Introduction. Drilling of frozen and permafrost soils is one of the most complicated and energy-intensive processes of earthworks. The current drilling tools are not efficient enough to use since they implement energy-intensive drilling processes and are not always suitable for various types of soil. The use of helical working elements that implement the process of soil destruction with less energy-intensive types of deformations is advanced. The purpose of the research is to study the interaction of a helical blade of a drilling tool with frozen soil.

Materials and methods. The article covers a method for conducting experimental studies of the interaction of a helical blade of a drilling tool with frozen ground and the tested models of the drilling tool. The influence of geometric parameters of a helical drill on a borehole formation process is studied.

Results. The experimental research proved the hypothesis about the possibility of implementing a drilling process with tearing strain and obtaining a borehole diameter larger than a diameter of a destructive section of a helical blade. The dependence of the destroyed soil volume and the relation of an obtained borehole diameter to a diameter of a destroying section of a helical blade according to the angle of bend of a helical blade radius at which its increment occurs is determined.

Discussions and conclusion. It is established that a helical drilling tool performs a borehole drilling due to the tearing strain implementation, which makes it possible to achieve more efficient drilling and obtain a borehole diameter larger than a diameter of the destroying section of a helical blade.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction. In order to the road to be durable at the minimum necessary cost for its construction, the topsoil should be carefully removed without disturbing the soil located under the topsoil. The problem of cheapening the roads construction without reducing their quality can be solved by creating a continuous unit for the formation of the underlying layer. The main working elemens of the unit are shovels. The blade of the cantilever knife fixed on the shovel cuts the topsoil from the bottom. It is located at the angle of 45 ° to the direction of movement of the shovel and also has a sharpening angle. The front angle of the blade of the cantilever knife.

The method of research. The cantilever knife is divided into the elements: the edge of the blade, the upper face of the blade, the surface of the cantilever knife, a lower plane. The consecutive impact of many cantilever knives on the ground within the operating unit width with the ground of one notional cantilever knife at a distance necessary for the excavation of one cubic meter of soil was replaced. The interacting forces of a notional cantilever knife with soil are called notional forces. The methodology of calculating energy costs when penetrating the edge of the blade of the cantilever knife into the soil is presented: to separate a layer from the body of the soil, to create a gap in the body of the soil, to overcome the friction of the soil against the edge of a blade of a cantilever knife. The total energy consumption during the interaction of a edge of a blade of a cantilever knife in the soil excavation with a volume of one cubic meter was obtained by adding the particular energy consumption.

Results. Based on the developed calculation method, the distance at which a cantilever knife has to move to excavate one cubic meter of soil, and the time of this movement determined. The energy costs are calculated when penetrating the edge of the blade of the cantilever knife into the soil: to separate a layer from the body of soil, to create a gap in the body of soil, to overcome the friction of the soil against the edge of a blade of a cantilever knife. The total energy consumption and their structure during the interaction of the edge of a blade of a cantilever knife with the soil during the soil excavation with a volume of one cubic meter are determined.

Conclusion. The total energy consumption during the interaction of an edge of a blade of a cantilever knife with the soil during the development of soil with a volume of one cubic meter is about 7 thousand J/cubic meter. In the energy costs structure during the interaction of an edge of a blade of a cantilever knife with the soil, energy costs prevail to overcome the friction of the soil against an edge of a blade. To determine the total energy consumption for cutting soil with cantilever knives shovels of the unit for removing the upper soil layer from the underlying layer of a road, it is necessary to analyze the interaction of other elements of cantilever knives with the soil.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction. To improve the vibrating rollers in order to increase sealing capacity, reliability and vibration safety, the interaction of vibrating roller parts between each other and with compacted soil is simulated mathematically. The developed models are validated, i.e. compared with the results of experimental studies. However, the known results of experimental studies were obtained based on a relatively small list of vibrating roller models and soil types, as well as in a steady vibration mode. The paper presents the results of experimental studies, which used a vibratory drum of a roller to study its vertical vibration accelerations both in the steady vibration, as well as transient mode at turning the vibration generator on (speedup) and off (halt). This expands the range of opportunities to validate the existing and newly developed mathematical models.

