Rut Formation Research Articles

Підвищення колієстійкастосування армуючих синтетичнихості та довговічності асфальтобетонних покривів на автомобільних дорогах і автодорожніх мостах з допомогою з матеріалів ADFORS GLASGRID

Introduction. One of the most common defects in the asphalt concrete pavements of highways and highway bridges that arise during their operation is the formation of ruts. The problem of increasing the rut resistance and durability of asphalt concrete pavements of highways, city streets and roads, at intersections, in front of traffic light intersections, at public transport stops and on the right lanes of bridges and overpasses is very relevant all over the world. One of the effective means of solving this problem is to increase the rut resistance and durability of asphalt concrete pavements by reinforcing them with Adfors GlasGrid® reinforcing synthetic materials.

Temperature Effects on Traffic Load-Induced Accumulating Strains in Flexible Pavement Structures

AbstractRutting is a major distress mode in flexible pavements, results from the repetitive loading caused by traffic movement. Pavement deformation consists of both recoverable (elastic) and unrecoverable (plastic) components. The continuous movement of vehicles contributes to the overall deformation in the flexible pavement system, involving all pavement components. In regions with hot climates or in the hot summer season, rutting tends to be more prominent due to the substantial reduction in the viscosity of the asphalt binder. This decrease in viscosity, which is inversely linked to rutting, occurs as temperatures rise, leading to a heightened susceptibility of the Hot Mix Asphalt (HMA) blend to rut formation. However, according to studies, a significant amount of permanent deformation takes place in the unbound layers beneath the asphalt course, it is therefore essential to prioritize attention on these layers. Temperature exerts besides viscosity a substantial impact on asphalt stiffness, leading to the transfer of higher vertical deviatoric stresses to the unbound layers beneath the asphalt course (base, subbase, subgrade). This research presents a study integrating the High Cycle Accumulation (HCA) model into a laminar model to determine permanent deformations in the unbound granular layer of flexible pavements and taking into account the temperature dependent stiffness of asphalt. Rutting depths at the end of the design lifetime were computed, accounting for seasonal stiffness variations. It was shown that the softer asphalt behavior significantly increases the development of ruts in the underlaying soil layers. The findings were compared with results obtained from mean annual temperature and the typical equivalent asphalt stiffness utilized in fatigue tests. Additionally, an analysis was conducted to assess whether the timing of road implementation influences settlements throughout the design lifetime. The results suggest that the sequence of seasons is most relevant during the first year of service, showing a distinct effect at that time. However, with a higher number of axle passes, the initial differences fade away, and the curves start to merge.

The impact of autonomous vehicles on the performance of steel bridge deck pavement

The widespread application of autonomous driving technology has become a prominent trend in the transportation industry. The purpose of this study was to investigate the impact of the lateral distribution pattern of autonomous vehicles (AVs) on steel bridge deck pavements (SBDP), with the aim of providing reliable theoretical support for future bridge deck pavement management and operation. A mixed traffic flow lateral distribution model was established and the Nanjing Yangtze Fourth Bridge was used as a case study. A corresponding finite-element model (FE) was constructed and Abaqus FE software was used to analyse rutting depths under different scenarios. The simulation results demonstrated that, under the zero distribution mode, a rational layout of AVs can significantly alleviate rut formation. Conversely, an unreasonable layout will reduce the service life of SBDP. Comparing the lateral distribution patterns of different vehicles, both the normal distribution and uniform distribution patterns exhibited positive effects on the SBDP. However, there was no significant difference in the magnitude of this positive impact between the two modes. This research not only fills the gap in the study of AV impact on SBDP but also proposes management methods for AVs.

Field and Laboratory Research of the Rut Development Process on Forest Roads

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.

A comparative study on rutting behavior of unbound and cement stabilized base layers in flexible pavements

Rutting distress, a phenomenon characterized by formation of ruts in high-stress areas of flexible pavements, necessitates material enhancements due to increased vehicular loads resulting from national and international trade via highways, highlighting the need for revised prediction methods utilizing laboratory tests with standardized protocols to evaluate asphalt mixtures before field application. While pavement construction consumes substantial non-renewable resources, there's an increasing emphasis on sustainability over initial costs in government decision-making, underscoring the importance of sustainable development to reduce investments and preserve natural resources. Notably, cement-treated bases are effective in extending the fatigue life and reducing cracking in flexible pavements. Various testing devices, such as the Georgia loaded-wheel tester, French wheel tracking tester, Hamburg wheel-tracking device, and asphalt pavement analyser, assess asphalt mixture properties, but mainly target bound bituminous layers. This study's primary goal is to compare the rutting performance of two pavement sections using a novel device called the 'Roller compactor cum rut analyser' (RCRA), capable of compacting and analysing all layers of flexible pavement. By applying the RCRA model, the research demonstrates that the section with cement-stabilized layers displays enhanced resistance to rutting and deformation, providing valuable insights for the construction of durable road infrastructure.

