Construction and Experimental Verification of Sloped Terrain Soil Pressure-Sinkage Model

Round 1

Reviewer 1 Report

crawler tractors is: metal track tractors

Table 1: Soil particle  size (%)

Powder pratical is: silt (d= 0.002-0.02)

sand grain is: sand

line 153 and along the text soil density 1.5, 2.0 2.5 (g/cm³) is: 1.5, 2.0, 2.5 bulk density 1.5, 2.0, 2.5 (Mg m^-3)

Table 2 and along the text moisture content (%) is: soil water content (%).

Fig. 12. Track shoe model and pressure sensor, it looks like the pressure is not measured under the track lugs but only between the track lugs. It should be noted that the track lugs add a shear strength force which causes further soil compaction.

Author Response

Author Response File: Author Response.docx

Reviewer 2 Report

The article deals with interesting issues in the field of terramechanics, namely the influence of terrain slope and physical parameters of the soil on mechanical changes in the soil, leading to the formation of ruts pushed into the soil when moving machines, in this case special  hillside crawler tractors (HCT). The main visually observable mechanical change in the soil, which the authors observe in their work, is the extrusion of ruts in the soil surface (rut formation) due to the pressure of tractor tracks (caterpillars) and at the same time the effect of these changes in soil on driving characteristics of these machines.

The authors approached the solution very responsibly and well-founded, as they followed the work of renowned authors, such as MG Bekker, but significantly developed their knowledge or methods and included some other factors such as moisture, structure and and soil density and slope. Based on their own methodology, authors created a theoretical mathematical-statistical model, the validity of which was verified by instrumental procedures in laboratory conditions. The created and used methodology is clearly described in the article and its factual content is, in my opinion, correct. In the methodology, the authors effectively use both theoretical principles and instrumental measurements using progressive instruments. The set of figures, graphs and tables presented in the article clearly clarifies the comprehensibility of the methodology, the method of performing experimental tests, as well as the achieved results. In my opinion, the presented mathematical equations correctly capture the essence of the matter and are a suitable basis for the created model. It seems to me to be particularly valuable that the ability of the developed model to predict the formation of ruts in the soil under certain habitat conditions is experimentally verified. The results of the article are therefore both theoretical (scientific) and practical, because they can be used in operational practice when operating tracked tractors in different soil and slope conditions. I consider this fact to be very positive.

I have the following comments or questions about the article:

• in the article quite often there are too long sentences (eg in the Abstract itself), reducing the comprehensibility of the text, therefore I recommend dividing these sentences into shorter sentences - the text will be better understood
• I recommend to check the correctness of the using in the article frequently occurring word "sinkage". As I understand the relevant sentences in the article, this word is intended to denote the formation of ruts pushed into the soil surface by the pressure of the traction mechanisms of tractors (in this case tracks). Wouldn't it be better to use the clearer terms "rut", "ruts", "ruts creation", "ruts extrusion", etc.?
• the influence of the dynamics of tracked tractors and the influence of the width of their tracks on the process of creating extruded ruts in the soil should have been more mentioned in the text
• in the text of the article is in chap. 2 described in detail the methodology of laboratory investigations of changes in soil samples exposed to the pressure of the test specimen. How was the soil in the soil tanks prepared for these tests - was the soil, for example, only is freely inserted into the containers or was it compacted or otherwise modified to simulate the original conditions in the soil in the outdoor environment?
• since I do not know the reality of operating tracked tractors in the given conditions, I ask: if would be expected the tractors travel repeatedly on the same rut, can be this fact incorporated into the model or the model is created only to simulate the consequences of one (initial) travel after undisturbed soil?
• will the created model be refined to the level of a user-friendly software application for the average user, which would, for example, allow the prediction of the optimal time of use of tractors in certain conditions?

Author Response

Author Response File: Author Response.docx