Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load

Round 1

Reviewer 1 Report

In this paper, a study on fatigue damage evolution of the base plate structure of CRTS III slab ballastless track under heavy haul train load is performed, to explore the cracking phenomenon of the base plate concrete under fatigue load, a lab test and finite element simulation were carried out, and the experimental and numerical results are compared to explore the cracking phenomenon. The fatigue assessment in the base plate structure of CRTS III slab ballastless track under heavy haul train load is interesting, and the paper is relatively well organized and some useful conclusions are obtained. However, there are some important drawbacks and cannot be recommended to be accepted in the current form, major revision should be carried out, which can be listed as follows:

1. The literature review on the topics is relatively insufficient, more recent and relative studies are suggested to be included in the reference, especially those introduction and application of fatigue study in base plate, which have been applied successfully in the field of damage identification. The following references are suggested to be added in the section of Introduction.

• Vibration-based structural Damage Identification under Varying Temperature Effects[J]. Journal of Aerospace engineering, 2018, 31(3): 04018014.
• A hybrid ant lion optimizer with improved Nelder-Mead algorithm for structural damage detection by improving weighted trace lasso regularization[J]. ADVANCES IN STRUCTURAL ENGINEERING, 2020, 23 (3) , pp.468-484
• Structural Damage Identification Based on l(1)Regularization and Bare Bones Particle Swarm Optimization with Double Jump Strategy[J]. MATHEMATICAL PROBLEMS IN ENGINEERING, 2019, 5954104
• Structural damage detection via combining weighted strategy with trace Lasso[J]. ADVANCES IN STRUCTURAL ENGINEERING, 2019, 22 (3), pp.597-612
• Temperature Effects on Vibration-Based Damage Detection of a Reinforced Concrete Slab, APPLIED SCIENCES-BASEL,2020, 10(8)
• Identification of moving vehicle forces on bridge structures via moving average Tikhonov regularization[J]. SMART MATERIALS AND STRUCTURES, 2016, 26(8)
• Damage Identification of a Steel Frame Based on Integration of Time Series and Neural Network under Varying Temperatures[J]. ADVANCES IN CIVIL ENGINEERING, 2020
• Structural damage detection via adaptive dictionary learning and sparse representation of measured acceleration responses[J]. MEASUREMENT, 1018, 128, pp.377-387

   

2. There are too much references in Chinese, which is not helpful for the readers to understand the contents of the paper.

3. In the paper, there are many grammar errors and typos, extensive editing of English language and style required, eg. Line 59, 63 and too much misuse of ‘the’.

4. The section of Introduction should be rewritten.

5. What is the meaning of ‘the lateral and lateral strain ….’ In line 265 and 287, should the latter one be ‘longitudinal’.

6. The paper is too long, there are too many figures and tables, some similar figures can be made merged, for examples, in the comparison of the three working conditions (Should be Cases).

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022

Dear Reviewer:

Thank you very much for your attention and the reviewers’ evaluation and comments on our paper “Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load”. We have revised the manuscript according to your kind advice. The review comments are in italics, and my answers are in italics.

We sincerely hope this manuscript will be finally acceptable to be published on Applied Sciences. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards

Yours sincerely,

Zhiping Zeng

Please find the following Response:

A point-by-point reply to Reviewer #1

Reviewer: 1

1. The literature review on the topics is relatively insufficient, more recent and relative studies are suggested to be included in the reference, especially those introduction and application of fatigue study in base plate, which have been applied successfully in the field of damage identification. The following references are suggested to be added in the section of Introduction.

• Min-Shui Huang, Mustafa Gül, A.M.ASCE, Hong-Ping Zhu. Vibration-based structural Damage Identification under Varying Temperature Effects. Journal of Aerospace engineering, 2018, 31(3): 04018014.
• Chengbin Chen, Ling Yu. A hybrid ant lion optimizer with improved Nelder-Mead algorithm for structural damage detection by improving weighted trace lasso regularization. ADVANCES IN STRUCTURAL ENGINEERING, 2020, 23 (3) , pp.468-484
• Minshui Huang, Yongzhi Lei, Xifan Li. Structural Damage Identification Based on l(1)Regularization and Bare Bones Particle Swarm Optimization with Double Jump Strategy. MATHEMATICAL PROBLEMS IN ENGINEERING, 2019, 5954104
• Chengbin Chen, Chudong Pan, Zepeng Chen, Ling Yu. Structural damage detection via combining weighted strategy with trace Lasso. ADVANCES IN STRUCTURAL ENGINEERING, 2019, 22 (3), pp.597-612
• Zhenpeng Wang, Minshui Huang, Jianfeng Gu. Temperature Effects on Vibration-Based Damage Detection of a Reinforced Concrete Slab, APPLIED SCIENCES-BASEL,2020, 10(8)
• Chu-Dong Pan, Ling Yu, Huan-Lin Liu. Identification of moving vehicle forces on bridge structures via moving average Tikhonov regularization. SMART MATERIALS AND STRUCTURES, 2016, 26(8)
• Minshui Huang, Wei Zhao, Jianfeng Gu,Yongzhi Lei. Damage Identification of a Steel Frame Based on Integration of Time Series and Neural Network under Varying Temperatures. ADVANCES IN CIVIL ENGINEERING, 2020
• Zepeng Chen, Chudong Pan, Ling Yu. Structural damage detection via adaptive dictionary learning and sparse representation of measured acceleration responses. MEASUREMENT, 2018, 128, pp.377-387

The related literature review on this topic has been supplemented. More recent and relative fatigue studies in base plate, like the above 8 articles, have been added in the references, and the contents of these studies have also been added to the end of section 1.1.2, as follows:

However, for heavy-haul railway, the track structure is prone to fatigue damage due to the long-term impact of large train load and external temperature and humidity environment. In recent years, many researches on structural damage detection methods and detection principles have sprung up.

In [13], Min-Shui Huang, based on genetic algorithm, proposed a vibration-based damage identification method, which is used to identify the location and severity of structural damage under the influence of temperature change and noise; A new damage identification optimization algorithm is proposed in [14], it is called bare bones particle swarm optimization with double jump (BBPSODJ), which has good adaptability; In [15], a method combining autoregressive (AR) time series model and two-step artificial neural networks (ANNs) is proposed to identify damage under temperature change. In [16], Chengbin Chen proposed a hybrid algorithm for damage detection of complex structures, that is, the ant colony optimization algorithm is combined with the improved Nelder Mead algorithm. In [17], Chengbin Chen combined the weighting strategy with the track-ing minimum absolute contraction and selection operator (lasso) to form a new structural damage detection method. Zhenpeng Wang [18] obtained the functional relationship be-tween temperature and frequency through experiments, established the model between them, and identified the structural damage under the influence of temperature according to the particle swarm optimization (PSO) algorithm. Chu-Dong Pan [19] proposed a new moving average Tikhonov regularization method, which can accurately identify the mo-tion force and can be used for structural damage prevention and control. Zepeng Chen [20] proposed a new damage index (CMS) to obtain a sparse representation of the acceleration response for damage identification, so as to extract damage sensitive features from the measured acceleration response.