Classification of road sections according to the degree of danger to the formation of a wear track

Introduction. The intensification of the motorization of the Russian population has led to a significant increase in the number of passenger cars, which in many regions are supplied with studded tires for the winter period. This circumstance led to the large-scale appearance of a certain type of ruts caused by the wear of asphalt concrete pavement from the action of studded tires and abrasive materials used to combat winter slipperiness. The track formed on the surface of road surfaces has a complex character and includes three types of tracks: structural, shear track and wear track. The contribution of each type of track to the total depth of the complex track is different and depends on the characteristics of transport loads, the properties of the coating material, and weather and climatic factors.Materials and methods. The wear track is formed in winter from the impact of studded tires, and its depth is affected by many factors: the mode and intensity of movement of cars with studded tires, the type of spikes, their number on the tire, the size of the protrusion of the working insert of the spike, the properties of asphalt concrete pavement, weather and climatic factors, as well as winter road maintenance measures. On curves of a small radius, braking or acceleration sections, as well as sections with a normal mode of movement of cars, the horizontal loads from the studded tire are different. This is due to the occurrence of various types of friction, as well as the dependence of the coefficient of adhesion of the coated tire on the speed of movement, which is variable in the braking and acceleration sections. As a result, in certain areas, the contribution of wear to the depth of the complex track is greater than in areas with a different driving mode. In the article, a study was conducted to determine the susceptibility of road sections with different traffic modes to the formation of wear ruts. A method has been developed for calculating various components of the complex trackage caused by compaction and wear of the asphalt concrete coating, as well as deformations of the underlying layers of the pavement and the roadbed.Result. Based on the data of experiments carried out on the roads of Omsk, a classification of sections according to the degree of danger to the formation of a wear track is proposed, dividing sections of urban roads into heavily worn, worn and weakly worn. Based on the analysis of data from road diagnostics performed over the past five years, the approximate service life of the coatings until the formation of a 30 mm deep track has been determined.Discussion and conclusion. The authors’ ideas about the influence of friction and the speed of movement on the process of track formation caused by wear are presented. The correspondence of the experimental data obtained by the authors of the article with the data of colleagues who performed similar studies in Russia and abroad is shown. Clarifications introduced by the authors into the generally accepted ideas about asphalt wear are explained.

From the material behaviour to the thermo-mechanical long-term response of asphalt pavements and the alteration of surface drainage due to rutting: a sensitivity study

ABSTRACT In this contribution, a simulation chain for the thermo-mechanical and hydromechanical analysis (surface drainage) of a pavement structure during its whole service life is applied to a typical asphalt pavement (Bk100) used for motorways in Germany. Transient load signals for each tyre position of a truck-trailer combination (vehicle) are generated from a multibody analysis of the vehicle driving on a motorway with rough pavement surface. Material model parameters are derived from experimental identification tests of asphalt materials. The model parameters are used together with a continuum-mechanical description of the asphalt material representing the thermo-mechanical material behaviour at the material scale. The material response of the pavement layers is integrated on the structural scale by using the finite element method (FEM) in combination with an arbitrary Lagrangian-Eulerian (ALE) formulation and equivalent tyre loads of a representative, finite element (FE) discretised truck tyre rolling on an FE discretised pavement section. Different scenarios of rut formation are computed by varying different influence factors (climate temperature, vertical tyre force, type of asphalt material of the surface layers etc.). During the subsequent hydromechanical analysis of the pavement, the simulated deformed geometry of the pavement surface is used to numerically compute surface drainage characteristics.

