Traffic noise research in tambov city

Introduction. The problem of traffic noise on the road network of cities is considered. The reasons for the annual increase in the sound level on urban roads in Russia and abroad, as well as the factors contributing to this, are investigated. The purpose of the work: on the basis of the conducted theoretical research and the obtained experimental data, to develop measures that contribute to improving the environmental safety of the city, to build a model of the dependence of the noise level on the traffic intensity, taking into account the peculiarities of the organization of traffic and urban planning in Tambov.Materials and methods. Sound level measurements on the Tambov road network were carried out in accordance with the methodology specified in GOST 20444-2014, which provided for the assessment of the actual noise characteristics of traffic flows (by vehicle type). The measurements were carried out using a noise meter in summer and winter during peak and inter-peak times on weekdays.Results. The study of the noise level on the Tambov street and road network showed an excess of this indicator relative to the norms by 7-18%, depending on peak and inter-peak time, as well as the summer and winter period. The dependence of the traffic intensity of vehicles on the noise level in the summer and winter periods is constructed.Discussion and conclusion. The measures were proposed, including urban planning, to reduce the sound level in the areas under consideration. The complex of these measures will reduce the level of traffic noise on the city’s road network by an average of 5-15 dBA.

Influence of soil moisture on the deformation properties of soil-crushed stone samples during compression

Introduction. The purpose of the article is to determine the dependence of the influence of soil moisture and the content of crushed stone in a soil-crushed stone sample on the secant modulus of deformation under uniaxial compression. The need for such a mathematical model is necessary in order to introduce correction factors to the values of the stamped deformation moduli of the gravel layer calculated from test data delivered at other soil moisture conditions, e.g. for flume or road tests during a non-calculated period of the year.Materials and methods. Cylindrical samples with a height of 20 cm and a diameter of 10 cm were made to perform tests using a large standard sealing device. The content of crushed stone of a mixture of fractions of 5-10 and 10-20 mm varied in the samples. The methods of saturation of samples with water and their testing by uniaxial compression are given. The rules for processing the experimental results are described, which include: correction of the initial part of the graphical dependence of deformation from pressure and statistical processing of the results. The analysis of methods for calculating the deformation modulus, which are classified into three types, is performed: secant module, tangent module and piecewise linear module. Based on this analysis, a method for calculating the deformation modulus of a soil-crushed stone sample under uniaxial compression is justified.Results. The results of experimental determination of the deformation characteristics of soil-crushed stone samples under uniaxial compression are presented. A mathematical model of the dependence of the deformation modulus of a soil-crushed stone sample from the soil moisture and the content of crushed stone used in the soil-crushed stone mixture is obtained.Discussion and conclusions. Recommendations are given on the application of the research results for the development of an album of standard constructions of road pavement of the lowest type in the districts of the Omsk region.

The authors would like to thank the staff of the Organisation of Transportation and Transport Management Department

Introduction. The article is devoted to the lorries work planning, the operational characteristics of which will make it possible to transport loads of different properties due to changes in the design of these vehicles. The purpose of the study is to develop a new scientific and methodological approach for planning the operation of trucks, which allows taking into account the compliance of a) the controlled parameters of the vehicle with the required values when making changes to the design, b) the planned volume of technical impacts to the required volume for the periods of operation of vehicles in certain conditions, c) the volume transportation in the contract for the planned production of vehicles for the transportation of various types of goods.Materials and methods. To plan the work of a lorry, taking into account changes in its design, it is required to use improved methods for optimizing the planning of the work of a freight motor transport enterprise, which is the relationship of activities for the transportation of goods, maintenance and current repair. The basis of the presented materials and methods is the scientific work of domestic and foreign scientists on the operation of cars with changes in its design; the main provisions of the Federal Laws in terms of permits for the operation of vehicles. The methodological basis of theoretical and experimental research is system analysis and logical analysis.Results. The authors have developed a scientific and methodological approach to planning the operation of a lorry, taking into account changes in its design to fulfill the terms of contracts and make a profit for the trucking company.Discussion and conclusions. The implementation and testing of the scientific and methodological approach were carried out according to the algorithm of the developed methodology in the operating conditions of a motor transport enterprise in the city of Omsk. A procedure was carried out to obtain a certificate from the traffic police after changes were made to the design of the KamAZ-53212 vehicle in order to operate it as a dump truck, and a calculation of costs and profits was made to fulfill the terms of contracts for the transportation of various types of goods.