Materials and methods. Experimental studies of vertical vibration accelerations of a drum were conducted using the DM-617 vibrating roller when compacting natural sand-gravel aggregate. The accelerometer readings show high-frequency harmonics, which makes it significantly more difficult to determine amplitude values of vibration accelerations, therefore a low-frequency filter with a boundary frequency of 200 Hz was used for digital processing.

Results. It was determined that when the DM-617 vibrating roller is compacting soil with maximum driving force within the range of variation of dynamic modulus of soil deformation E_vd=14…25 MPа, amplitude values of vertical vibration accelerations of the vibratory drum are from 65... 77 to -61... -69 m/s2 . At the start-up (speedup) of vibration generator, acceleration amplitudes are 1.1 times higher than vertical accelerations of steady operation mode of the vibrating drum and practically do not depend on the dynamic modulus of soil deformation E_vd. At turning off (stop) of the vibration generator, amplitude of vertical accelerations do not exceed the vertical accelerations of the steady operation mode of the vibratory drum.

Discussion and conclusion. The vertical acceleration amplitudes of vibratory drums of DM-617 do not depend on the dynamic soil deformation modulus E_vd, and this is consistent with the results of experimental studies of the vibratory drum mounted on DM-614. The obtained vertical vibration accelerations of the drum mounted on DM-617 in the steady vibration mode, as well as at switching the vibration generator on (speedup) and off (halt) make it possible to verify the existing and developed mathematical models of interaction of vibrating rollers with compacted soil.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction. The article is devoted to the research results on cutting resistance of a road asphalt concrete in the process of the removal of worn coatings by the working elements of milling machines. The relevance of the work is due to the occurring of new brands of asphalt concrete alongside with the use of new types of cutting elements, for which it is difficult to predict the load on the working element when solving the problems of designing new ones and substantiation the operating conditions of the current machines. The purpose. The objective of the study of the interaction of a single cutting element of a road mill with a material at the best fit of speed and geometric parameters of a cutting process with real machines is solved.

Materials and methods. The experimental work was carried out by determining the tangential component of a cutting resistance strength, as well as the work of this strength on a pendulum desk using a unit recording equipment. Four different types of asphalt concrete were being destroyed. A two-factor experiment was conducted for each type of the material. The tangential components of a cutting resistance strength depending on the thickness of the cut chips and the temperature of the material were evaluated.

Results. As a result of the experiment, the data were obtained that make it possible to reasonably determine the loads on the teeth of road milling machines, to determine a power capacity of the process and the drive power of the working element. It was found that the growth of the tangential component to a cutting resistance strength occurs quite intensively alongside with an increase in the thickness of the cut chips, only at the initial stages of the penetration of the cutter. With an increase in the thickness of the cut chips, the growth of the tangential component to a cutting resistance strength does not occur so intensively. In all cases the temperature of the material has an impact on the value of a cutting resistance strength, but this effect is less significant for asphalt concrete with a higher crushed stone content.

Discussion and conclusion. The obtained data make it possible not only to determine the tangential strength to cutting resistance on the cutting elements of the working element of the milling machine, but also to find rational ways to place the cutting elements on the working element, as well as to determine the rational operation conditions of the current and new machines. This is possible when using the results in a mathematical model that describes the operation of the milling working element as a whole.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction. During the construction of modern highways, much attention is paid to compaction of bases consisting of natural soils. They require the use of special equipment, including self-propelled machines, performing compaction in a continuous cycle. But when designing it, certain difficulties arise in determining the parameters of impact accelerators and the mass of the impact plate. The purpose of the work is to study the influence of the parameters of working equipment on the process of soil deformation.

Materials and methods. To check the influence of the parameters of the tamper equipment on the compaction process, a method of mathematical modeling of the process using rheological models was chosen. The working cycle of impact ramming is divided into four phases. A mathematical description of the movement of the stamp and soil in each of the phases of movement is given. The change in the stress condition in time in the body of the soil half-space is considered.

Results.Тhe time dependence of the soil stress condition was obtained for different stiffnesses of the spring impact accelerator and the change in the stamp mass. A joint analysis of the obtained dependencies showed that when designing impact equipment intended for compaction of naturally occurring soils, it requires matching the peak stresses from the mass of the stamp and the stiffness of the impact accelerators. This will make it possible to stretch the action of stresses in time, to form a compacted core in the soil half-space quickly and require a smaller number of strokes on one track to obtain the required material density.