Application of Lightweight Deflectometer to Assess Structural Competency of Nontraditional Airfield Pavements During Contingency Aircraft Operations

This paper discusses the use of the heavy and light weight deflectometer devices, hereafter referred to as HWD and LWD, respectively, to monitor the structural condition of airfield pavements during aircraft operations at contingency environments. Four airfield pavements like those encountered at contingency environments, referred to as nontraditional airfield pavements, were selected to conduct accelerated pavement traffic testing with simulated C-17 and C-130 aircraft. Pavement rut development was monitored, and both HWD and LWD tests were also conducted at selected traffic intervals. Both HWD and LWD were capable of tracking the pavement deterioration under accelerated traffic testing, which indicates that the LWD could be considered a potential rapid and practical pavement evaluation tool for nontraditional pavements during contingency aircraft operations. Based on current rutting failure threshold, a termination criterion in relation to a reduction in the stiffness parameter from the LWD test could be preliminarily used to aid in expediently determining acceptable aircraft operations on nontraditional airfield pavements. The influence of key operational parameters such as base plate dimension, the depth of influence from the impact force, and pavement rut formation must be further investigated to improve the effectiveness and applicability of the LWD test for nontraditional airfield pavements. The results from this study could be of interest to other low-volume road applications such as in agriculture, oilfield, large construction sites, and mining where pavement evaluation and management practices could be improved with the use of practical tools such as the LWD during the operations of heavy equipment or machinery.

ДОСЛІДЖЕННЯ СТІЙКОСТІ ДО УТВОРЕННЯ КОЛІЇ ТЕПЛИХ АСФАЛЬТОБЕТОННИХ СУМІШЕЙ НА ОСНОВІ БІТУМУ З ВИКОРИСТАННЯМ ЕНЕРГОЗБЕРІГАЮЧИХ ДОБАВОК ТА СПІНЕНОГО БІТУМУ З ДОДАВАННЯМ РЕГЕНЕРОВАНОГО АСФАЛЬТОБЕТОНУ

Introduction. The article investigates asphalt mixtures produced by standard technology according to [1, 2] and the so-called warm asphalt mixtures produced at reduced process temperatures based on bitumen with the addition of energy-saving additives and foamed bitumen. Problems. The resistance of asphalt mixtures to rutting is a key parameter in the design of the mixture, as the load on the pavement structure is increasing under current conditions due to the increased transport capacity of new vehicles that can carry loads with higher than standard axle loads. Objective. The aim of the study was to investigate asphalt mixtures made using standard technology according to [1, 2] and the so-called warm asphalt mixtures made at reduced process temperatures based on bitumen with the addition of energy-saving additives and foamed bitumen. Materials and methods. Experimental comparative tests of traditional hot asphalt concrete ASG.Sh.N.I.A.BND 70/100, asphalt concrete using foamed and bitumen, and asphalt concrete based on bitumen with the addition of energy-saving additives were carried out. Results. Graphical dependences of rut formation after more than

Study on Geosynthetics in Pavement Design

Geosynthetic reinforcement is one of the techniques adopted to improve their performance in pavement design.Geogrid are single line and multi-layer materials usually made by extruding and stretching high density polyethylene,or by weaving or knitting and coating high-strength polyester yarns.The resulting lattice structure has large holes that improve interaction with the soil aggregate. Roads having mostly the problems like the formation of potholes, ruts, cracks and localized depression and settlement, especially during rainy season. These are mainly due to the insufficient bearing capacity of the subgrade in water saturated condition.Geogrids are reinforcing elements to strengthen the ground in order to work on very soft and weak ground in the construction of asphalted or unpaved vehicle roads and areas where the high traffic flow is expected.Laboratory and simulated field CBR tests are conducted on soil samples with and without the inclusion of geogrid layer and also by varying the position of it in the mould. Use of geogrid increases the CBR value of the subgrade and thereby reduces the pavement thickness considerably up to 40%.This study will have positive impact as it will be reduce both project and road maintenance costs.

Safety and environmental benefits of intelligent speed bumps

Speed bumps are a common speeding prevention measure used to protect vulnerable road users, i.e. pedestrians and cyclists, near crosswalks in urban areas. They are also used to reduce traffic volumes, prevent overtaking, and allow a change in driving routine. However, conventional speed bumps have certain shortcomings, such as reduced driving comfort for all road users, potential vehicle damage and associated repair costs, delays for emergency vehicles and public transport vehicles, longer travel times and congestion, difficulties with snow removal in winter, the formation of ruts and potholes before or after such obstacles, and an increase in fuel consumption, traffic noise, and emissions of harmful gasses during braking and accelerating. Consequently, in recent years, intensive work has been done to solve the above problems by developing so-called intelligent speed bumps. Although evaluating the performance of these intelligent speed bumps in real-world environments is not yet widely available in scientific research, numerous patents have been filed in this field over the years. This paper provides an overview of several intelligent speed bumps that have been developed in recent years and discusses the results of investigations conducted on one such speed bump that is already widely used in practice.