Geometric, kinematic and dynamic parameters of the disc ripper

Introduction. The unit of continuous action for the formation of the underlying layer is designed to increase labour productivity in the construction of roads and other objects, for the construction of which it is necessary to remove the upper layer of soil. For loosening of soil in the unit used bit-like working bodies. Often, disc working bodies are used to cut the soil. Therefore, the expediency of using passive discs in road-building technical means, in particular, in the unit of continuous action for the formation of the underlying layer of highways, is of practical interest. Despite the large number of works, a detailed analysis of the operation of passive disks was not made. Therefore, in order to compare the energy costs for cutting the soil with passive discs and chisel-shaped working bodies, it is necessary to make a theoretical analysis of the operation of passive disks. Analysis of the energy costs of the disk ripper cannot be carried out without having the approximate values of its geometric, kinematic and dynamic parameters.The method of research. As part of a continuous unit to form the underlying layer of roads, each disc would be clamped with soil on both sides and carried out clamped cutting. Therefore, a disk ripper is adopted for analysis, aggregated with a separate energy device. On the basis of the constructive layout, rational geometric parameters of the disk ripper are revealed. The method of calculation of its kinematic and dynamic parameters is developed. In particular, the method of determining the weighted average circumferental velocity of the disk, the angular velocity of the disk and the circumferental velocity of the point on the edge of the disk blade is considered. The modes of cutting the soil by various parts of the disk are considered.Results. On the basis of the developed technique, the dependence of the minimum diameter of the disk on the depth of soil development was revealed. The moment of resistance of the soil to the rotation of the disks is calculated. The horizontal and vertical component of soil resistance to the front disc carrying out clamped cutting and subsequent discs carrying out semi-clamped cutting of the soil are determined. The necessary thrust force of the energy device for cutting the soil with a disk ripper and the dependence of the thrust force of the energy device for cutting the soil on the depth of soil development were revealed. The performance of the unit, including the power device and the disk ripper, is calculated.Conclusion. Since as part of the unit of continuous action for the formation of the underlying layer of roads, the disks will carry out clamped cutting of the soil, for preliminary loosening of the soil with disks, it is more expedient to use a separate unit, including an energy device and a disk ripper. On the basis of the theoretical studies carried out, the necessary thrust force of the energy device for cutting the soil and the total traction force necessary to move the disc ripper were revealed. The performance of the unit is calculated. To compare the energy costs for cutting the soil with passive discs and chisel-shaped working bodies, it is necessary to make a theoretical analysis of the energy costs for the operation of passive disks.

Development of a simulation model of the heating process in the passenger cabin of a vehicle under low temperature conditions

Introduction. A distinctive feature of working conditions in the Arctic territories is the long period of exposure to low temperatures. Passenger transportation by road is becoming one of the key aspects of ensuring the continuity of the production process. The task of delivering workers to the place of work, moving them between work zones during a work shift is solved by using wheeled vehicles of various categories. One of the most widespread types of wheeled vehicles used to transport workers is the M3 category wheeled vehicles with a capacity of no more than 22 passengers. Ensuring the thermal comfort of vehicle passengers seems to be relevant, since ensuring biophysical compatibility minimizes the risks of cold injury by workers and maintains a high level of performance.Materials and methods. The results of the analysis of the Russian and foreign studies in the direction of ensuring thermal comfort and ensuring biophysical compatibility in confined spaces are presented. The results of computer modelling of the dynamics of microclimate parameters in the passenger cabin of a wheeled vehicle of M3 category with a capacity of no more than 22 passengers are presented.Results. The paper presents the results of theoretical studies, microclimate parameters in the passenger compartment of vehicles, taking into account the breathing of passengers and changes in the gas composition of exhaled air. Theoretical studies of the operation of the heating system of the passenger compartment were carried out, taking into account the refined breathing model of passengers. Distributions of microclimate parameters in the section of the passengercompartment were obtained when using a heating system with one heater; the impact of passengers’ breathing on the parameters of the microclimate in the passenger compartment was assessed.Discussion and conclusion. Based on the numerical solution of the system of heat transfer equations, directions for further research and recommendations are formulated to ensure thermal comfort in the passenger compartment of a wheeled vehicle at low temperatures. The materials of the work may be of interest to specialists involved in the design and ergonomics of wheeled vehicles, labor protection.

