Milan Helexa

Dr. Milan Helexa

orcid

Research Focus & Metrics

Academic Career Length

1Year (2026-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
29 December 2023 in Forests
Verified
Journal Article
Open access
PDF file
OMOleg Machuga
Oleg Machuga
Andriy ShchupakAndriy Shchupak
Andriy Shchupak
OSOleg Styranivsky
Oleg Styranivsky
Jozef KrilekJozef Krilek
Jozef Krilek
MHMilan Helexa
Milan Helexa
Pavol FinduraPavol Findura
Pavol Findura
The main tasks of this research are an extended analysis of the technological rut formation process’s geometric, force, and energy characteristics as a result of repeated passage of a forest machine on the soil surface. Existing experimental studies of the rutting process are associated with significant material costs and disruption of the forest ecosystem. The purpose of this study is to obtain similar experimental data in laboratory conditions, as well as establishing the correspondence of these experimental results to the results of field studies. The experiments were carried out on the specialized “soil channel” stand of Technical University in Zvolen (Slovakia), as well as in natural conditions in Brody Forestry of the Lviv Region (Ukraine). Geometric track characteristics were determined by length gauges. Power and energy characteristics of the track development process were determined using dynamometers, ammeters, and voltmeters. The physical and mechanical characteristics of the soil with which the mover interacted were determined by a dynamic hardness tester, a penetrometer, and a moisture meter. The characteristics of rut development processes in natural and laboratory conditions are similar to each other. This makes it possible to carry out a wide range of studies of a wheel with soil on a specialized stand and save considerable money during the implementation of full-scale experiments. So, the process of track development can be analyzed with the help of the geometric, force, and energy characteristics of the “wheel-soil” system obtained on laboratory equipment.

22 September 2026 in Forests
Verified
Journal Article
Open access
PDF file
MHMilan Helexa
Milan Helexa
Jozef KrilekJozef Krilek
Jozef Krilek
Andriy ShchupakAndriy Shchupak
Andriy Shchupak
JKJán Kováč
Ján Kováč
KTKuvik Tomáš
Kuvik Tomáš
MŠMarijan Šušnjar
Marijan Šušnjar
The study analyzes the rut formation process, changes in the physical and mechanical characteristics of the soil, and the energy demand associated with movement of the driven pneumatic wheel during repeated passes on the same track in a laboratory soil channel stand. The tests were performed on a prepared silty loam at an average moisture of 30.64%. Three vertical wheel loads were investigated: 4.84 kN, 6.94 kN, and 8.75 kN without a brush mat, as well as a vertical load of 8.75 kN with a brush mat. After each pass, the average rut depth, its increment, and the average dynamic penetration resistance were determined. For tests without a brush mat, soil shear resistance, power, work performed per pass, and work per 1 m of path were additionally determined. It was established that the rut depth increased non-linearly. The greatest increment was formed during the initial passes, after which the deepening rate decreased. In the tests without a brush mat, the final rut depth showed a trend of increasing with load: 8.1 cm for 4.84 kN, 9.2 cm for 6.94 kN, and 9.9 cm for 8.75 kN. The brush mat was associated with lower accumulation intensity of the rut depth and lower average dynamic penetration resistance in the soil. The change in rut depth is described with sufficient accuracy by a regression model with R2 = 0.9512–0.9761 and RMSE = 0.194–0.344 cm. Energy indicators showed that the first pass was the most energetically intense, and the calculated work characterizes the total work of the wheel movement, not just the work of rut formation. The results confirm nonlinear rut accumulation with the highest increment during initial passes, and the highest energy demand during the first pass. The fitted model provides an engineering tool for estimating permissible pass numbers, while the integrated geometric–mechanical–energy approach offers a more comprehensive basis for planning forestry traffic than conventional bare-soil compaction tests.