Influence of Stump-Root System of Trees on Rut Formation During Forwarder Operation on Peat Soils

To explain the soil deformation processes under the influence of logging machines, average values of various indicators are often used. One of these indicators is the rut depth formed during tractor passages. The average values do not fully describe the consequences of passages on the skidding trails, for example, the rut depth varies along the track. This variability includes both random and regular components. The stump-root systems of trees located on the skidding trail and along its border act as a factor that introduces a pattern. To determine the degree of influence of stumps on 8 sections of skidding trails with the length of 25 and 50 m, located on peat soils (the average mass fraction of water is 82.3%), the rut depth was measured at intervals of 0.5 m and the locations of stumps were noted. The resulting arrays of vertical marks represent the microprofiles of the experimental sections. Measurements were taken after 2 harvester passages and 2 forwarder passages. The stumps were divided into two groups: located inside the tractor track and outside it. Statistical processing of the data showed a wide spread of the rut dimensions in each array. Average values at the sections (standard deviations) in cm were: 21.6(17.7); 30.6(21.6); 37.7(22.7); 46(20.3); 36.4(15.0); 36(15.4); 30.6(21.0); 34(21.0). The autocorrelation functions, constructed for the series of values, showed surges with moderate correlation coefficients on the lags where stumps were noted. An increase in stumps per a length unit of the skidding trail shows an increase in the number of such surges. A decrease in the rut dimensions, in relation to the places where the influence of the roots was absent, averaged: in points 0.5 m away from the stump – 44% (22.6); 1 m away – 32% (20.4); 1.5 m away – 22% (14.2). The spatial influence factor of the roots explains 21% of the variability of the rut dimensions along the skidding trail. The factor of the stump location relative to the track is 19%. The combined influence of these factors is 25%. Further identification of regularities in the rut formation processes is associated both with the continuation of studies of the root system influence, but with the inclusion of factors of the stump size and variety, and with the study of the variability of the soil physical properties along the skidding trails, analysing how this is found in the microprofile structure.

Changes in Soil and Vegetation with Different Number of Passes of Wheeled Forestry Equipment (Middle Taiga, Komi Republic)

—Changes in podzolic soils (Albic Retisols) and vegetation after felling blueberry spruce forest in the middle taiga of the Komi Republic are discussed. Changes in the morphological and physicochemical properties of soils after three and ten passes of the forwarder, as well as after ten passes with subsequent leveling of the ruts are characterized. It is shown that the number of forwarder passes is the decisive factor in soil changes. At the site with three passes, the formation of ruts with a depth of 11 ± 3 cm is observed, while at the site with ten passes, the depth of the ruts can reach 66 cm with an average value of 27 ± 4 cm. Leveling of forwarding trails to remove the ruts leads to the greatest transformation of the natural composition of the upper soil horizons over a larger area. A significant increase in the bulk density of the upper mineral horizon of the soil of the trail takes place after three passes. After ten passes, the bulk density of the upper mineral horizon decreases because of its mixing and loosening by wheeled vehicles. At the same time, an increase in the bulk density of the underlying middle-profile mineral horizon retaining its natural composition is observed. The upper horizons of the soil of the trail leveled with the use of an excavator are characterized by a significant increase in the bulk density compared to the initial soil. It was found that the regrowth of the main tree species in the first year after felling is extremely uneven. In the case of a strong clutter on the trails, there is no regrowth, which requires additional measures to improve tree growing these technological elements of felling area. On the leveled areas of the trails, the absence of regrowth in the first year after felling was observed. However, it can be assumed that in the future these areas will be fairly quickly populated with regrowth of tree species.

