Surveying Tasks Solution Automation in the Framework of Mining and Geological Information System Creation at PJSC "Uralkali"

The results of work on the automation of the solution of engineering problems facing the specialists of mine surveying services of the mines of PJSC "Uralkali" are presented. The developed software modules are fully integrated into the corporate mining and geological information system of PJSC "Uralkali" and are grouped into specialized software systems - automated workstations. These complexes are installed at the workplaces of various mining specialists, from the heads of technical departments to employees of departments at mines. In total, 21 software systems were developed, of which three workstations were created for the specialists of the company's mine surveying service. For the mine surveying departments at the mines, an automated workstation "Local mine surveyor" was developed and put into commercial operation, for the department of capital surveying and geodetic works - an automated workstation "Capital mine surveying", for employees of the department of the chief mine surveyor of PJSC "Uralkali" - an automated workstation "Chief surveyor". The software modules that are part of the automated workstations of the specialists of the mine surveying service allow in an automated mode to solve a wide range of engineering problems, due to the requirements of the current regulatory documents. Among them, one can single out such tasks as: processing the results of instrumental survey of underground and surface objects and, on its basis, replenishment of mining and graphic documentation in digital form (2D and 3D); mining planning and design; preparation, editing and printing of standard technical documentation (payroll, tables, reports and graphics); solving issues of safe mining; analysis of the implementation of planned and design indicators of the mining enterprise, etc.

Mine surveying technique and steel storage tank base deformation removal

Introduction. Vertical steel tanks are extensively used in oil fields to hold crude oil and other liquids. Their construction requires continuous surveying control. However, measurement procedures, data processing, and deviations and documentation correction are not universal and cannot be applied for tanks with a capacity of less than 3000 m3. Moreover, the process of correcting the detected bottom irregularities is poorly substantiated and intuitive. Research objective is to improve the as-built survey accuracy and reliability of the low-capacity steel tank bottom, substantiate the minimum height of its irregularities, increase the objectivity and productivity of measurement processing, develop an unambiguous method for time-predictable correction of bottom irregularities, and substantiate the optimal contents of its relief’s as-built scheme. Methods of research. Geometric leveling for the bottom profile survey failed to provide adequate accuracy and was therefore replaced by the method of trigonometric leveling. A method has been developed for determining the deviations of the existent tank bottom profile from the design position by means of algebraic actions with surfaces of a topographic order. The accuracy of determining the smallest height of bottom irregularities has been estimated under the tacheometric survey. A method has been proposed for controlling the correction of tank bottom irregularities based on evaluation calculations of bottom deformations by the finite element method. Research results. All the development results are exemplified by a specific production example. It was found that for a full completion of work, two iterations of tank bottom irregularities correction are enough. Methods of optimal design for the facility’s as-built schemes are presented. Conclusions. A simple, accurate, low-cost, productive, and time-predictable method of mine surveying, mathematical processing and correction of deviations in the tank bottom profile has been developed. This technique reduces the construction period and increases the operating time of the facility.

Classification system for documents with mine surveying data

All enterprises engaged in exploration activities on the territory of the Russian Federation, are facing the need to formulate tasks for the mine surveyor service and control their execution. It affects enterprise’s workflow process. Due to it, a problem of organization of efficient document processing in electronic document management systems (timely identification of documents containing mine surveying data) takes place. The article presents possible solution of this problem – automated document classification system into EDMS in the form of optional add-on for 1C:Document Management. Within the classification system creation a preprocessing script for primary document texts, including cleaning, lemmatization, stop words removing, as well as preparation of input features for the classifier were developed and implemented. Applicability of different machine learning algorithms to solution of considering classification problem was studied, the values of hyperparameters providing the highest value of the ROC AUC metric were determined. The quality of all obtained models was assessed using metrics Precision, Recall and F-measures, the stability of the classification quality to changes in the input data was investigated. The identified problem of instability of classification results was solved by building and implementing a machine learning model in the form of ensemble of classifiers. Classification model (an ensemble of clusters) was tested on the set of real documents of Gazprom nedra Ltd; classiffication quality on the test sample by ROC AUC metric was 0,91. Except the classification module itself, developed system contains the storage database for learning outcomes, function library for organization of work with the database and API interfaces allowing to process classification requests, coming from external systems. These API interfaces, in particular, implement the ability to load saved trained models, validate data coming from external systems, preprocess input text documents, train new models and assess their quality, save both trained models and the results of their testing. Also the possibility of the additional training of the models on a new data was realized.