Сomparative analysis of economic efficiency application of milling excavator working equipment for pipeline undermining

Introduction. The use of pipeline transport for the movement of hydrocarbons and petroleum products is the main strategic system of Russia with a huge volume of cargo turnover. The share of pipeline transport in the freight turnover of the Russian transport system is over 48 %. Maintenance of the pipeline system is impossible without the use of mechanization and special equipment. So, to restore its working condition, various options for sets of machines are used.Implementation of the methodology. As a result of the research carried out, a set of machines was selected for performing the technological operations of the overhaul of a section of the steel main pipeline. The main technical and economic indicators are calculated, taking into account the efficiency and expediency of using a set of machines.Results. The economic efficiency of a set of machines, including a hydraulic excavator with a developed milling working equipment, the novelty of which is confirmed by patents for a useful model of the Russian Federation, has been determined.Discussion and conclusions. The directions of further research are the calculation and substantiation of the necessary operating parameters for the introduction into operation of the milling working equipment of a hydraulic excavator.

Аnalysis of methods of calculating road structures based by shear resistance in the soil

Introduction. Checking the soil of the subgrade and the layers of road pavement made of loosely cohesive materials by shear resistance is one of the three mandatory conditions for calculating road clothing according to strength criteria. The methodology for checking the soil of the subgrade and the sandy layers of the road pavement is constantly being modified, which is why changes concerning certain calculation details appear in each new version of the regulatory document. The purpose of this work is to analyze the advantages of the classical solution of A.M. Krivissky and to reveal the essence of the errors made in subsequent modifications of this calculation.Materials and methods. The analysis of solutions is carried out from the standpoint of compliance with the basics of mechanics. It is shown that the calculation of the total shear stress in the classical solution of A.M. Krivissky is performed in accordance with the principle of force superposition, which consists in calculating the components of the stress tensor from each force (time load and the own weight of the layer materials) separately, followed by summing the corresponding components. In this case, the active shear stresses from the temporary load and the own weight of the materials are calculated as the equivalent stress of the Mohr-Coulomb criterion. The calculation of these two components of the total shear stress is performed at the same value of the internal friction angle. Since the angle of inclination of the sliding surface to the main axes is determined by the sum or difference of 45 degrees and half of the internal friction angle, the tangential and normal stresses, which are components of the active shear stress, both from the temporary load and the own weight of the materials, are determined for the same shear surface rotated to the main axes at the same angle. In the current normative calculations, the active shear stresses from the temporary load and the own weight of the materials are determined at different angles of internal friction. This means that the active shear stresses from the temporary load and the own weight of the materials act on two different shear surface rotated to the main axes at different angles. Such stresses cannot be summed up or compared with each other. In addition to this error of the normative calculation methods, their other disadvantages are given.Results. As a result of a detailed analysis of the known modifications of the classical solution, obvious contradictions to the principles of continuum mechanics are established. As an alternative to modern calculation criteria for shear resistance, the article presents criteria for soil strength in which the shear stress exceeds the equivalent stress in the Mohr-Coulomb criterion. The principle of deducing formulas for calculating the first critical load and the total shear stress from the strength criteria under consideration is shown.Conclusion. Conclusions are drawn about the need to return to the classical solution obtained by specialists of the Leningrad School of the USSR, or to develop a fundamentally new solution based on a new plasticity condition in which the total shear stress exceeds the similar characteristic of the stress state of the original Mohr - Coulomb criterion.