At present, these structural damage detection methods have been widely used in civil engineering, but their application in structural damage identification of CRTS III ballast-less track on heavy-haul railway is relatively limited. In order to promote the application of structural damage detection methods in this regard, so as to prevent, reduce and timely control structural fatigue damage, it is necessary to study the fatigue damage performance of CRTS III ballastless track structure on heavy-haul railway, which has important engi-neering value.

 

2. There are too much references in Chinese, which is not helpful for the readers to understand the contents of the paper.

Some other international papers have been appropriately added, and some Chinese literatures have been deleted, at the same time, relevant research contents have also been added to the end of section 1.1.3, as follows:

Yu Zhiwu [33] conducted indoor test on CRTS III slab ballastless track structure, es-tablished the corresponding simulation calculation model based on ANSYS, analyzed the mechanical characteristics of CRTS III slab ballastless track structure, and obtained the damage evolution law of CRTs III slab ballastless track structure under high-speed train load. Zeng Zhi-ping [34] carried an experimental study on the full-scale model of CRTS III slab track structure, applied 30 million cyclic loads to the structure, and analyzed the evolutions of dynamic and static stiffness and acceleration of each layer structure after fa-tigue load. Xu Qingyuan [35] established the spatial dynamic model of vehicle CRTS III slab track subgrade, and studied the influence of the vehicle number on the characteristics of vehicle-track-subgrade system. Based on the self-developed preloading device, Kunlin Ma [36] studied the performance evolution and damage of self-compacting concrete under the combined action of load and freeze-thaw cycle .

• Yu Zhiwu, Xie Ying, Shan Zhi, and Li Xiao, Fatigue Performance of CRTS III Slab Ballastless Track Structure under High-speed Train Load Based on Concrete Fatigue Damage Constitutive Law. Journal of Advanced Concrete Technology, 2018, 16(5):223-249.
• Zeng Zhi-ping,Wang Jun-dong,Shen Shi-wen,Li Ping,Abdulmumin Ahmed Shuaibu,Wang Wei-dong. Experimental Study on Evolution of Mechanical Properties of CRTS III Ballastless Slab Track under Fatigue Load. Construction and Building Materials,2019,210: 639-649
• Xu Qingyuan, Sun Hao, Wang Lexuan, et al. Influence of Vehicle Number on the Dynamic Characteristics of High-Speed Train-CRTS III Slab Track-Subgrade Coupled System, Materials,2021, 14(13): 3662-3662.]
• Kunlin Ma,Shuangjie Li,Guangcheng Long,Youjun Xie,Lianshan Yu,Qingquan Xie. Performance Evolution and Damage Constitutive Model of Thin Layer SCC under the Coupling Effect of Freeze–Thaw Cycles and Load[J]. Journal of Materials in Civil Engineering,2020,32(6).

 

And:

Zeng established the finite element model of heavy-haul train and obtained the mechanical characteristics of track structure under different load conditions [28]. Zeng also established the CRTSI ballastless track structure by using the finite element method, and studied the displacement and acceleration of the structure under different working conditions [29].

[28]Zeng Zhiping,Hu Guanghui,Huang Xiangdong,Wang Weidong,Qahtan Ayoub Abdullah Senan,Shuaibu Abdulmumin Ahmed,Wang Jundong. Statics performance of heavy-haul railway low-vibration track (LVT) under varying loading condition with the finite element method.[J]. Science progress,2021,104(4):

[29]Zeng Zhiping,Ye Mengxuan,Liu Fushan,Shuaibu Abdulmumin Ahmed,Wang Weidong,Meng Xiaobai. Dynamic response of CRTS I double-block ballastless track under three-dimensional temperature and falling-shaft impact loadings[J]. Advances in Mechanical Engineering,2021,13(3):

 

3. In the paper, there are many grammar errors and typos, extensive editing of English language and style required, eg. Line 59, 63 and too much misuse of ‘the’.

In line 59, the redundant word “are” has been deleted. In line 63，“have” has been replaced with “has”. The redundant words “the” have been deleted.

 

4. The section of Introduction should be rewritten.

According to your suggestions, the introduction has been rewritten, and two subheadings have been used to distinguish the research background from the research content

 

5. What is the meaning of ‘the lateral and lateral strain ….’ In line 265 and 287, should the latter one be ‘longitudinal’.

Yes, the latter one should be ‘longitudinal’, and now the latter “lateral” has been replaced with ‘longitudinal’.

 

6. The paper is too long, there are too many figures and tables, some similar figures can be made merged, for examples, in the comparison of the three working conditions (Should be Cases).

Some pictures in the text have been merged.

Author Response File: Author Response.docx

Reviewer 2 Report

Most of the results presented in this paper have been already published by the same authors in the following paper:

Research on the fatigue performance of self-compacting concrete structure in CRTSIII slab ballastless track under the action of heavy haul train

If it is otherwise, you can delete the repeated figures and just reference to the previous journal paper so the reviewer can realize the novelty of the new study. With the current format, I have to reject the manuscript. 

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022

Dear Reviewer:

Thank you very much for your attention and the reviewers’ evaluation and comments on our paper “Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load”. We have revised the manuscript according to your kind advice. The review comments are in italics, and my answers are in italics.

We sincerely hope this manuscript will be finally acceptable to be published on Applied Sciences. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards

Yours sincerely,

Zhiping Zeng

Please find the following Response:

A point-by-point reply to Reviewer #2

Reviewer: 2

Most of the results presented in this paper have been already published by the same authors in the following paper:

Research on the fatigue performance of self-compacting concrete structure in CRTSIII slab ballastless track under the action of heavy haul train

If it is otherwise, you can delete the repeated figures and just reference to the previous journal paper so the reviewer can realize the novelty of the new study. With the current format, I have to reject the manuscript. 

Thank you for your review and criticism. I have deleted or quoted the repeated contents in the article. Since the experimental devices used in the two papers are the same, and only one experimental device diagram (Fig. 6) was reserved when doing the experiment, in order to make the readers better understand the experiment, the experimental device diagram is retained, and reference 39 is marked in the text.

The research content and object of this paper are different from that of the paper“Research on the fatigue performance of self-compacting concrete structure in CRTSIII slab ballastless track under the action of heavy haul train”. The research methods of the two papers are similar, but the research objects and results are different. One is mainly for self -compacting concrete and the other is mainly for base plate. Therefore, there is no repetition in the content, that is to say, the same model is used for different calculations. Therefore, the model diagrams used in figure 7 (b), figure 8, figure 10 and figure 13 are the same as those in this paper. Therefore, these pictures are referenced here.

