Research on the Design and Construction of Inclined Shafts for Long Mountain Tunnels: A Review

Round 1

Reviewer 1 Report

The review paper discussed the design and construction of incline shaft, which elaborated the deep insight for tunnel profile, lining structure, construction and operation ventilation, construction methods and machinery of the inclined shaft of long mountain tunnel.

The paper started with importance of incline shaft but missing vertical shaft discussion and why incline shaft is more preferable and economical as compare to vertical shaft.

Abstract line 17- have wrong spelling of mountain, “inclined shaft of long moutain tunnel”. Authors should check English. For example the first line of introduction paper “Following the construction of transportation infrastructure for long railways and trunk highways in western mountainous areas, tunnel construction in China has entered a rapid development period” Long sentence with flaw of words.

Next sentence also “The increasing number of super-buried and super-long tunnels is a prominent characteristic of tunnel engineering during this period”, don’t use super words, and use other appropriate words in place of these.

Authors should clears define “why the use or benefits of incline shaft in long mountain tunnels?” and why not parallel pilot pits? Also provide the linear sketches for both methods so that readers can understand easily.

Figure 3 and their analysis based on hypothesis, not scientifically and technically correct. Authors should avoid such hypothesis.

Authors should include more references related to tunnel operations which may be - Stability Analysis of Shallow Depth Tunnel in Weak Rock Mass: 3D Numerical Modeling Approach, Effect

of Underground Blasting on Surface Slope Stability: A Numerical Approach,

Authors should include some materials about tunnel stability analysis by geological points of view, laboratory and field investigations and computational modelling, for example- Finite Element Analysis of Road Cut Slopes using Hoek & Brown Failure Criterion; Analysis of rockfall hazards along NH-15: a case study of Al-Hada road; Digital rock physics and application of high-resolution micro-CT techniques for geomaterials; Correlation of ultrasound velocity with physico-mechanical properties of Jodhpur sandstone

As per my opinion, this review don’t have scientifically and technically strong, even no benefits to tunnel industry. All parameters taken by authors are generalize based on empirical or simple logic, not found any deep investigations by authors.

One positive thing is that authors collected all information for general tunnel operations in one place, so we may give chance after major revisions of MS.   

 

Need extensive work on English as mentioned in comments and suggestions sections of authors.

Author Response

1. One of the biggest advantages of the inclined shaft compared with the vertical shaft is that it can take into account the needs of auxiliary construction and operation ventilation. Some large machinery and equipment can enter the main tunnel construction through the inclined shaft excavated in advance, increase the working face of the main tunnel construction, and speed up the construction progress.
2. As a non-native speaker of English, there may be some inaccuracies in some expressions in this article. Thank you for your reminding, professor. In the next stage, I asked a senior brother who is good at English to help me modify and polish my words.

3.  For mountain tunnels, due to the large undulation of mountain terrain, the construction of a completely horizontal parallel pilot pits may not have good engineering conditions. At this time, the inclined shaft can be used to flexibly select the inlet and outlet positions and reduce the length of the auxiliary heading. As the professor said, provide the linear sketches for both methods so that readers can understand easily

   In the revised draft, I also modified Figure 3 and added relevant explanations to make it more scientific and easy to understand.

4. Dear Professor, you mentioned that let me add some tunnel stability analysis by geological points of view, laboratory and field investigations and computational modeling. I also took this into account when writing this article. In the original version of the manuscript, I made a statistical analysis of the structural stability calculation methods and support design methods commonly used in inclined shaft tunnels at present. I also went to several inclined shaft construction sites in Chongqing and Sichuan in China for investigation, but the conclusion was that compared with traditional mountain tunnels, The calculation method of surrounding rock pressure and support design method of inclined shaft tunnel and computational modeling have no obvious specificity. The existing calculation and design schemes mostly refer to the main tunnel, which is still in the stage of relying on experience summary and engineering analogy. Therefore, this section was finally deleted. The point mentioned by the professor is exactly the content that needs to be clarified in advance in the current design and construction process of inclined shaft, which needs to be further studied by the whole industry.

