D.A. Shibanov’s research while affiliated with Saint Petersburg Mining University and other places

Several studies have been reported about the importance of excavator positioning on open pit. It is essential to study and evaluate the slope stability of non-metallic deposits to understand how various factors affect it. In this work, the relationship between slope stability and the positioning of excavators in non-metallic deposits (as sand and peat) was investigated in order to increase the safety and efficiency of excavators during excavation processes. A two-stage method is proposed. A model of excavator on the pit slope was designed and imported to ''Rocscience Slide 2D'' software with taking all slope parameters constant, except for the slope angle, excavator positioning on the slope and pressure of excavator on slope (NGP). After that the factor of safety value was collected using the Spencer Method. Moving forward with the Two-Level, Three-Factor Full Factorial Design at the Design Expert software to study the effect of each factor on the response variable (FoS), as well as the effects of interactions between factors. The control of NGP value can reduce slope stability in average of 5 to 30% and slope angle can increase FoS by up to 5 to 15%. The study found that rational excavator positioning can significantly reduce the risk of slope failure and improve the overall productivity of the excavation process in non-metallic material deposits. Furthermore, the information obtained could be useful for the development of excavator artificial intelligence systems to control the excavator positioning on open-pit slope and minimize the effect of factor different factor on slope stability.

The article analyses efficiency assessment of mining excavators using the case study of mining operations of the Republic of Uzbekistan. The index of target productivity is used as an assessment criterion, which definition methodology takes into account the negative influence of the operation factors on the value of productivity loss in basic operating conditions. Climate, mining and geological and mining engineering conditions, organization of the mining operations, the quality of the face and rock mass preparation, ergative factor of management as well as maintenance and repair are considered as the impact factors. A weighting coefficient of the impact factor is introduced in order to adjust the value of losses in given operating conditions. The value of the weighting coefficient is justified based on long-term observations of specific conditions features and modes of operation, maintenance and repair of excavators in the quarries of Uzbekistan, expert opinion and open source data. A ray-path chart of the efficiency preservation coefficient of the EKG-20K excavator as a widely used excavator within the excavator fleet renewal programme at Uzbekistan enterprises, was plotted for the worst scenario and for the Kalmakir, Yoshlik and Muruntau open pit mines. As a result, an achievable level of the target productivity of the ECG-20K excavator is estimated for the considered open pit mines.

Assessment of loads at the hoisting and crowding drives of a mine shovel working attachment helps to make a conclusion on the rational paths of the bucket movement in terms of the resource consumption intensity. The first part of the article defined the forces in the hoist winch ropes at the inclination angles of 60°, 70° and 80° relative to the horizon for straightline paths of the bucket movement. It was found that the hoisting force directly affects the crowding force required to ensure the excavation process. The article analyzes changes in the pressure components and defines the values of the pressure force in the main and intermediate positions of the working attachment, as well as the nature of changes in this value. The values of the crowding force for the considered paths of the bucket movement during the bench excavation were found, and it was concluded that the lowest forces are observed at the closest path with the inclination angle of 80° and 70°. The relationship between the hoisting and crowding forces is defined based on the torque values of the motors of the corresponding shovel drives. A complex analysis of the drive operation of the shovel working attachment has been performed, the results of which allowed to determine the basic values of the hoisting and crowding motors operation per cycle for further adjustment of the maintenance and repair intervals.

One of the major tasks in carrying out open-pit mining operations is timely and high quality maintenance and repair of mining equipment, in particular, mechanical shovels, which secures a required availability level. The most loaded are the lift and pressure drives of the shovel's working attachments, which significantly increases the risk of failure of their components. An adequate assessment of the loads acting on these drives through analyzing the changes in currents and voltages of their motors makes it possible to adjust the time between maintenance. In the course of the study, the representative points of the following three lumped working processes were obtained within the working cycle of 26.75 s: excavating; platform rotation with simultaneous movement of the shovel from the upper point of the path to the unloading point; reverse movement of the platform rotation mechanism with the returning and its positioning of the working attachment to the initial position. Changes in forces acting on the ropes of the lifting winch of the shovel were determined based on the evaluation of the obtained layout of the working attachment positions for the EKG-18R mechanical shovel and taking into account the driving and motion resistance forces within the working cycle. Analysis of the obtained force values acting on the ropes of the lifting winch at the three linear excavation paths with the inclination angles of 60, 70 and 80° has shown that the lowest forces in the lifting winch rope occur at the closest path with the angle of 60°. The received data will allow not only to select a rational path and the angle of bench mining, but also to adjust the time between maintenance according to the actual operating time of the lifting, pressure and movement drives.

High quality and timely maintenance and repair (M&R) of mine electric excavators is crucial to minimizing the risks of failures. The article analyzes the significance of factors the influence the failure rate, including such factors as ergatic, technical, climatic, organizational and technological. The analysis showed the greatest criticality of ergatic, technical and climatic factors, with ergatic being the most important of them. The failure rating of mine excavators by the following systems is presented: working attachments, lifting gear, pressure mechanism, traveling gear, hydraulic system, rotation gear and electrical equipment. The most critical are the working attachments, lifting gear and pressure mechanisms, which make up 72%. The principles to design the concept of conscientious maintenance and repair practice (CM&R) are shown. The Fine-Kinney principle is applied in numerical estimation of the failure risks of mine excavators. Digitalization of target operations for electric crawler-mounted power shovels is proposed and a list of coded types of operations is presented for efficient accounting of the maintenance and repair works. The proposed coding system allows systematization of the MRO processes, providing control and their analysis during the whole operation period.

Development and application of digital technologies at the stage of new model design is highly relevant. Manufacture of a testbed vehicle and its full-scale pilot testing is impossible for Russian manufacturers of mining excavators due to a high cost of a prototype and a lack of special testing grounds. In order to reduce the risks of machine builders as vehicle manufacturer and those of MPPs as users of the prototype excavator, it is necessary to introduce and develop the digital twin technology at the stage of designing new models. A general reference point in development of the digital twin of a mining excavator is minimizing human input. Due to integration of works by stages of creation of the digital twin in a form of an information diagnostic system, there is a possibility to manage the life cycle of the product and optimize MRO with accounts of actual conditions and operating modes.