Author Response File: Author Response.docx

Reviewer 3 Report

Please correct some typos, for example

• row 113, start of sentence...
• row 265, ...the lateral and lateral strain ???
• row 287, the same sentence as in row 265, row 290, etc.
• row 348, describe the FEM solver (ANSYS ?) and the types of elements
• how is the subsoil modeled? , see Table 1
• row 384, capital letter...
• Fig. 14 are too small
• row 525, two commas ...
• row 541, doy you mean working conditions as a type of loading conditions ?

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022

Dear Reviewer:

Thank you very much for your attention and the reviewers’ evaluation and comments on our paper “Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load”. We have revised the manuscript according to your kind advice. The review comments are in italics, and my answers are in italics.

We sincerely hope this manuscript will be finally acceptable to be published on Applied Sciences. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards

Yours sincerely,

Zhiping Zeng

Please find the following Response:

A point-by-point reply to Reviewer #3

Reviewer: 3

Please correct some typos, for example

1. row 113, start of sentence...

In row 113, “during” has been replace with “During”.

 

2. row 265, ...the lateral and lateral strain ???

The latter “lateral” should be ‘longitudinal’, and now has been replaced with ‘longitudinal’.

 

3. row 287, the same sentence as in row 265, row 290, etc.

The latter “lateral” should be ‘longitudinal’, and now has been replaced with ‘longitudinal’.

 

4. row 348, describe the FEM solver (ANSYS ?) and the types of elements

how is the subsoil modeled? see Table 1

(1) ANSYS software is a large general finite element analysis (FEA) software developed by American ANSYS company. It is the fastest growing computer-aided engineering in the world (CAE) software. The software mainly includes three parts: pre-processing module, analysis and calculation module and post-processing module. The pre-processing module provides a powerful solid modeling and meshing tool, and users can easily construct finite element models; the analysis and calculation module includes structural analysis (it can carry out linear analysis, nonlinear analysis and highly nonlinear analysis), hydrodynamic analysis, electromagnetic field analysis, sound field analysis, piezoelectric analysis and coupling analysis of multiple physical fields. It can simulate the interaction of multiple physical media and has the ability of sensitivity analysis and optimization analysis. The analysis type used in this study is structural analysis; the post-processing module can integrate the calculation results It can be displayed in the form of color contour display, gradient display, vector display, particle flow trace display, three-dimensional slice display, transparent and translucent display (the interior of the structure can be seen), and the calculation results can also be displayed or output in the form of charts and curves. Since the introduction of software is not the focus of this paper, it is only described here.

(2) Beam188 element was selected to simulate steel rail. Solid65 element was selected to simulate the concrete structure of track slab, self-compacting concrete layer and base plate, while combin14 element was selected to simulate foundation. The track slab was consolidated with the self-compacting concrete layer, and the contact between the self-compacting concrete and the base plate was simulated by target170 element. The specific element selection is shown in Table 3.

(3) By referring to the methods and numerical values described in [38], the parts below the base plate are simulated by combin14 element. That is to say, the combin14 element includes the simulation of subsoil.

5. row 384, capital letter...

In row 384, “thus” has been replaced with “Thus”.

6. Fig. 14 are too small

Fig. 14 has been enlarged.

7. row 525, two commas ...

In row 525, a comma has been deleted.

8. row 541, doy you mean working conditions as a type of loading conditions ?

Yes, we regard each loading condition as a working condition.

Author Response File: Author Response.docx

Reviewer 4 Report

The topic of the manuscript is interesting and may be the subject of research, however, the manuscript organization, state of the art, and discussion are not appropriate in the scientific journal. Therefore I recommend strongly improving the manuscript taking into account the following remarks and comments: 

1. Title and keywords: Please do not use abbreviations, especially those which are not commonly used in the literature.

2. Introduction should be strongly revised taking into account the international achievements in the scope of slab ballastless tracks. Based on this review, the authors should present CRTS III and underline what is a new approach. Some benefits of using this type of slab should also be given. 

3. Section 2.1: Firstly, The authors referenced [31-32] but these works are written in Chinese and can not be verified. 
Secondly, how many fatigue load cycles have been used in the laboratory tests? What were the values of load used? 

4. Fig. 14: Load schemes presented in Fig. 14 are different than in Fig. 10. Please verify and give comments. 

5. Lines 443-450 and so on, Figs. 15-17: Please comment on such big errors between measured and theoretical values. 

6. Discussion: It is necessary to refer the obtained results to other results of the structural solutions of the ballastless track and appropriate international standards.

7. References: Please do not use Chinese literature because they are not possible to read by the international community. The authors used 21 Chinese references. This is not appropriate in scientific journals. 
Besides, References [1] and [2] are the same. 

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022

Dear Reviewer:

Thank you very much for your attention and the reviewers’ evaluation and comments on our paper “Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load”. We have revised the manuscript according to your kind advice. The review comments are in italics, and my answers are in italics.

We sincerely hope this manuscript will be finally acceptable to be published on Applied Sciences. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards

Yours sincerely,

Zhiping Zeng

Please find the following Response:

A point-by-point reply to Reviewer #4

Reviewer: 4

The topic of the manuscript is interesting and may be the subject of research, however, the manuscript organization, state of the art, and discussion are not appropriate in the scientific journal. Therefor I recommend strongly improving the manuscript taking into account the following remarks and comments: 

1. Title and keywords: Please do not use abbreviations, especially those which are not commonly used in the literature.

These abbreviations in title and keywords have been replaced with their full name.

 

2. Introduction should be strongly revised taking into account the international achievements in the scope of slab ballastless tracks. Based on this review, the authors should present CRTS III and underline what is a new approach. Some benefits of using this type of slab should also be given. 

(1) International Researches on CRTS III slab ballastless tracks have been added to the introduction. And in order to facilitate readers' understanding, corresponding literature has been added to the references, as follows:

Yu Zhiwu [33] conducted indoor test on CRTS III slab ballastless track structure, es-tablished the corresponding simulation calculation model based on ANSYS, analyzed the mechanical characteristics of CRTS III slab ballastless track structure, and obtained the damage evolution law of CRTs III slab ballastless track structure under high-speed train load. Zeng Zhi-ping [34] carried an experimental study on the full-scale model of CRTS III slab track structure, applied 30 million cyclic loads to the structure, and analyzed the evolutions of dynamic and static stiffness and acceleration of each layer structure after fa-tigue load. Xu Qingyuan [35] established the spatial dynamic model of vehicle CRTS III slab track subgrade, and studied the influence of the vehicle number on the characteristics of vehicle-track-subgrade system. Based on the self-developed preloading device, Kunlin Ma [36] studied the performance evolution and damage of self-compacting concrete under the combined action of load and freeze-thaw cycle.