Predictive assessment of the stability of quarry sides

The composition of the rocks composing the quarry sides and the approximate slope angles in accordance with the mining and geological conditions are described. The issues of creating observation stations are considered taking into account seasonal temperature fluctuations of the benchmarks. Observation materials are generalized, the degree of danger of deformations is established on the basis of observations of deformation speed. The mining safety control methods are described. The disadvantages of the approach to data processing and analysis are identified. A criterion for mine surveying prediction of the pit wall stability based on the comparison of critical and actual relative deformations is proposed. The purpose of the local forecast of wall deformation is to control the stability of non-working and working slopes of the sides, and to confirm the efficiency of the method used. The predictive assessment was carried out on the shift of working benchmarks on one of the open pits of Transbaikalia. It is suggested monitoring the stability of rocks using oscillograms obtained by seismic equipment.

Navigation system for heading machines in potash mines

Mining operations at potash mines are carried out by heading machines. Setting of a direction and control of the movement of the machines is carried out by the mine surveyor and by the machine operator in the manual mode. The lack of automation of this process during production leads to large labor costs of the mine surveying service, while the experience of the machine operator affects accuracy of maintenance of a specified course. Currently, there are no ready-made technical products for automating the process of setting the course and controlling the movement of heading machines. This paper deals with the implementation of the navigation system for heading machines in the underground mines of Uralkali company. At the mines of Uralkali, the requirements for the accuracy of such a system are dictated by the requirements for the accuracy of mine surveying support for underground mining operations in driving new roadways. Possible ways of constructing navigation systems and the problems of their application are considered. The analysis of the existing methods shows that the most promising option for navigation of heading machines in underground mine openings are the systems based on the principles of inertial navigation. To use such systems in underground mines and to ensure the required accuracy, the technical requirements for the systems are formulated. It is shown that modern strapdown inertial navigation systems satisfy the required accuracy. On their basis, a prototype of the heading machine navigation system was developed, and its ground tests were carried out. The achieved accuracy of the system makes it possible to proceed to testing of a real heading machine in a mine. The study was supported by the Russian Science Foundation, Project No. 19-77-30008.

Determination of bench, dump and road sliding wedge technological parameters

Mine surveying in mining operations is of particular importance, since all technological processes of the full life cycle of a mining enterprise and, ultimately, its competitiveness depend on the surveying quality, efficiency and reliability. Organizations independently determine the structure of mine surveying services, taking into account the methods applied and the scale of mining. To ensure safe open-pit mining of minerals, it is necessary to permanently assess and monitor the pit bench and wall rock mass condition. Misjudgement of rock physical and mechanical properties, non-observance of the minerals mining and transportation process cycle, changes in climatic conditions and other problems lead to loss of stability of rocks in all parts of an open pit, including in the areas of ore production and mining and transport equipment operation. The existing practice shows that the effectiveness of an open pit wall and bench stability calculation can be achieved using a technique that should take into account the slope deformation and failure mechanism, as well as the nature of the stress-strain state of the open pit rock mass. The studies presented in the paper are based on comparative analysis of the sliding wedge parameters for benches, dumps and roads at open pits using analytical and graphical software packages, and taking into account the static load produced by dump trucks. The study findings allow to establish that: determination of the bench slope stability and the sliding wedge width, performed by the analytical method, gives higher accuracy results than those obtained by the graphical method; the bench slope stability and the sliding wedge width depend not only on the rock physical and mechanical condition, but also on the bench height, the dump truck (plus its freight load) weight per 1 linear meter of the placement area, the distance from the slope edge and other factors; the rock mass is stable and not subject to landslide phenomena for as long as the sum of the holding forces is greater than or equal to the sum of the shearing forces; when using large-sized transport equipment of nonstandard weight in open-pit mining, it is necessary to calculate the safe width of the sliding wedges, taking into account the loads on them (per 1 linear meter), the values of which can be 1.5–2.0 times higher than those calculated for the circular-cylindrical sliding surface.

