Verification of Longitudinal Level Irregularity Suppression Effect at the Structural Boundary by Ballasted Ladder Track

Round 1

Reviewer 1 Report

1) The authors indicate that the use of Ballasted Ladder Track reduces vibrations and increases the durability of the structure in relation to the PC sleeper. The introduction lacks works that talk about the use of USP pads and UBM mats in conjunction with a PC sleeper for the same purpose. USP pads and UBM mats can significantly reduce the value of loads transmitted to the ballast and reduce the phenomenon of grain cracking. In the introduction, please pay attention to the works - for example:

a) https://doi.org/10.1016/j.treng.2021.100093

b) DOI: 10.24425 / ace.2020.131786

c) https://doi.org/10.1016/j.soildyn.2020.106265

d) DOI:10.3390/ma14020313

e) DOI:10.3390/ma13112438

f) http://dx.doi.org/10.1016/j.soildyn.2012.06.014

g) DOI:10.2478/ace-2018-0070

h) Indraratna, B., Nimbalkar, S., Navaratnarajah, S. K., Rujikiatkamjorn, C. & Neville, T. (2014). Use of shock mats for mitigating degradation of railroad ballast. Sri Lankan Geotechnical Journal - Special Issue on Ground Improvement, 6 (1), 32-41.

 

2) Authors should refer to whether the use of USP pads or UBM mats makes sense with Ballasted Ladder Track and what impact it will have. Will the USP pads cover the entire bottom of the ladder sleeper or just the longitudinal bar?

Minor editorial errors:

1) Wrong notation: it is "φ4.22"; should be: "φ = 4.22"

2) Fig. 1 - no dimensions [mm]

3) No citation of documents in References - eg JIS E1201; JIS E 1101

4) Tab. 1. Rail: "50 kgN" - shouldn't it be "50 kg / m"?

5) Tab. 1. Wrong entry: it is "φ2.9"; should be: "φ = 2.9"

6) Fig. 17 - Japanese markings

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In this manuscript, the authors proposed a new type of sleeper for the light railway, the ladder sleeper. Using full-scale model tests were conducted to quantify the vibration transmission reduction effect of the ladder sleepers, and numerical experiments were carried out using a three-dimensional numerical analysis model. However, some suggestions should be considered.

1. The abstract is too long, and the introduction is repeated, should be simplified;
2. The sleeper's first mode is 79Hz. Will wheel-rail resonance be aroused?
3. In Figure 7, First mode was 75Hz, but the text was 79Hz, why?
4. How is the response magnification calculated?
5. The verification of light rail transit mainly in this paper, please to be clear.
6. How to consider the rail irregularity in Part 4?
7. Stiffness and its change rates are an important index of at the Structural Boundary. Why not consider?

Author Response

Please see the attachment.

Author Response File: Author Response.docx