• Yu Zhiwu, Xie Ying, Shan Zhi, and Li Xiao, Fatigue Performance of CRTS III Slab Ballastless Track Structure under High-speed Train Load Based on Concrete Fatigue Damage Constitutive Law. Journal of Advanced Concrete Technology, 2018, 16(5):223-249.
• Zeng Zhi-ping,Wang Jun-dong,Shen Shi-wen,Li Ping,Abdulmumin Ahmed Shuaibu,Wang Wei-dong. Experimental Study on Evolution of Mechanical Properties of CRTS III Ballastless Slab Track under Fatigue Load. Construction and Building Materials,2019,210: 639-649
• Xu Qingyuan, Sun Hao, Wang Lexuan, et al. Influence of Vehicle Number on the Dynamic Characteristics of High-Speed Train-CRTS III Slab Track-Subgrade Coupled System, Materials,2021, 14(13): 3662-3662.]
• Kunlin Ma,Shuangjie Li,Guangcheng Long,Youjun Xie,Lianshan Yu,Qingquan Xie. Performance Evolution and Damage Constitutive Model of Thin Layer SCC under the Coupling Effect of Freeze–Thaw Cycles and Load[J]. Journal of Materials in Civil Engineering,2020,32(6).

(2) At the same time, the novelty of this study is supplemented in section 1.2.1, as follows:

A large number of tests and theoretical studies have been done at home and abroad on the mechanical properties of heavy-haul railway, CRTS III slab ballastless track and ballastless track of heavy haul railway. However, looking at these research results, there are few reports on the theoretical and experimental studies on the structural mechanical properties of CRTS III slab ballastless track under the action of heavy-haul train, especially for the base plate structure.

(3) Some benefits of using this type of slab are described in section 1.2.1, as follows:

CRTS III slab has structural stability and good integrity, and it has no obvious weakness. It also has the characteristics of simple structure, high manufacturing accuracy, less surface cracks or no cracks, and small fine adjustment workload. Therefore, this kind of slab is widely used in railways.

 

3. Section 2.1: Firstly, The authors referenced [31-32] but these works are written in Chinese and can not be verified. Secondly, how many fatigue load cycles have been used in the laboratory tests? What were the values of load used? 

(1) In order to increase readability and applicability, English literature is added here, as follows:

[41]      Zhu, KT (Zhu, Kunteng)，Zeng, ZP (Zeng, Zhiping)，Wu, B (Wu, Bin)，Wei, W (Wei, Wei). (2016). Mechanical Property Verification of CRTS Ill Slab Track under Train Load,In: 6th International Conference on Electronic, Mechanical, Information and Management Society (EMIM), Shenyang, PEOPLES R CHINA,APR 01-03, 2016,pp,1464-1469, ACSR-Advances in Computer Science Research

• In this test, the simplified calculation method is used to obtain the simulated dynamic load. According to the development trend of heavy haul railway, the maximum axle load is calculated as 30t, the vertical fatigue live load is taken as 1.5 times of the static wheel load, the upper limit value of design fatigue load is taken as 90t, and the lower limit value of fatigue load is taken as 9t, according to the rule that lower limit value / upper limit value = 0.1.^[48] The static loading test shall be carried out in stages of 50kN, 100kN and until to 900kN.

(2) The total number of fatigue loads is 8 million times.

 

4. Fig. 14: Load schemes presented in Fig. 14 are different than in Fig. 10. Please verify and give comments. 

As described in section 2.3.1, the load scheme in Figure 14 is that a two-axle four-wheel loading is acted on the steel rail. As shown in Figure 10, while conducting the indoor test, the two cross beams and one longitudinal beam installed on the steel rail are similar to the vehicle bogie, and the four contact points between the cross beam and the steel rail are equivalent to four wheels, therefore, the essence is that a two-axle four-wheel loading is acted on the rail. So the two loading schemes are the same, and the use of this loading method in the test is conducive to controlling the consistency of the four wheel loads.

 

5. Lines 443-450 and so on, Figs. 15-17: Please comment on such big errors between measured and theoretical values. 

The causes of errors are as follows:

1. In terms of test

During static and cyclic loading tests, accidental errors may also occur due to human factors and environmental factors. For example, the position of loading point cannot be completely accurate, the installation position of each cross beam and longitudinal beam may also have slight deviation, and the loading rate is difficult to fully grasp.

2. In terms of simulation

During the simulation calculation, some reasonable assumptions are made for the model. For example, it is considered that the calculation model is ideally continuous and has no holes, that is, the displacement has single value, but it is difficult to avoid the introduction of initial hole defects in the actual construction. It is considered that the material parameters of the model do not change with space and are uniform, but the material of the actual track structure model is not uniform. In addition, although the material parameters used in the model are taken according to the specifications and previous literature, these material parameters can not fully reflect the material heterogeneity caused by the process.

Therefore, there are some errors between the theoretical calculation value and the experimental value, but it can be seen from these figures that the errors are not too large, and the variation law of the real value is consistent with that of the calculated value. Referring to previous studies, it can be seen that the model has sufficient reliability.

 

6. Discussion: It is necessary to refer the obtained results to other results of the structural solutions of the ballastless track and appropriate international standards.

Due to the lack of relevant international standards for the stress and displacement of CRTSIII slab track structure, only the previous literature is cited in the discussion part of this paper. According to the previous research results, the research conclusions of this paper are reliable and can provide a theoretical basis for engineering design and construction.

Combined with the suggestion of another reviewer, the discussion needs to be simplified, only the research literature available for reference is listed in the discussion part, so that interested readers can have an in-depth understanding. The specific contents of the literature listed here is different from that of this paper, but the research conclusions are similar, and they are all studied for CRTS III slab ballastless track structure of heavy haul railway, which can be verified by each other.

The discussion:

From the results performed in this study, the following phenomena can be found:

The acceleration of the base is lower than that of the track slab in the early stages of the train load by half. The isolation layer can effectively reduce the downward transmis-sion of vibration from the upper part of the track structure. However, the increase in the ri-gidity of the fastener and the isolation layer has an adverse effect on the stress of the structural system, especially the stress on the base.

Through the comparative analysis of the displacement and stress of the track struc-ture under the static force and the fatigue load, the established fatigue finite element nu-merical model can effectively reflect the mechanical performance of the base plate of the CRTS III slab ballastless track structure under the action of a heavy-haul train.

As the number of fatigue loads increases, the stress of the structural layer gradually increases. Under the action of fatigue load, the damage of the base concrete gradually in-creases, while the residual strength gradually decreases. An increase in the number of cy-cles of fatigue load to certain limit the longitudinal tensile stress of the concrete at the mid-span portion of the bottom surface of the base equates its tensile strength, thus, the stress degrades to zero, which implies, concrete cracks occurrence. With the further in-crease of the number of fatigue loads, the cracks of the base plate propagates from the edge of the plate to the center of the plate.

