the research, it is understood the semi-quantitative data obtained by the samples in the laboratory, but how do you combine all the information?

Discussion

It will be necessary to clarify the relationship of the number of points analyzed and allow us to understand that they are a specific hypothesis of the soils "of the site", since there is filling in that entire area.

Highlight in the discussion section the benefit of the study, although it has a historical-geological and mineralogical reading too superficial.

Conclusions

Include this section, taking into account that you should focus on each of the findings of the methodology and the results obtained.

Avoid conclusions that are too general and not documented in the text.

References

Regarding the references. There is a lack of references from authors with wide experience in the local study.

Review current research and cite research groups that are constantly advancing on this topic.

Author Response

First of all, the authors would like to thank the Reviewer for their contribution, thorough examination of the manuscript and valuable comments, which will undoubtedly enhance the manuscript’s quality. The authors have attempted to address each of the Reviewer’s comments and suggestions in this revised version of the manuscript. All comments made by the reviewer are addressed individually. In each case, the reviewer’s comment/question is presented first (in italics), after which the authors’ reply/answer is provided, and, finally, the action prompted by the reply is described.

In this version of the manuscript, the modified content is identified by highlighted text.

Author Response File: Author Response.pdf

Reviewer 3 Report

In this manuscript, the index properties and mechanical parameters of the volcanic soil in the La Carolina financial district of Quito (Ecuador) were tested and analyzed by traditional test method. The results are useful in engineering practice. This manuscript is more like a technical report than a scientific paper. The following comment should be addressed.

1. There have been many studies on the volcanic soil. What are the innovations and highlights of this study?

2. The chemical component of the volcanic soil should be presented.

3. How many elements in the FE model? What is meaning of “A ‘very fine’ element mesh”? The convergence analysis of the FE model is necessary.

4. The K0 procedure and standard interfaces should be described.

5. “the Mohr Coulomb (MC) model presents very high soil uplift values at the bottom of the excavation, which is a situation that is not realistic”. Why this situation is not realistic?

6. The font of the symbols in the formula is not standard.

 

7. The clarity of Figure 12 needs to be improved.

Author Response

First of all, the authors would like to thank the Reviewer for their contribution, thorough examination of the manuscript and valuable comments, which will undoubtedly enhance the manuscript’s quality. The authors have attempted to address each of the Reviewer’s comments and suggestions in this revised version of the manuscript. All comments made by the reviewer are addressed individually. In each case, the reviewer’s comment/question is presented first (in italics), after which the authors’ reply/answer is provided, and, finally, the action prompted by the reply is described.

In this version of the manuscript, the modified content is identified by highlighted text.

Author Response File: Author Response.pdf

Reviewer 4 Report

The paper shows the geotechnical characterization of the La Carolina financial 11 district of Quito (Ecuador).

1) The paper is not a research paper but a case study / technical note. In fact, the results presented herein are based on simple and commonly used laboratory tests and in-situ tests.

2) The numerical study of the Soil Nailing system is not relevant and can be removed, as the main contribution is the geotechnical characterization. The authors conclude that two constitutive models are better than a third one in modeling the response of a soil nailing system. The reviewer agrees about the fact that HS-small is able to capture in a better way the soil response compared to MC (as in the case of a soil nailing system). Nevertheless, this result is not clearly supported by any evidence (experimental data) in this work. Moreover, most of these comments are things that have been known for a long time. Thus, there is not novelty and numerical analysis presented are not relevant in this contribution.

Author Response

First of all, the authors would like to thank the Reviewer for their contribution, thorough examination of the manuscript and valuable comments, which will undoubtedly enhance the manuscript’s quality. The authors have attempted to address each of the Reviewer’s comments and suggestions in this revised version of the manuscript. All comments made by the reviewer are addressed individually. In each case, the reviewer’s comment/question is presented first (in italics), after which the authors’ reply/answer is provided, and, finally, the action prompted by the reply is described.

In this version of the manuscript, the modified content is identified by highlighted text.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Dear authors of the document 'Geotechnical Characterization of Quito's North-Central Zone as Applied to Deep Excavation in the Urban Setting', the papers do not contribute investigative, it is insufficient; it is evident the lack of information of the site, methodology which represents results not suitable for a research journal high impact like Sustainability MDPI.

