The broad scale of the plan for the development of the Far North, Siberia, provides for the annual development of hundreds of millions of cubic meters of permafrost soils and rocks, most of which require the use of drilling and blasting operations. The most time consuming process of preparing rocks for excavation is the creation of wells. Drilling of permafrost soils, soils with rock inclusions, monolithic and fractured rocks requires careful analysis and detailed calculations for each type of rock. It should also be borne in mind that the harsh climatic conditions of work in the Far North, open mining fields, also imply a significant distance from any settlements, therefore, based on the above factors, special attention should be paid to investigate the problems of mobility and reliability of tractor drilling rigs. This article discusses the use of modern drilling machines, provides a comparison of a tractor drilling rig with a mechanical drive of a drill string with a machine with a hydraulic drive, lists the factors confirming the feasibility of using a hydraulic drive of a drilling string, examines the results of tests of drilling various rocks, as well as the effect of rock structure on vibrations pressure and increase in the flow rate of hydraulic fluid in the drive system of the machine.

The article shows the procedure for determining the values of the stability index of hydraulic structures (earth dams). An approach to the creation of an engineering methodology for carrying out operational calculations for predicting the state of an earth dam under the influence of known characteristics of damaging factors of rapidly developing dangerous natural phenomena and man-made processes is presented. One of the directions of application of the proposed approach is shown — the definition of rational parameters for the protection of hydraulic structures and the development of a plan of measures to achieve them.

Vibrations of construction and road machinery components that occur during their operation are a harmful production factor for machine operators, therefore, their reduction can be considered a very urgent task. The main route of vibration transmission is through vibration isolation systems for the operator’s seat and cab. The easiest and most cost-effective way to isolate the operator from vibration is through his seat by reducing vibration. The simplest and most reliable vibration protection systems with one degree of freedom limited by vertical movements of the chair can be used for the chairs. Vibration protection mechanisms and systems with quasi-zero rigidity are considered promising. They provide constant static force over a certain range of movement of the object. The task of developing mathematical models describing vibration protection systems with quasi-zero rigidity is urgent. In the Matlab software package using the Simscape library for modeling physical elements, a simulation mathematical model of the vibration protection system of a chair with one degree of freedom has been developed. The base of the chair in the developed model performs harmonic sinusoidal movements. The output parameters of the developed mathematical model are the time dependences of the chair coordinates and accelerations. The blocks used in the model are described, the static force characteristics are given, given using the Hermite spline. The model includes a block of hard movement restrictions. An example of using the developed simulation mathematical model of the chair is given. The developed model makes it possible to specify both the dimensions of the quasi-zero stiffness section and the shape of the curves of the force static characteristics of the vibration protection system. It can be integrated into higher level models.

Pallet flow rack is one of the high-density storage systems. One of the main safety elements of the systems is a brake roller. Centrifugal frictional brake is the widely used type of the brake rollers, which used as speed governor for the pallet. The known method of calculation of the pallet speed on the flow rack does not take into account the length of the friction lining. In reality, the contact of the friction lining and the roller shell occurs in an arc that reaches the full length of the lining during operation. The method of calculating the speed of movement of the pallet on a centrifugal friction roller is given, and a calculation formula is obtained that allows taking into account the uniform distribution of the force of the normal pressure along the length of the lining. The results of a comparative calculation are presented, which showed that the speed of the pallet movement when taking into account the length of the lining is lower than the values obtained without taking it into account. It is found that if the lining length is up to 70 mm, it can be ignored in the calculations using a simpler formula, and if the lining length is more than 70 mm, it is recommended to use the calculation formula obtained in the work.

The article presents the results of the experimental study of the motor drum temperature regime of a short belt conveyor. A description of the experimental stand, as well as the equipment used, is presented. The paper describes the test procedure, the initial conditions for testing at each stage. These conditions imply the nature of the change in the initial tension of the belt, the level of conveyor load, design features of the motor drum, in particular the use of a lining or the use of smooth steel shell during testing. The primary results obtained are presented in the form of decoded thermograms of the working area of the motor drum. The generalized processed results of the experimental studies are systematized in the form of graphical dependencies, which are united according to the objects of study: a motor drum, a leaving belt branch, and an entering belt branch. On the basis of the results obtained, the corresponding conclusions are made, which are the law descriptions of the thermal mode of operation with regard to the motor drum, as well as the belt branches in contact with it.

The article proposes a method of structural optimization of the hydraulic drive of mobile transport and reloading rope complexes based on special multi-axle chassis with increased carrying capacity and cross-country ability. At present, this type of technological machines can be considered as a new class of technological overground transport vehicles, which is an effective alternative to stationary freight ropeways for hard-to-reach areas with difficult terrain and, if necessary, the rapid deployment of transport and logistics operations. An algorithm for the formation of the Pareto set is considered, which consists of a variety of alternative versions of the hydraulic drive based on a combination of positive displacement pumps and hydraulic motors of permissible standard sizes. A criterion for choosing the Pareto-optimal solutions of the designed hydraulic drive is proposed, based on three quality indicators — the total mass of the hydraulic machines, the specific power and the efficiency of the hydraulic drive.

Milling units are widely used in the construction and repair of roads. They guarantee high quality of work, have high productivity and make it possible to provide comprehensive mechanization of technological operations. During operation, significant dynamic loads occur in the drive elements and the design of the units, which leads to a deterioration in reliability indicators and a decrease in the technical and economic characteristics of their operation. Improving the reliability and efficiency of milling units is an problem, the solution of which is associated with the opportunity to predict the character and magnitude of the operating loads in the structural elements. The main source of these loads is the working body. At the same time, the forces of external resistance that arise during operation are sharply variable, random in nature. The article presents a method for calculating the spectral density and moment dispersion at the design stage. It takes into consideration the periodic character of the interaction of the cutters with the road surface, as well as random conditions and modes of operation of the milling unit. The article focuses on determining the initial data required for the calculation. The obtained expressions are analyzed and the main characteristic features of the mill loads are considered. The considered characteristics are the initial data for the dynamic analysis of the drive elements and the unit structure, as well as for strength calculations.

The article describes the geological, petrographic, mineralogical and geochemical data confirming comagmatic nature of syenitoid small intrusions and dikes of the Kumbel-Ugam zone of deep faults. Specialty of syenitoids and related metasomatites and hydrothermalites for precious and rare metals is described on the basis of the results of microprobe analyzes of the forms of occurrence, the material composition of minerals, micro segregations of ore-bearing silicon-alkaline fluids and nanocrystallites in them. The results of mass-spectrometric study of syenitoids confirm their metallogenic specialization in noble, rare and rare earth metals.