For the tensile stress of the base under the three working conditions, the longitudinal tensile stress is always greater than the lateral tensile stress, which implies it plays an important role in the fatigue damage process of the structure. Hence, it is critical to pay at-tention to the simplified calculation of the longitudinal stress in the structural design. When the load acts on the slab-end sleeper, both the longitudinal and lateral stresses of the base reached their maximum, thereby implying that the base at the end of the slab is the weak zone. Thus, when the train passes through the end of the slab track structure, an unfavorable condition arises as a result of increased force that results in increased stress.on the track structure. For the overall design of the CRTS III slab ballastless track, it is necessary to strengthen the design of the structural layer at the end of the slab.

Hve been replaced with:

From the results performed in this study, the following phenomena can be found:

(1) The acceleration of the base is lower than that of the track slab in the early stages of the train load by half. The isolation layer can effectively reduce the downward transmis-sion of vibration from the upper part of the track structure. However, the increase in the ri-gidity of the fastener and the isolation layer has an adverse effect on the stress of the structural system, especially the stress on the base.

(2) By comparing the displacement and stress under static load and fatigue load, the errors under the two conditions are acceptable and the variation law of the real value is consistent with that of the calculated value, which are similar to those in [41]. Therefore, it can be concluded that the fatigue-loaded finite element model could effectively describe the mechanical behavior of the base plate of CRTS III slab ballastless track structure under heavy haul train force.

(3) As the number of fatigue loads increases, the stress of the structural layer gradually increases, the base concrete gradually damages, and the residual strength gradually decreases. Until the longitudinal tensile stress of the concrete at the mid-span portion at the bottom of the base is equal to its tensile strength, the concrete cracks appear, and then the bottom plate cracks gradually expand from the edge to the center of the plate.

(4) For the tensile stress of the base under the three working conditions, the longitudinal tension stress is always greater than the lateral. Hence, it is critical to attach im-portance to the simplified analysis of the longitudinal stress in the structural design. When the load acts on the slab-end sleeper, both the longitudinal and lateral stresses of the base reached their maximum, implying the base at the end of slab is the weak zone. Thus, for the overall design of CRTS III slab ballastless track, it is necessary to strengthen the design of the structural layer at the end of the slab.

 

7. References: Please do not use Chinese literature because they are not possible to read by the international community. The authors used 21 Chinese references. This is not appropriate in scientific journals. Besides, References [1] and [2] are the same. 

According to your suggestion, reference 1 has been deleted and some international researches on CRTS III slab track have been supplemented in the article, which are listed below. However, since this type of slab is a track slab independently developed by China, China has done sufficient research in this field. And the key industry reports and specifications cited in this paper are very helpful for the in-depth understanding of the research. In order to facilitate scholars from all countries to have a deeper understanding, while supplementing the international literatures just parts of the Chinese literatures listed in the article are deleted. The supplemented literatures are:

• Min-Shui Huang, Mustafa Gül, A.M.ASCE, Hong-Ping Zhu. Vibration-based structural Damage Identification under Varying Temperature Effects. Journal of Aerospace engineering, 2018, 31(3): 04018014.
• Minshui Huang, Yongzhi Lei, Xifan Li. Structural Damage Identification Based on l(1)Regularization and Bare Bones Particle Swarm Optimization with Double Jump Strategy. MATHEMATICAL PROBLEMS IN ENGINEERING, 2019, 5954104
• Minshui Huang, Wei Zhao, Jianfeng Gu,Yongzhi Lei. Damage Identification of a Steel Frame Based on Integration of Time Series and Neural Network under Varying Temperatures. ADVANCES IN CIVIL ENGINEERING, 2020
• Chengbin Chen, Ling Yu. A hybrid ant lion optimizer with improved Nelder-Mead algorithm for structural damage detection by improving weighted trace lasso regularization. ADVANCES IN STRUCTURAL ENGINEERING, 2020, 23 (3) , pp.468-484
• Chengbin Chen, Chudong Pan, Zepeng Chen, Ling Yu. Structural damage detection via combining weighted strategy with trace Lasso. ADVANCES IN STRUCTURAL ENGINEERING, 2019, 22 (3), pp.597-612
• Zhenpeng Wang, Minshui Huang, Jianfeng Gu. Temperature Effects on Vibration-Based Damage Detection of a Reinforced Concrete Slab, APPLIED SCIENCES-BASEL,2020, 10(8)
• Chu-Dong Pan, Ling Yu, Huan-Lin Liu. Identification of moving vehicle forces on bridge structures via moving average Tikhonov regularization. SMART MATERIALS AND STRUCTURES, 2016, 26(8)
• Zepeng Chen, Chudong Pan, Ling Yu. Structural damage detection via adaptive dictionary learning and sparse representation of measured acceleration responses. MEASUREMENT, 2018, 128, pp.377-387
• Yu Zhiwu, Xie Ying, Shan Zhi, and Li Xiao, Fatigue Performance of CRTS III Slab Ballastless Track Structure under High-speed Train Load Based on Concrete Fatigue Damage Constitutive Law. Journal of Advanced Concrete Technology, 2018, 16(5):223-249.
• Zeng Zhi-ping,Wang Jun-dong,Shen Shi-wen,Li Ping,Abdulmumin Ahmed Shuaibu,Wang Wei-dong. Experimental Study on Evolution of Mechanical Properties of CRTS III Ballastless Slab Track under Fatigue Load. Construction and Building Materials,2019,210: 639-649
• Xu Qingyuan, Sun Hao, Wang Lexuan, et al. Influence of Vehicle Number on the Dynamic Characteristics of High-Speed Train-CRTS III Slab Track-Subgrade Coupled System, Materials,2021, 14(13): 3662-3662.]
• Kunlin Ma,Shuangjie Li,Guangcheng Long,Youjun Xie,Lianshan Yu,Qingquan Xie. Performance Evolution and Damage Constitutive Model of Thin Layer SCC under the Coupling Effect of Freeze–Thaw Cycles and Load[J]. Journal of Materials in Civil Engineering,2020,32(6).
• Zhu, KT (Zhu, Kunteng)，Zeng, ZP (Zeng, Zhiping)，Wu, B (Wu, Bin)，Wei, W (Wei, Wei). (2016). Mechanical Property Verification of CRTS Ill Slab Track under Train Load,In: 6th International Conference on Electronic, Mechanical, Information and Management Society (EMIM), Shenyang, PEOPLES R CHINA,APR 01-03, 2016,pp,1464-1469, ACSR-Advances in Computer Science Research

 

Author Response File: Author Response.docx

Reviewer 5 Report

Dear Authors

The paper is very interesting and it possesses sufficient material to be considered as a publication. The Reviewer suggests some minor corrections to be considered in the revised version.