Discussion and conclusion. The proposed model of tamper equipment made it possible to consider the processes occurring in the soil half-space, to obtain comparative characteristics of the stamp mass and the rigidity of impact accelerators. The obtained data correlate well with the data of other authors. The results of the study may be useful to engineers involved in the development of new techniques of intensifying action.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction. Due to the development of building and transport construction in the Republic of Tuva, a lack of capacity of an equipment fleet of ground transportation and technological machines is predicted. The condition of cars changes eventually and not for the better. The operability and productivity of equipment decreases, and the costs of measures to maintain it in working condition are constantly increasing. Therefore, the desire for failure-free operation of machines and to increase the duration of its use is understandable. Each enterprise is interested in the efficient use of the current machinery, and operational - especially since the efficiency of its use is the goal of such an enterprise.

Materials and methods. To improve the working capacity and increase the productivity of the equipment, to reduce the costs of maintenance and repair activities a methodology of optimizing the process of forming an equipment fleet of ground transportation and technological machines in the Republic of Tuva has been developed in this article. The methodology consists of three blocks - “The analysis of a regional equipment fleet of ground transportation and technological machines”, “Modeling the processes of updating the equipment fleet of ground transportation and technological machines” and “Research on processes to ensure the operability of the equipment fleet of ground vehicles transport and technological machines”.

Results. The modeling result is the formulation of recommendations on updating the equipment fleet of ground transportation and technological machines and on the formation of a system for ensuring the operability of the equipment fleet of ground transportation and technological machines considering the planned update.

Discussion and conclusion. Estimated ratios are obtained for assessing the losses of enterprises due to insufficient equipment level of ground transport and technological machines.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction. The emphasis is placed on the development of road transport in the Russian Federation, which is characterized by an increase in traffic carried out by specialized rolling stock of various sizes, a change in the location of cargo-forming and cargo-absorbing points, and the requirements of customers for quantitative and qualitative indicators established in agreements. These conditions ensure to the development of the Russian economy in social significant branches. The purpose of the study is to develop a methodology for the current planning of the operation of specialized rolling stock of standard sizes of a motor transport enterprise to implement the conditions of contracts for the transportation of goods in the city.

Materials and methods. The current planning methodology has been developed as part of a new concept, which is a synthesis of the methods of the theory of road freight transport, the theory of maintenance and current repair of rolling stock. A system analysis, the methods of probability theory and mathematical statistics are used in the studies.

Results:

- the methodological foundations that made it possible to develop a methodology for the current planning of the work of a specialized rolling stock of standard sizes for a motor transport enterprise to implement the contracts conditions for the transportation of goods in the city;

- a computer program, the use of which in the operating of a motor transport enterprise will make possible to carry out planning aimed to implement the contracts terms and make a profit.

Discussion and conclusions. The implementation and testing of the current planning methodology for the transportation of goods in the city is carried out in the conditions of a motor transport enterprise in the city of Omsk using a computer program “Planning the work of a motor transport enterprise for the transportation of goods in the city”. A methodology application allowed the motor transport enterprise to make a profit of 14.5% more than the profit that could be obtained by using previously existing methods in planning.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest

Introduction. One of the most important parameters of the transport system is the capacity of line, which in urban public transport system is usually determined by the stop points throughput capacity. When determining the throughput capacity of stop points, it is necessary to consider the random nature of the transport flows at the stop and the process of boarding and alighting passengers. In this work, the stop point is considered as a multi-channel single-phase queuing system (QS). On this basis, an approach to determining the throughput capacity of stop points in urban passenger transport is proposed and justified.

Materials and methods. Two mathematical models of a stop point as QS are considered: analytical and simulation. Based on the obtained analysis results from these models, recommendations are offered for calculating the actual throughput capacity of a stop point.

Results. In this article, as example a specific stop points are taken, to evaluate the performance of the proposed mathematical models and formulate recommendations to determine its throughput capacity.