ПЕРЕДУМОВИ ЗНЯТТЯ ОБМЕЖЕНЬ ДО РУХУ ВАНТАЖНИХ ТРАНСПОРТНИХ ЗАСОБІВ ЗА ВИСОКОЇ ТЕМПЕРАТУРИ ПОВІТРЯ

Introduction. Currently, in Ukraine, there are restrictions on the traffic of vehicles with an actual weight of more than 24 tons and an axle loading of 7 tons during the day at an air temperature above 28 °C, except for vehicles carrying dangerous, perishable goods, live animals and poultry, and as well as transportation related to the prevention or liquidation of the consequences of emergency situations. An air temperature of 28 °C is considered to be the temperature at which the road pavement structure under the influence of dynamic loadings can sharply lose its load-bearing capacity, which is one of the conditions under which a threat to traffic safety is created or roads can be damaged and destroyed. Problem statement. The analysis of the regulatory documentation showed that during designing of pavement structure, the climatic conditions of asphalt concrete performance should be taken into account and pavement must withstand the accumulation of plastic strains in summer, which requires measures to ensure its rutting resistance. At the same time, the algorithm for ensuring rut stability does not exist yet. It is quite likely that this issue can be resolved by performing appropriate research work and implementing harmonized European standards, respectively, by amending the building codes, etc. However, the question arises whether we do not perform the requirements of the regulatory documentation and design the pavement structure without considering the climatic conditions and ensuring the rut resistance of asphalt pavement, or still comply with these requirements, which should be clarified. Objective. Development of criteria for analyzing the performance conditions of asphalt concrete in the pavement structure and ensuring its rutting resistance during operation. Materials and methods. Prerequisites for the establishment of restrictions on the movement of freight vehicles at air temperatures above 28 ° C, analysis of operating conditions of asphalt concrete in the construction of pavement. Results. According to the results of the work, the influence of temperature, bitumen properties and loading time on the change of asphalt concrete properties has been established. Criteria for the analysis of climatic conditions of asphalt concrete have been developed and criteria for taking into account operating conditions have been established. Approximate bitumen grades for ensuring the asphalt concrete rutting resistance have been established on the basis of establishing the relationship between the standard properties of bitumen and operating properties. Conclusions. For evaluation of possible rut formation resistance of asphalt concrete, it is needed to perform an analysis by the bitumen grade in its composition, the total number of passes of vehicles with estimated loadings during the pavement operational term, the category of road, the type of asphalt concrete, the speed of traffic, as well as the year of pavement arrangement. In order to ensure the rut resistance of asphalt concrete, it is advisable to use the established criteria in the future during the pavement design.

Influence of ruts on the physical properties of Gleyic Retisols after logging machinery passage

ABSTRACT Rutting is the main type of deep soil disturbance caused by clear-felling operations. Here, we evaluated basic soil physical properties in ruts at various soil depths after the passage of logging machinery. The present study was carried out in North Eastern Russia. In total, we measured rut depth at 160 points along wheel tracks, and collected soil samples. Samples (n = 420) from two soil horizons (0–10 cm and 10–20 cm) were taken, both from ruts and from undisturbed soil (control). The correlation analysis showed a direct significant relationship between rut depth and soil bulk density (po = 0.662, p < 0.001). An inverse significant relationship was found between rut depth and total porosity (po = −0.667, p < 0.001), and an inverse moderate relationship between rut depth and the porosity of aeration (po = −0.496, p < 0.001). Similar patterns were observed at a depth of 10–20 cm in the soil layer. The Kruskal–Wallis criterion revealed that the change of the physical properties was lowest in shallow ruts (1–15 cm). In all cases, we found that the physical properties of the control differed from the physical properties of middle (15–30 cm) and deep (>30 cm) ruts. Thus, it is necessary to reduce the formation of middle and deep ruts in particular.

The effect of bogie track and forwarder design on rut formation in a peatland

ABSTRACT The effect of forest machinery on the rut formation on extraction trails is an important aspect of forest operations. The aim of this study was to compare how track design and vehicle configuration affects rut formation on straight and curved test trails with no slash mats on peatland. Rut depth was observed from five machine-track combinations on several test plots after several passes and two different trail configurations, straight and curve. The observations (N = 760) were modeled using a mixed model approach to include the variation between the combinations. The results show that rut depth decreases exponentially with soil shear modulus, increases linearly with the number of passes and is not affected with the trail section configuration. The overall coefficient of determination is R2 = 0.55. A first generation Ponsse Elk with Fomatec tracks (EFwo) showed the lowest rut formation, followed by a first generation Ponsse Elk with Fomatec tracks equipped with add-on track shoes (EFw), a Ponsse Buffalo with KOPA high flotation tracks (Kopa) and a Ponsse Elk 10 W with Olofsfors mixed tracks (E10W), while a Ponsse Elk with long wheelbase bogie and Olofsfors high-flotation tracks (LWB) showed the deepest rut formation. Vehicle dynamics on peatlands are still far from being fully understood and the paper highlights the complexity of the interactions of the variables studied while providing a valid modeling tool with applications in planning of forest operations and simulation.