• What is the novelty of the work? This is the main Reviewer’s concern. It is highly recommended that the Authors state clearly the main contribution of this work and pointing out the innovative aspects of this work.
• Figures are not presented in a suitable quality and even size. It is highly recommended to reproduce the figures.
• Please reduce the number of figures if possible. Merge them together and simplify them.
• Please add a table of nomenclature to include all acronyms, symbols and variables.
• How did you obtain material properties presented in in Table 1?
• Regarding the FEM model, please state the FE mesh properties, number of nodes and elements?
• How did you define the boundary conditions in the FEM model?
• Some figures have very poor legend not easy to read the number, specially stress contours. Please correct them.
• Too many subsections, why?
• Please rewrite the conclusions and discussion. Very long! It must be clearly state the outcome of your work. Make it shortened.

Very Best

The Reviewer

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022

Dear Reviewer:

Thank you very much for your attention and the reviewers’ evaluation and comments on our paper “Research on Fatigue Damage Evolution of the Base Plate Structure of CRTS III Slab Ballastless Track under Heavy Haul Train Load”. We have revised the manuscript according to your kind advice. The review comments are in italics, and my answers are in italics.

We sincerely hope this manuscript will be finally acceptable to be published on Applied Sciences. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards

Yours sincerely,

Zhiping Zeng

Please find the following Response:

A point-by-point reply to Reviewer #5

Reviewer: 5

The paper is very interesting and it possesses sufficient material to be considered as a publication. The Reviewer suggests some minor corrections to be considered in the revised version.

1. What is the novelty of the work? This is the main Reviewer’s concern. It is highly recommended that the Authors state clearly the main contribution of this work and pointing out the innovative aspects of this work.

The CRTS III slab has structural stability and good integrity, and it has no obvious weakness. It also has the characteristics of simple structure, high manufacturing accuracy, less surface cracks or no cracks, and small fine adjustment workload. Therefore, this kind of slab is widely used in railways. A large number of tests and theoretical studies have been done at home and abroad on the mechanical properties of heavy-haul railway, CRTS III slab ballastless track and ballastless track of heavy haul railway. However, looking at these research results, there are few reports on the theoretical and experimental studies on the structural mechanical properties of CRTS III slab ballastless track under the action of heavy-haul train, especially for the base plate structure. The study on the fatigue damage evolution of the base plate structure under the load of the large axle load is not only enable the smooth implementation of this type of track for heavy-haul application, but also ena-bles the strengthening and optimization of the track structure form.

2. Figures are not presented in a suitable quality and even size. It is highly recommended to reproduce the figures.

The picture has been changed and rearranged.

3. Please reduce the number of figures if possible. Merge them together and simplify them.

Pictures have been minimized or merged.

4. Please add a table of nomenclature to include all acronyms, symbols and variables.

A table of nomenclature to include all acronyms, symbols and variables has been added at the end of section 1.2.3, seen as Table 1.

Table 1. Abbreviations, Symbols and Variables

	Abbreviation / Symbol/ Variable	Full name / Meaning
Abbreviations	CRTSIII SBT	China Railway Track System III-type slab ballastless track
	CRTSIII BT	CRTSIII ballastless track
	CRTSIII	China Railway Track System III-type
	HHT	heavy-haul train
	SCC	self-compacting concrete
	EMU	Electric Multiple Units
	WJ-8B fasteners	non-separable fastener with iron base plate (iron base plate of type B)
Symbols and variables	D	structural damage
	N	the number of load actions
	Nf	the number of ultimate fatigue loads
		the internal fatigue residual strain
	ε0	ultimate strain
	σs	the stress of steel bar
	fy	Initial yield strength of reinforcement
	fc	design value of concrete axial compressive strength

5. How did you obtain material properties presented in in Table 1?

Since this study is based on the engineering checking project, the elastic modulus, Poisson's ratio and density of each material in the model are provided by the manufacturer, and the support stiffness of the offline foundation is taken according to literature [36]

6. Regarding the FEM model, please state the FE mesh properties, number of nodes and elements?

When meshing the finite element model, the solid element is hexahedron element, the beam element and spring element are two node elements, and the meshing quality is good. The number of nodes is 242553 and the number of elements is 182658.

7. How did you define the boundary conditions in the FEM model?

In order to reduce the influence of boundary effect, the model was extended by the length of one slab at both ends of the studied track slab, base slab and self-compacting concrete finite element model. At the same time, the rail is extended by 100m at both ends of the rail finite element model, and fixed constraints are applied to the ends of the two extension sections.

8. Some figures have very poor legend not easy to read the number, specially stress contours. Please correct them.

有些图片有很差的图例，不容易看懂数字，特别强调轮廓。请改正。

These figures have been refined.

9. Too many subsections, why?

This paper is mainly divided into introduction, indoor test and finite element model calculation, analysis of fatigue damage law of base plate structure, discussion and final conclusion.

In order to facilitate readers to deeply understand the research content of this paper, the introduction illustrates the CRTS III slab track structure and the fatigue damage state of the structure. At the same time, it briefly explains the current international research status of plate track structure, step by step. Then it explains the research necessity, research objectives and research methods of the article, so as to make the article clearer. For the main part of the article, there are many research contents, such as indoor test and simulation analysis. In order to make the test repeatable, the indoor test part introduces the test method and test principle in detail. At the same time, in order to verify the reliability of the model, the experimental data are compared with the numerical results, and the verification conditions are divided into static loading and fatigue loading respectively. Finally, the fatigue damage law of base plate is explored, and the effects of loading position and axle load on fatigue damage are studied. Therefore, in order to make the article more hierarchical and logical, the article is divided into many sections and subsections according to different research contents.

10. Please rewrite the conclusions and discussion. Very long! It must be clearly state the outcome of your work. Make it shortened.

The conclusions and discussions have been rewritten as suggested:
（1）Discussion

The discussion have been replaced with:

From the results performed in this study, the following phenomena can be found:

(1) The acceleration of the base is lower than that of the track slab in the early stages of the train load by half. The isolation layer can effectively reduce the downward transmis-sion of vibration from the upper part of the track structure. However, the increase in the ri-gidity of the fastener and the isolation layer has an adverse effect on the stress of the structural system, especially the stress on the base.

(2) By comparing the displacement and stress under static load and fatigue load, the errors under the two conditions are acceptable and the variation law of the real value is consistent with that of the calculated value, which are similar to those in [41]. Therefore, it can be concluded that the fatigue-loaded finite element model could effectively describe the mechanical behavior of the base plate of CRTS III slab ballastless track structure under heavy haul train force.

(3) As the number of fatigue loads increases, the stress of the structural layer gradu-ally increases, the base concrete gradually damages, and the residual strength gradually decreases. Until the longitudinal tensile stress of the concrete at the mid-span portion at the bottom of the base is equal to its tensile strength, the concrete cracks appear, and then the bottom plate cracks gradually expand from the edge to the center of the plate.