Discussion and conclusion. The proposed procedure for determining the stop points throughput capacity, consisting of identifying critical stop points with the highest passengers traffic, determining the service process parameters of fleet, and calculating the probability of queue occurrence, allows to set the maximum traffic intensity for the lines of urban public transport.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction. The priority area of transport systems development is the formation of transport corridors with multimodal systems and intermodal cargo delivery technologies, ensuring the achievement of economic, social and environmental goals facing the countries. For the transport system of Russia, which claims to advance transit cargo flows through its territory, the solution to the above problems can be achieved by organization of the piggyback transportation. A necessary condition for the organization of effective piggyback transportation in domestic and international traffics is the systematization of parameters and the assessment of technical compatibility of the involved rolling-stock.

Methods and models. A systems approach is used to represent piggyback transportation as a complex technical system consisting of road vehicles, domestic and foreign railway rolling-stock interacting in intermodal terminals. The ER-model is used to describe the conceptual scheme of the piggyback system.

Results. The parameters of the road and railway rolling-stock are justified and systematized, their mutual influence is determined at the level of compatibility of their technical and operational parameters in the organization of domestic and international piggyback transportation. Systematization, structuring, storing and updating of rollingstock parameters are carried out using the database «Determining the rolling-stock basic parameters of piggyback delivery systems» developed in Microsoft Access.

Conclusion. The developed system of parameters allows to assess technical compatibility of road and railway rolling-stock of the countries participating in piggyback transportation, and can also be used for unification of intermodal transport units and harmonization of the overall weight restrictions on the road and railway networks.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction: The development of effective structural materials with improved acoustic characteristics is relevant for the modern construction industry. Considering the variety of international building standards for acoustic insulation and soundproofing of buildings, it is essential to systematize the modern methods of studying these characteristics. The purpose of the study was a comprehensive review of methods for determining acoustic characteristics in construction, as well as an analysis of literature and international standards to improve the health and comfort of the urban population.

Main part: Due to the variety and complication of the study of the acoustic characteristics of buildings, premises and individual walling, the article provides an analysis of methods for evaluating these characteristics. The limitations on the size of rooms and sound frequencies for measuring reverberation time have been identified. The process of improving the method of measuring acoustic impedance in Kundt’s tube is shown. The methodology for determining the numerical parameters of sound insulation in buildings using the study of building envelopes taking into account the spectra of various noise sources located inside and outside the building is considered in detail. It was found that existing methods for measuring impact noise show poor reproducibility in the low frequency range. The analysis of the works proved that the sound reflection characteristics theoretically depend on the thickness and rigidity of the reflecting surface and its surface density.

Conclusions: The scope of building materials with improved acoustic characteristics is quite extensive. Further research may be aimed at improving methods for studying the characteristics of sound absorption and sound reflection.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Introduction. Noise pollution is one of the three most significant environmental disruptions in the world. In urban areas, the main source of noise is road transport, which accounts up to 80% of all noise. Noise protection measures are an integral part of the design both at the feasibility study stage and during a project development. In the conditions of cramped urban development, high density of the road network and the shortage of free territories, it is more appropriate to use noise protection structures in the form of roadside noise (acoustic) screens - vertical walls that are installed as close as possible to the highway. However, as the experience has shown, in operating conditions, noise screens do not always fully fulfill their protective function. This article presents a critical analysis of the effectiveness of the noise screens installation on the example of a traffic interchange on 15th Rabochaia in Omsk.

Materials and methods. The evaluation of the effectiveness of the design solutions for the installation of noise screens and the execution of these solutions was carried out with two methods. The first method is calculating. The calculation of the noise impact from the traffic flow on the residential development was carried out according to the methodology of ODM 218.2.013-2011 the Guidelines for the protection from traffic noise of territories adjacent to the roads. To perform the calculations, the content and intensity of the movement of transport at each section of the interchange was determined. The geometric parameters on the object are set. The second method is experimental. To confirm the calculation results, the full-scale measurements of the noise level at nine points at the indicated interchange were carried out.

Results. Based on the results of the calculation it was concluded that the current noise protection structures do not fully fulfill their function. A residential development in the area under consideration is located in the noise discomfort zone. The results of field measurements are confirmed by calculated data. The article gives recommendations for correcting the shortcomings made in the design and construction of the noise screens.

Conclusion. Considering the results of the research presented in this article and published earlier, it is advisable to consider the reconstruction of the transport interchange on 15th Rabochaia street in Omsk.

Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.