Taking into account the spatial variability of the physical and mechanical properties of a hydraulic dump when flushing it

Introduction. Slope stability analysis reliability depends on the level of schematizing the results of engineering-geological survey, hydrogeological monitoring, electrical sounding, and mine surveying data generalization. In order to improve the stability analysis accuracy, it is relevant to use the geomechanical models, which take into account the spatial variability of the adjacent rock mass physical and mechanical properties, with further search for the most hazardous section in the plan. Research aim is to substantiate the relevance of slopes physical and mechanical monitoring by the methods of downhole control and further stability analysis with the use of the geological and geophysical models. Methodology includes the search for the most hazardous section of the rock mass by the ratio of the shearing and restraining forces within the limits of the established zones characterized by the variability of physical and mechanical properties. Results. As a result of generalizing the databases of the engineering and geological study, hydrogeological monitoring, electrical sounding and mine surveying, the volumetric geological and geophysical models were built of the technogenic massif formed at the dump, as well as the slopes of the hydraulic overburden face, represented by the three-level fill of dry overburden. Test areas stability has been analyzed for the actual position, and the comparative analysis of the results was made. Conclusions. When building volumetric geological and geophysical models of man-made rock masses formed at the areas of filled hydraulic waste diposals, in addition to the results of the traditional survey measurements and direct engineering and geological study, it is important to create informative databases on spatial and temporal variations of physical and mechanical properties of alluvial rock conditioned by their fluid loss and consolidation, which with in details at cross hole intervals may be obtained based on the statistical dependences on electrical conductive properties variation by the methods of electrical sounding or tomography; and when making enclosing embankments (bridges) of dry rocks – information about excess pore pressure under these facilities. When using the hydromechanized method for the alluvial rocks, relatively homogeneous in strength properties, the hydraulic overburden face slope stability is determined to the greatest extent by the absolute values of the accumulated strength indicators in the mined area and the unfavorable combination of the edge shape (the presence of protruding sections and face unevenness in the plan) with the entry height. The established range of the stability coefficient was n = 1.03–3.76. The stability of the enclosing structures made of dry rock to the greatest extent depends on weak alluvial layer depth and thickness and the absolute value of excess pore pressure in this layer. The established range of stability coefficient variation for this rock mass section is much narrower and amounted to n = 1.29–1.59.

Digitization of the multi-compositional Storkwitz carbonatite diatreme (Delitzsch Complex, Germany)

<p> </p><p>The Storkwitz diatreme is a multiphase composite body within the Late Cretaceous Delitzsch Complex in north-western Saxony, Germany. The lithology of the Delitzsch Complex varies from rauhaugite and fenite aureole to ultramafic and alkaline lamprophyric intrusions (dykes, sills and pipe-shaped bodies) accompanied by the formation of diatremes of variable composition (Krüger et al., 2013; Röllig et al., 1990). The final stages are represented by beforsite and alvikite dykes (Röllig et al., 1990). The multi-component nature of the Storkwitz diatreme can be attributed to the formation of polymict breccias and numerous injections of compositionally varied carbonatites (Gevorgyan et al., 2020; Seifert et al., 2000).  </p><p>The entire area was extensively explored through an intensive drilling campaign by the <em>SDAG Wismut</em> between 1972 and 1989, due to a locally increased REE content. For a better understanding of the development of the diatreme, detailed petrographical observations and new imaging methods on extensive drill core material were applied. The combination of microscopic images and high-resolution 2D-images allows to create 3D-models of drill core sections via photogrammetry. Identifying the components (xenoliths and intraclasts) and analyzing the pattern of their distribution in the 3D-models of drill cores will enable obtaining textural information of the minerals within the rocks.</p><p>Further investigations using Hyperspectral Imaging (HIS) for chemical information, to be carried out in cooperation with the <em>Institute for Mine Surveying and Geodesy, TU Bergakademie Freiberg</em>, combined with mineralogical information and 3D-models, will provide new insights into the shape and geometry of the diatreme body.</p><p> </p><p><strong>References</strong></p><p>Gevorgyan, H., Schmidt, S., Kogan, I., Lapp, M., 2020. EGU2020-10678.</p><p>Krüger, J.C., Romer, R.L., Kämpf, H., 2013. Chemical Geology, 353, 140-150.</p><p>Röllig, G., Viehweg, M., Reuter, N., 1990. Zeitschrift für Angewandte Geologie, 36, 49-54.</p><p>Seifert, W., Kämpf, H., Wasternack, J., 2000. Lithos, 53, 81-100.</p>