Remote measuring of the depth of wheel ruts in forest terrain using a drone

ABSTRACT Even at a well-managed harvesting site, vehicle trafficking occurs on at least 12% of the area and might cause ruts and compaction. The use of drones for inventory and mapping in forestry is still a new method. The purpose of this study was to develop a method for measuring the size and depth of wheel ruts caused by forest machines in harvested areas, using drones and Structure from Motion photogrammetry. In order to investigate the accuracy of drone photogrammetry, measurements from flight altitudes of 60 m and 120 m above ground level were compared with manual measurements. The same methods were used at a control site on farm land, taking into account the rut depth and the location of the sample surface (close to trees or in a fully open area). No statistically significant differences were found between manual measurements and remote measurements from 60 m or 120 m altitude at the harvesting site (R2 0.77–0.83). At the control site, an underestimation of 2.2 cm of the rut depth was found for remote measurements made from 120 m altitude. The data derived from drone images were able to reproduce the 3D model of surface features, such as bulges and ruts; these measurements were considered to be equivalent to manual measurements. For practical applications, a post-harvest survey using drones could contribute to verifying compliance with international forest certification standards or by private contractors to evaluate rut formation on their harvest sites.

A Visco-hypoplastic Constitutive Model for Rolled Asphalt

Experience has shown that the durability of “high-modulus” asphalts made with modified bitumen is unsatisfactory. The misdirected “development” forced in recent decades necessitates a more accurate understanding of the mechanical behavior of rolled asphalts, i.e., constitutive formulation of a numerical asphalt model. The authors elaborate a numerical procedure to model the visco-hypoplastic constitutive behavior of the rolled asphalts by the appropriate composition of the hypoplastic theory of soil mechanics and, taking into account the existing asphalt models. This proposal is justified because rolled asphalt is nothing more than an aggregate skeleton of mineral origin, the voids of which are filled with high-viscosity bitumen. The model allows to quantify the interaction of the two components, such as the formation of ruts due to pressure on the bitumen, the formation of cracks due to cooling-induced tensile stresses, and the viscous behavior of asphalt. Validity of this complex numerical model can already be considered proven theoretically, but it still needs to be experimentally verified for the viscous behavior. This new constitutive model has important theoretical and practical consequences such as a new visco-hypoplastic model of rolled asphalt as partially saturated granular material with cooling-induced isotropic residual stresses.

Методы борьбы с образованием колеи износа на улицах и дорогах Свердловской области

The article deals with the issues of tracing rut formation on the roads of the Sverdlovsk region under the influence of studded tyres. Possible methods for combating the formation of tracing rut wear under various conditions are given.

The natural recovery of disturbed soil, plant cover and trees after clear-cutting in the boreal forests, Russia

This study aims to determine the impact of forest harvesting machinery on the temporarily moist soil of spruce forests (Picea abies Karst.) during the summer. For research purposes, we investigated 23 sites of the boreal forest in the European North of Russia (Arkhangelsk region) where logging operations had been carried out using harvesters and forwarders (CTL, cut-to-length harvesting). In the 15 years after logging, the sites were monitored for changes in physical soil properties and the depth/width of ruts and vegetation. In freshly cut areas, the depth of the ruts was linked to the amount of logging residue that had been used to strengthen skidding trails. After 15 years, the ruts were smooth but had not disappeared entirely. The average depth of the ruts decreased from 36 cm to 18 cm during the period under review. At a depth of 0-10 cm, the soil bulk density of the section between the control area and the wheel track increased by 19-27% within the first two years. At a depth of 10-20 cm, the soil bulk density only increased by 16-17% within the two-year period. After 15 years, the soil bulk density had decreased to the extent that there were no signs of heavy machinery movement. The natural restoration of vegetation in the ruts was affected by the presence of stagnant water in the initial post-logging period. Ruderal species and species with broad ecological amplitude to environmental factors grew over the skid trails. 15 years after logging, this overgrowth had stabilised, with the biodiversity level in the control area approaching its pre-logging state. Primarily, the renewal of the cutting areas occurred through species such as birch (Betula pendula Roth.) and aspen (Populus tremula L.). The highest amount of undergrowth (more than 30.000 ha-1) was detected 6-8 years after logging. This then decreases in areas that were cut down earlier. There are environmental consequences of clear-cutting (using the CTL system) on temporarily moist soil. To prevent the formation of deep ruts, it is recommended to leave 15-20 kg m-2 of felling residue.