5. Finally, I would like to thank professor for reviewing my paper and giving me many useful suggestions in your busy schedule. I also adopted one of the sentences, "as per my opinion, this review don't have scientifically and technically strong, even no benefits to tunnel industry", which a little bit hurt my heart. but I will accept criticism with an open mind and work hard and make progress in my future writing.

Reviewer 2 Report

The article is well written and can be considered for publication. However, the following comments should be addressed to further improve the paper:

1. The title is misleading, especially the review aspect. If the paper is a review, then all the contents are not author's original work including tables and figures. More so, the formulae presented in the paper looks like that of the authors. If these are not the case, there is a need to include source of the tables, figures and formulae in the paper

2. There is a need to further justify the study especially regarding the selection of inclined shaft method. Are there other methods for construction tunnel? What makes the adopted method better?

3. What is the problem of the study and what is the issue with tunnel construction? Are there problems in literature on the use of inclined shaft method? Are there also suggestions for other methods?

4. The various methods, like envelope method, should be explained better in connection with the tunneling construction. This should be explained in line with the inclined shaft method, which is the focus of the paper.

5. The concluding section is okay except that it only include conclusion without explaining the limitation of the study, areas for further study and policy recommendations. The recommendations should be targeted at concerned stakeholders and the study should explain how the findings would benefit each of the stakeholders

 

The quality of English language is okay

Author Response

1. This article is mainly a summary of the development of inclined shafts of mountain tunnels in China at the present stage. The article is mainly based on the statistical analysis and summary of existing research papers, specifications, industry unified standards, existing projects, etc., which also contains a lot of my own relevant research and opinions, such as I collected all information for general tunnel operations in one place, etc, The source may not be marked well in the relevant quotation and description, which has been modified according to the professor's opinion.

2. There are many kinds of classification methods for the included shaft construction methods. I mainly explain them from the perspective of the construction sequence of the inclined shaft and the main tunnel, which can be divided into two types: the main shaft method when the inclined shaft is constructed first and then the main tunnel, and the reverse shaft method when the main tunnel is constructed first and then the inclined shaft. This classification focuses more on the functional analysis of the inclined shaft. Different construction sequences correspond to different functions of the inclined shaft. The main shaft method can assist the construction of the main tunnel, and the raise shaft rule is mainly used for ventilation.

3. In the design of inclined shaft support parameters and construction scheme, a key problem is to determine the surrounding rock pressure, but the existing calculation method of surrounding rock pressure is mainly for the main tunnel. At present, the design of inclined shaft support in China mainly refers to the main tunnel, which is still in the stage of relying on experience summary and engineering analogy. For example, in the 2004 edition of the code for design of highway tunnels, the lining and support parameters of inclined shafts with different surrounding rock levels are briefly specified. However, considering that the surrounding rock level, formation parameters, groundwater, in-situ stress, soil consolidation settlement and other factors all affect the surrounding rock pressure of inclined shaft lining, and the above factors interact to jointly affect the stability of inclined shaft surrounding rock, It is not scientific to simply stipulate the supporting measures according to the surrounding rock grade. Therefore, at present, the design and construction of inclined shaft mainly refer to the main tunnel, and the difference is mainly the influence of slope. It is necessary to pay attention to the anti slip car, construction safety and other factors.

4. Thank you for your comments, professor. I will further explain the variable construction methods and the limitation of the study in the revised version.

Reviewer 3 Report

This paper presents a research review on the design and construction of inclined shafts for long mountain tunnels. The results of the study were obtained by statistical analysis of data obtained from literature and actual cases and a comprehensive and systematic review conducted on the tunnel profile, lining structure, construction and operation ventilation, construction methods and machinery of the inclined shaft of long mountain tunnel. This paper only contains literature studies on the design and construction of inclined shafts for long mountain tunnels and is not the result of a study. This paper cannot be accepted in this journal because it does not contain the original research results of the authors and does not provide updates in related fields of knowledge. This paper is nothing more than a lecture note. Besides that, this paper has some typo errors, as seen in the title.