Use of sewage sludge in concrete industry

Introduction. The article deals with the actual problem of disposal of industrial waste (sewage sludge). According to the literature data, possible directions of the use of sewage sludge in the production of building materials are identified and considered. Special attention is paid to the proposed variant of systematization of materials, which is based on the dependence of the aggregate state of the sediment on the type of building material. It is proposed to use sewage sludge as a complex additive to improve rheological properties at all stages of heavy concrete hardening.Methods and materials. Studies of the basic properties of raw materials and concrete based on them were determined using standard methods and the requirements of national standards. The material and chemical composition of the sediments, their physical and mechanical characteristics were determined on the basis of the laboratory of the plant of chemical concentrates (Novosibirsk).Results. As a result of the experimental work, the optimal percentage of sewage sludge in the composition of heavy concrete was determined, as well as the ratio of the chemical modifying additive, the optimal composition of concrete was investigated.Conclusion. As a result of the experimental work, the influence of the introduction of sewage sludge modified with plasticizing additives into the concrete composition was established. It has been established that sewage sludge is advisable to use in heavy concrete as a corrective additive without reducing the strength characteristics. In further studies, it is planned to solve the problems of structure formation and study of the interface between the phases of sewage sludge in the composition of concrete; to investigate the relationship between the chemical composition of precipitation and the physical and mechanical properties of a building material.

Сhanging the lubricity of diesel fuel with vegetable oil additive

Intriduction. The environmental safety of cars with a diesel engine does not lose its relevance. In the conditions of stricter requirements for diesel fuel, the content of many substances harmful to the environment, including sulfur, is not allowed. As is known, low-sulfur fuels require the presence of additives that improve the lubricating properties of diesel fuel. Non-compliance with the requirements for lubricity significantly affects the resource of the fuel supply system of a diesel engine, primarily the Common Rail system. In order with the circumstances listed above, we hypothesized that vegetable oil can serve in small concentrations to improve the lubricating properties of fuels.Materials and methods. In our research, we conducted experiments using the standard HFRR method (highfrequency translational motion of a ball rubbing against a plate in fuel). A microscope was used to visually assess the wear spots and measure their size. Diesel fuel was taken as samples for experiments and vegetable oil was added to it as an additive in certain proportions.Discussion and conclusions. The vegetable oil additive can improve the lubricity of diesel fuel, even if it does not comply with GOST for this parameter. The experiments conducted allow us to conclude that the vegetable oil additive as a percentage of diesel fuel almost linearly reduces the diameter of the wear spot

Estimation of truck reduction factors applicable to calculation of parameters of a regulated intersection

Introduction. The rapid growth of the country’s car park and the increasing rate of traffic volume lead to various types of transport problems. This is especially acute in regulated areas located near logistics parks, as well as in industrial zones of cities. Here, in the general traffic flow, trucks prevail, which differ from passenger cars primarily in their overall dimensions and dynamic characteristics. For the uniformity of the traffic flow, a certain difference is compensated by specialized coefficients of converting to a conventional passenger car. The performed research is aimed at establishing the main methods used in bringing freight vehicles to a conventional passenger car and assessing the current coefficients of converting freight vehicles to a conventional passenger car by determining the value of the reduced traffic intensity.Methods and materials. Within the framework of the study performed, natural methods of data collection were used for the subsequent calculation. When analyzing certain parameters, mathematical models have been established that underlie certain values of the coefficients of converting trucks to a conventional passenger car.Results. In the course of the study, the authors classified the methods for determining the coefficients of bringing a truck to a conventional passenger car. The values of the reduction factors for some of them have been established, which can be used when calculating the parameters of the regulated section. The present value of road traffic on the set object of the study - the regulated intersection - has been calculated using different actuation coefficients established earlier. The results obtained are assessed.Conclusion. The analysis of the values obtained as a result of calculations showed their significant difference from each other with a difference of 12%, 53% and 300% of the value of the total (not reduced) intensity. Based on the results obtained, the main tasks of further research are determined.