(4) For the tensile stress of the base under the three working conditions, the longitu-dinal tension stress is always greater than the lateral. Hence, it is critical to attach im-portance to the simplified analysis of the longitudinal stress in the structural design. When the load acts on the slab-end sleeper, both the longitudinal and lateral stresses of the base reached their maximum, implying the base at the end of slab is the weak zone. Thus, for the overall design of CRTS III slab ballastless track, it is necessary to strengthen the design of the structural layer at the end of the slab.

（2）Conclusion

The conclusion has been replaced with:
The following conclusion can be deduced:

(1) For the base, the greater the thickness of self-compacting layer, the more time it takes for cracks to appear. Appropriately increasing the self-compacting thickness can effectively delay the time it takes for cracks to appear in the structural layer.

(2) With the increase of axle load, the stress of each structural layer increases, and the damage rate of concrete also increases, resulting in earlier cracks in concrete. An axle load in excess of 35t, has a greater impact on the damage of the base.

(3) When CRTS III slab ballastless track is applied in the heavy haul railway with greater axle load, the thickness of the self-compacting concrete layer could be appropriately increased to reduce the fatigue damage and cracks of the base plate. Also, the concrete level at the end of slab is supposed to be strengthened, and the rebar number in-creased.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

No more commemts, the paper can be accepted in the current form.

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022 

Dear Reviewer:

Thank you very much for your attention and kind advice. Wish you a happy life!

Best regards

Yours sincerely,

Zhiping Zeng

 

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript is a combine experimental and numerical study. I don not believe the manuscript has enough novelty in the present form. I suggest the authors reformat the paper and the presentation style to a scientific journal publication rather than a technical report. Some of the figures are unnecessary and should be deleted. The number of figures are too high. I suggest using schematic figures instead of the screenshots directly from software (Fig 7, 10,  13 and 17). There are a lot of waste space and unreadable information is some other figures (Fig 15, 18, 20,  22, and 24). For example for figure 24, you can make the models horizontal, keep only one color legend and put all the FE results next to each other. Hope this is clear. 

 

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022 

Dear Reviewer:

Thank you very much for your evaluation and comments on our paper “ Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load”. We have revised the manuscript according to your kind advice. The review comments are in italics, and my answers are in roman.

We sincerely hope this manuscript will be finally acceptable to be published on Applied Sciences. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards

Yours sincerely,

Zhiping Zeng

Please find the following Response:

A point-by-point reply to Reviewer #2

Reviewer: 2

The manuscript is a combine experimental and numerical study. I don not believe the manuscript has enough novelty in the present form. I suggest the authors reformat the paper and the presentation style to a scientific journal publication rather than a technical report. Some of the figures are unnecessary and should be deleted. The number of figures are too high. I suggest using schematic figures instead of the screenshots directly from software (Fig 7, 10,  13 and 17). There are a lot of waste space and unreadable information is some other figures (Fig 15, 18, 20,  22, and 24). For example for figure 24, you can make the models horizontal, keep only one color legend and put all the FE results next to each other. Hope this is clear.

Thank you for your review and criticism.

(1) In order to better show the model we established and reflect our workload, Figure 7 still uses the finite element model in the software. Thank you for your advice.

(2) The original Figure 10 has been replaced with:

• Load loading method

(3) The original Figure 13 has been replaced with:

• Loading method

(4) The original Figure 17 has been replaced with:

• Three typical working conditions

(5) The original Figure 24 has been replaced with:

Figure 24. Diagram of calculation of longitudinal tensile stress of base(25t)

The following description is also added:

Due to many working conditions, only the cloud picture of longitudinal tensile stress of base when the axle load is 25t is shown. At the same time, the maximum tension on the longitudinal direction of the base subjected to varying axle loads is indicated in Table 8.

 

Author Response File: Author Response.docx

Reviewer 4 Report

The revised version of the manuscript is better, however, the literature review should be improved taking into account the studies on the railway track systems (not only CRTS). Based on this review, the authors should provide the benefits and drawbacks of the CRTS.

Besides, please avoid Chinese literature because they are not useful for international readers. 

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022 

Dear Reviewer:

Thank you very much for your evaluation and comments on our paper “ Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load”. We have revised the manuscript according to your kind advice. The review comments are in italics, and my answers are in roman.

We sincerely hope this manuscript will be finally acceptable to be published on Applied Sciences. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards

Yours sincerely,

Zhiping Zeng

Please find the following Response:

A point-by-point reply to Reviewer #4

Reviewer: 4

The revised version of the manuscript is better, however, the literature review should be improved taking into account the studies on the railway track systems (not only CRTS). Based on this review, the authors should provide the benefits and drawbacks of the CRTS.

Besides, please avoid Chinese literature because they are not useful for international readers.

• Since the research object of this paper is CRTSIIIslab ballastless track, and now ballastless track has been widely used all over the world, in order to reduce this article’s length, only the development and research of ballastless track are supplemented. At the same time, the advantages and disadvantages of CRTS slab track structure have been illustrated in this paper. The supplemented contents are as follows:

1.1.1 Ballastless track structure

Japan's Tokaido Shinkansen is the world's first high-speed railway, which is a milestone in the history of high-speed railway construction. After Japan, Germany, Britain, China and other countries have carried out research on the slab ballastless track structure[1-4].

The main structural type of ballastless track used in Japan is slab ballastless track, which is mainly represented by Shinkansen slab ballastless track.and it is mainly set in tunnel and bridge sections[5]. The common track forms include ordinary A-type ballastless track and frame ballastless track improved on the basis of A-type ballastless track, as well as G-type ballastless track for special vibration reduction section and RA-type ballastless track laid on subgrade [6]. The slab ballastless track in Japan consists of steel rail, fastener, track plate, CA mortar adjustment layer, convex abutment and base[7]. In order to meet the requirement for different lines, the slab ballastless track structure has different adjustment quantities. Changing the type of fastener is a main way, and the convex abutment also plays a vital role[8].

Ballastless track forms in Germany mainly include Rheda, Zublin, Borg, Berlin, ATD and Getrac. And the types of track structure are integral structure and sleeper-support structure, which are usually laid on the subgrade. The Borg slab ballastless track in Germany is longitudinally connected, which improves the integrity of track slab structure and increases the vertical and horizontal friction[9]. The Rheda type is composed of rails, fasteners, sleepers, concrete slabs and supporting layers.  The track slab is cast-in-situ, which is simple for construction. However, the self-weight is large, and the joint surface of new and old concrete is easy to be damaged[10]. Zublin structure is also a double-block ballastless track, which has strong overall structure, high connection strength of new and old concrete joint surface, high precision of construction mechanization, and good compactness of track bed slab concrete. However, this structure has high requirements for operation, maintenance.