Author Response

This paper is a research review based on the research status of the existing mountain tunnel inclined shaft, which is based on the systematic review and Prospect of the existing research, and puts forward some suggestions. I don't agree with you about this paper is nothing more than a lecture note. If we can systematically summarize, elaborate and prospect the knowledge related to the design and construction of mountain tunnel inclined shaft, it's also very meaningful for people in this industry, It is also meaningful for scholars and engineers who want to systematically study the design and construction of inclined shafts. This is also the significance of review papers. Of course, I will humbly accept the relevant shortcomings mentioned by the professor and further improve them in the future.

Reviewer 4 Report

 

 

The article provides a comprehensive review of the design and construction specifications of inclined shafts in long mountain tunnels. The study utilizes literature statistics and actual case analysis to identify areas for improvement, including the gentle slope section design, ventilation management during operation, standardized supporting parameter design, and automation of transportation vehicles within the narrow inclined shaft space. The authors recommend further research on inclined shaft longitudinal slope design, construction and operation ventilation design, and transportation mode, particularly in relation to electric vehicle adoption. Overall, the study presents valuable insights for improving the efficiency and safety of inclined shafts in long mountain tunnels.

 

1.     Further explanation is needed on the design of the gentle slope section of the inclined shaft with a large longitudinal slope to clarify the improvements required.

 

2.     Provide more evidence or analysis supporting the suggestion to make full use of natural wind and how to eliminate its adverse effects in operation stage ventilation management.

 

3.     Discuss more on the standardized design of the supporting parameters, including the methodology and approach used to achieve this standardization.

 

4.     Elaborate on the practical demand for improving automation, intelligence, management, and dispatching level of transportation vehicles within the narrow inclined shaft space.

 

5.     Provide more in-depth analysis and evidence on the inevitable trend for electric vehicles to replace fuel vehicles, and the challenges and opportunities this presents for inclined shaft use in long mountain tunnels.

 

6.     Consider providing more details on the proposed research on inclined shaft longitudinal slope design, construction, and operation ventilation design and transportation mode.

 

7.     Address any potential limitations of the study, such as data sources or sample sizes, and suggest areas for further research or study.

 

Author Response

1. As professor mentioned, there is still a lack of research on the gentle slope section of inclined shaft at present, and the relevant construction rules and specifications have only shallow provisions. At this time, the inappropriate design of the gentle slope section may not play an effective role in blocking, so this is also the focus of our research group. At present, the invention patent has been published: a fully automatic flexible blocking device and its installation and layout algorithm for anti slip car in inclined shaft, This method can effectively cooperate with the setting of the gentle slope section, and can be applied to the emergency stop when the brake of the transport vehicle in the trackless transport inclined shaft fails. However, due to the copyright agreement, it cannot be mentioned in this article at present.
2. As mentioned in this article, I quantified the wind speed, wind pressures inside and outside the tunnel, and temperature at the protective door of the auxiliary tunnel in nine tunnels on a railway line. However, these data are measured in winter. In summer, the wind speed and pressure may be different due to the change of temperature and pressure. Therefore, we will go to the same tunnel and inclined shaft for measurement this summer. We hope to further explain how to make full use of natural wind to get the seasonal variation law of the whole year. In the conclusion of this article, I have also added relevant elaboration.
3. if it is only for the purpose of auxiliary ventilation, the inclined shaft section can be designed in narrow direction, but if it is for the purpose of auxiliary main tunnel construction, the narrow enclosed shaft space may not meet the transportation demand. At this time, in order to reduce the construction cost and speed up the construction progress, it is necessary to improve automation, intelligence, management, and dispatching level of transportation vehicles within the narrow enclosed shaft space.
4. According to the professor's suggestions, I explained the current peak carbon emission limit in China and the advantages of new energy vehicles over traditional oil vehicles in the revised draft, and explained the inevitable trend for electric vehicles to replace fuel vehicles and the challenges and opportunities this presentation for inline shaft use in long mountain tunnels

      5. According to the professor's suggestions, I further explained potential limitations of the study and provided more details on the proposed research in the revised draft. Finally, thank you for your comments and suggestions.

Round 2

Reviewer 1 Report

Now MS is in good shape after the tremendous efforts of the authors.

MS can be published as it is but need to again another look for english, i.e., line 17- still wrong spelling of mountain, written there "moutain"

please check it again.

Reviewer 3 Report

The authors have revised their paper as recommended by the reviewers.

Reviewer 4 Report

accept