Author Response

The authors thank the reviewer for their time and assistance. We greatly appreciate your valuable feedback from the first and second review, as it helped us to create an investigative document of interest for the study area. Concurrently, we have taken the requirements of other reviewers into account, who have accepted the research topic and provided useful additional suggestions. To meet these requirements, we have added documentation to the introduction and geology sections. Specifically, we have augmented the information on the state-of-the-art research in the field of urban landslides, which aligns with the scope of this special issue of the journal. Concerning the geology of the study area, we have included essential, precise and context-specific information of the zone, as is customary in articles on geotechnical characterization published in high-impact journals, and cited some bibliographic references so that interested readers can further their research. We maintain that this study aims to focus directly on geotechnical characterization, determining parameters for the application of advanced soil constitutive models for the analysis of retaining structures, which are constantly used in the treatment of urban landslides, which is the main theme of the journal. 

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors took into account most of the comments, but some corrections still need to be made.

1. The number of the element in the FE model should be provided.

2. The convergence of the ‘very fine’ element mesh need to be verified.

Author Response

The authors thank the reviewer for their time and assistance. We greatly value your insightful comments from the first and second review, which have helped us to create an informative research document focused on the study area.

We are confident that this article is a case study that will have an impact on the progress of geotechnical engineering. It is a scientific article that examines volcanic soils in a region where volcanos are abundant, but which is lacking in studies focused on determining the physical and mechanical properties of volcanic soils with practical applications in geotechnical and civil engineering. The research is based on advanced laboratory tests that are not common in normal technical studies, thus allowing for the use of advanced soil constitutive models (Hardening Soil and HSsmall) for the study of Soil Nailing structures in volcanic soils. Furthermore, this topic is not abundant in indexed research. Ultimately, we believe that this study will significantly contribute to the development of geotechnical engineering, as it makes important contributions to the characterization of this type of soil and the analysis of structures for ground reinforcement in areas exposed to localized landslides, especially in urban environments.

The information included in this article represents the first part of our research. In this case, we have included the geotechnical characterization of the area and the analysis of a Soil Nailing structure that is regularly used in the treatment of urban landslides. Based on your recommendations and those of the other reviewers who have accepted the subject of this study, and with the aim of improving the presentation, we have added information to the introduction section to align this research more closely with the requirements of this special issue of the journal.

Author Response File: Author Response.pdf

Reviewer 4 Report

The authors addressed some of the concerns raised by the reviewer.

Author Response

The authors thank the reviewer for their time and assistance. We greatly value your insightful comments from the first and second review, which are aimed at obtaining an investigative document of interest for the study area. In parallel with responding to your observations, we have also addressed the requirements of other reviewers who have given their approval to the topic of this research and provided valuable additional suggestions. In accordance with these requirements, we have added documentation in the introduction and geology sections. Specifically, we have augmented the information on the state-of-the-art research in the field of urban landslides, which is precisely the scope of this special issue of the journal. With regards to the geology of the area, we have included basic and context-specific information of the zone, as is customary in articles on geotechnical characterization published in high-impact journals, and cited some bibliographic references so that interested readers can further their research. We believe that the main objective of this study is not to conduct a detailed geological analysis of the area, but rather to directly focus on the geotechnical characterization, determining parameters for the application of advanced soil constitutive models for the analysis of retaining structures, which are constantly used in the treatment of urban landslides, which is the main theme of the journal.

The information currently included in the article has been approved by the other reviewers, and it is already an extensive document with valuable information. The undertaking of a detailed geological study is a topic that we have planned for a future publication, and which will require a significant amount of space.

We are confident that this article is a case study that will have an impact on the progress of engineering. It is a scientific article that examines volcanic soils in a region where volcanos are abundant, but which is lacking in studies focused on determining the physical and mechanical properties of volcanic soils with practical applications in geotechnical and civil engineering. The research is based on advanced laboratory tests that are not common in normal technical studies, thus allowing for the use of advanced soil constitutive models for the study of Soil Nailing structures in volcanic soils. Furthermore, this topic is not abundant in indexed research. Ultimately, we believe that this study will significantly contribute to the development of geotechnical engineering, as it makes important contributions to the characterization of this type of soil and the analysis of structures for ground reinforcement in areas exposed to localized landslides, especially in urban environments.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Dear authors of the document 'Geotechnical Characterization of Quito's North-Central Zone as Applied to Deep Excavation in the Urban Setting', the papers do not contribute investigative, it is insufficient; it is evident the lack of information of the site, methodology which represents results not suitable for a research journal high impact like Sustainability MDPI.

Reviewer 3 Report

Accept