The main representative type of ballastless track in Britain is pact type, which has the advantages of low one-time investment, low maintenance cost and large axle load[11]. Later, the elastic support block ballastless track structure was developed in Britain, which has good vibration reduction effect. Rubber boots are set under and around the sleeper of this structure, and rubber elastic cushion is settled between the boots. Finally, concrete is poured around and at the bottom of the sleeper.

China's research on ballastless track mainly includes three track structures: slab ballastless track, double-block ballastless track and long sleeper embedded ballastless track. CRTSI slab ballastless track adopts unit plate structure based on Japanese ballastless track technology, which is mainly composed of rails, fasteners, track plates CA mortar layer, convex baffle and base, and resin material is poured between track plate and convex baffle[5]. CRTSII slab ballastless track structure is a slab ballastless track developed on the basis of introducing Borg slab ballastless track, which is composed of steel rail, fastener, track plate, CA mortar and base plate[9]. CRTSIII slab ballastless track structure is independently developed and designed by China[12]. The biggest feature is that the limit is realized through boss and groove. These three kinds of slab ballastless track have their own advantages and disadvantages. CRTSI slab ballastless track has the advantages of clear force transmission and easy and rapid repair, but it has obvious weak links, large fine adjustment workload and poor integrity. The CRTSII has good integrity, controllable cracks and high plate manufacturing accuracy, but its inter-layer connection reliability is poor, plate manufacturing process is complex, maintenance is difficult, durability and service life are unclear, and the cost is also high. The CRTSIII has the remarkable characteristics of high safety, convenient maintenance and good stability. It shows obvious advantages over the previous two track plates in terms of structural form, durability and maintenance cost. Therefore, CRTIII slab will be one of the ballastless track types with the most development and promotion space in China. During the field investigation of CRTIII slab ballastless track, some problems were also found. There are through cracks in the track structure, poor bonding and joint separation between the side of the track slab and the self-compacting concrete. As the track slab may be affected by temperature stress, complex temperature environment, train load and other factors during use, the internal structure of the track slab changes, and then the external part of the track slab is bent and cracked. Finally, the track slab structure is separated from the joint, and even the reinforcement bar is blown out. Therefore, it is necessary to further optimize the design of CRTIII slab ballastless track.

 

1. . Derkowski, W, Slaga, L.The Effect of Too Stiff Rail To Base Fastening On Damage Mechanism In RCBallastless Track Structure). Technology News Focus,2020,21(4):1544-1556.
2. . Izvolt Libor,Sestakova Janka,Smalo Michal. The railway superstructure monitoring in bratislava tunnel no. 1 – section of ballastless track and its transition areas. MATEC Web of Conferences,2017,117.
3. . Zheng Weiqi,ShengXingwang,Zhu Zhihui,Shi Tao. Effect of reverse bending deformation of large-span cable-stayed bridge on ballastless tracks' behaviors. STRUCTURAL ENGINEERING AND MECHANICS,2021,80(2).
4. . Zheng Weiqi,Sheng Xingwang,He Hongqiang,Xu Hongyi,Yang Ying. Use of Rubber Mat to Improve Deformation Behaviors of Ballastless Tracks Laid on Bridges. Advances in Civil Engineering,2020.
5. . Zeng Zhiping,Ye Mengxuan,Liu Fushan,Shuaibu Abdulmumin Ahmed,Wang Weidong,Meng Xiaobai. Dynamic response of CRTS I double-block ballastless track under three-dimensional temperature and falling-shaft impact loadings. Advances in Mechanical Engineering,2021,13(3).
6. . Wenner, M,Marx, S,Koca, M.Additional rail stresses due to long-term deformations of railway viaducts with ballastless track - model and reality. Bautechnik,2019,96(9):674-695.
7. . Yang Yang,Zhang Guan Jun,Wu Gang,Cao Da fu. Finite element analysis of ballastless track slabs reinforced with fiber-reinforced polymer bars. Advances in Structural Engineering,2021,24(15).
8. . Wen-Kuei Hsu,Neng-Hao Shih,Yu-Lin Lee,Frédéric Lebon,Raffaella Rizzoni,Manoj Gupta. Railway Continuous Prestressed Concrete Bridge Design in Ballastless Track Turnout Zones. Technologies,2017,5(2).
9. . Chen Zhaowei,Fang Hui. Influence of pier settlement on contact behavior between CRTS II track and bridge in high-speed railways[J]. Engineering Structures,2021,235.
10. . Ramos A ,Correia AG, Calcada R, Costa PA. Stress and permanent deformation amplification factors in subgrade induced by dynamic mechanisms in track structures.International Journal of Rail Transportation,2021.
11. .Robertson,C. Masson,T. Sedran,F. Barresi,J. Caillau,C. Keseljevic,J.M. Vanzenberg. Advantages of a new ballastless trackform[J]. Construction and Building Materials,2015,92.
12. . Zhiwu Yu,Ying Xie,Zhi Shan,Xiao Li. Fatigue Performance of CRTS III Slab Ballastless Track Structure under High-speed Train Load Based on Concrete Fatigue Damage Constitu-tive Law. Journal of Advanced Concrete Technology,2018,16(5).

 

• In order to make the article deeply understood by international scholars, except for some industrial norms, the Chinese literature in the article has been deleted, and relevant international literature is supplemented. Since CRTSIIIslab track is independently built by China, there are no relevant international specifications. Therefore, to increase the persuasiveness and readability of the article, two specifications are still retained in the article.

Author Response File: Author Response.docx

Reviewer 5 Report

Dear Authors

Accepted at this stage. Congratulations.

Best

The Reviewer

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022 

Dear Reviewer:

Thank you very much for your attention and kind advice. Wish you a happy life!

Best regards

Yours sincerely,

Zhiping Zeng

 

Author Response File: Author Response.docx

Round 3

Reviewer 2 Report

I appreciate the time and effort authors devote on the manuscript. My comments are aimed at improving the quality of presentation of the results. Some of my concerns are addressed but I believe some of the figures can be significantly improved. 

Author Response

Title: " Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load"

Manuscript ID: applsci-1479022 

Dear Reviewer:

Thank you very much for your evaluation and comments on our paper “ Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load”. We have revised the manuscript according to your kind advice. The review comments are in italics, and my answers are in roman.

We sincerely hope this manuscript will be finally acceptable to be published on Applied Sciences. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards

Yours sincerely,

Zhiping Zeng

Please find the following Response:

A point-by-point reply to Reviewer #2

Reviewer: 2

I appreciate the time and effort authors devote on the manuscript. My comments are aimed at improving the quality of presentation of the results. Some of my concerns are addressed but I believe some of the figures can be significantly improved.

Thank you for your advice and guidance. According to your suggestions, I have further changed the pictures in the article.

 

 

 

Author Response File: Author Response.docx