Ventilation Shaft Research Articles

Optimization Study of Guide Vanes for the Intake Fan-Duct Connection Using CFD

The connection between an intake fan and a ventilation shaft must be designed in such a way that it minimizes the energy waste due to singularity losses. As a result, the questions of which radius of curvature to use and if guide vanes have to be included need to be answered. In that case, the variables such as the number, upstream and downstream penetration length, radius of curvature, and width of the vanes, need to be defined. Although this work is oriented to mine ventilation, these questions are usually valid in other engineering applications as well. The objective of this study is to define the previously mentioned variables to determine the optimal design combination for the radius/diameter relationship (r/D). Computational fluid dynamics was used to determine the shock loss factor of seven elbow curvature ratios for a 3 m diameter duct and fan, with and without guide vanes to estimate the best performing configuration and, therefore, to maximize the fan airflow volume. The methodology used consisted of initially developing models in 2D geometries, to optimize the meshing and the CPU use, and studying separately the number of vanes, upstream and downstream penetration, radius of curvature, and width of the vanes for each curvature ratio (r/D). Then, the best-performing variable combinations for each curvature ratio were selected to be simulated and studied with the 3D geometries. The application of the guide vane designs for three-dimensional simulated geometries is presented, first without and then with guide vanes, including the shock loss factors obtained. The methodology and obtained results allowed quantifying the energy savings and to reduce the CFD simulations steps required to optimize the design of the elbow and guide vanes. The results obtained cannot be used with elbows in exhaust fans, because fluid dynamics phenomena are different.

Experimental study of train-induced pressure acting on the platform screen doors in subway station

The pressure transient on a platform screen door (PSD) is crucial for its structural safety and proper operation. This study experimentally investigated the train-induced pressure on the PSDs in a typical subway station using a moving model test system. Two typical cases were tested: the non-stop and chasing cases. In the non-stop case, the train passes through the station without stopping. In the chasing case, the train runs towards the station through the tunnel, while another train stops at the station. The train-induced pressure inside the tunnel was also tested for comparison. It was found that the train generated a compression wave when it passed the ventilation shaft of the tunnel, which was similar to that occurring when it entered the tunnel. In the non-stop case, the PSDs experienced two positive and one negative pressure peaks during the entire process. The first positive peak was dominated by the pressure wave transmitted through the tunnel; the second positive peak occurred when the train head reached the PSDs. A negative pressure peak occurred when the train tail passed by. In the chasing case, even when the incoming train was far away from the station, its pressure wave resulted in significant pressure on the PSDs, which may be the reason why the PSDs cannot open properly during rush hours.

Noise Control design for a Ventilation Fan - Case Study

A ventilation system was design and installed for a multi story garage. The ventilation system system had a vertical concrete shaft with the ventilation fan located on the top floor at street level. The ventilation fan is separated from the outside by a set of metal louvers. Adjacent to the louvers is an open pedestrian area. The exhaust fan as installed had an inline duct silencer but this was insufficient in terms of providing the desired noise mitigation. The project desire was not to make changes to the fan or its inline silencer or the external louvers so an alternative noise mitigation option had to be explored. Based on the provided sound power characteristics of the fan, the exterior noise levels as calculated matched the expected levels coming out of the metal louvers. The interior of the ventilation shaft is bare concrete with the fan installed though a hole in the concrete top floor. The predominate noise was the very high reverberation inside the ventilation shaft. The owner of the property made an attempt at installing noise absorption but this was not sufficient. Based on the field data the sound levels with the preliminary absorption solution matched expectation, but further noise reduction was required. A complete sound absorption on the walls of the concrete ventilation shaft noise mitigation solution was design, and the expected levels predicted to show that significant noise reductions can be obtained by a comprehensive noise absorption solution. The noise mitigation solution was implemented and exterior sound level measurements performed at the completion of the project. The measured sound levels outside of the metal louvers were in very good agreement with the predicted levels. Based on the success of this first noise mitigation solution, noise mitigation for a second ventilation system is not being considered.

The Influence of an Impedance Obstacle on the Acoustic Field Inside a Rectangular Room

Abstract The problem of sound propagation inside a rigid-walled room containing a rectangular obstacle was solved by dividing an acoustic field into subregions and using the continuity conditions. Acoustic waves were generated by a point source. The formulas valid for an impedance obstacle extending from a room floor to its ceiling were obtained. The considered obstacle can model such elements as a ventilation shaft, furniture, or construction pillar. The solution was expressed in the form of convergent series. To obtain accurate results, the error resulting from the use of truncated series was controlled. Additionally, to check the correctness of the proposed solution and its computer implementation, the results obtained for a negligibly small obstacle were compared with those given by the empty room model. An excellent agreement was achieved which proves a high accuracy of the used methodology. The numerical analysis shows that the calculation time of acoustic pressure in a part of an empty room can be significantly reduced using the obtained solution. An appropriate source location for noise reduction was found. The distribution of acoustic field was illustrated and some conclusions were formulated. The changes in acoustic field due to the presence of an obstacle were predicted and discussed.

Experimental, analytical, and computational study of natural convection in asymmetrically-heated vertical shafts

During building fires, buoyant smoke is rapidly transported through elevator and ventilation shafts, posing a threat to the safety of occupants on higher floors. Therefore, smoke dynamics in vertical shafts are of interest to fire and building safety engineers. Herein, analytical solutions describing pure natural-convection laminar flows in asymmetrically-heated vertical shafts are introduced and discussed as a model situation. While the analytical solution is limited to laminar flow at relatively low Rayleigh numbers, a practically-relevant turbulent flow is explored experimentally, with a lab-scale 1-m-high shaft, and numerically, with Fire Dynamics Simulator (FDS) software in the same scale. With supplied heating powers of 100–400 W at the left-hand side wall or/and bottom, a circulatory 2D or/and 3D heat-induced convection flow (natural convection) sets in within the shaft. Air near the heated left wall rises due to buoyancy, while air near the cooler right wall descends, yielding a sine-wave-shaped velocity profile with no-slip boundary conditions imposed at both walls. While this sine-wave velocity profile is clearly observed in laminar flow, the buoyancy-driven layers are relatively thin in the corresponding turbulent flow. The temperature profile practically linearly decreases from the left to the right wall for both laminar and turbulent flows. The overall physical insights provided by the laminar analytical solution are consistent with observations in the turbulent flow. The differences between laminar and turbulent flows are investigated and discussed by qualitatively comparing the analytical solutions to the experimental and numerical data.

MOVEMENT ALGORITHM OF AN AUTONOMOUS ROBOT-HEXAPOD FOR MOVING IN NARROW CLOSED SPACES

The article proposes the use of a walking robot - hexapod for its use to monitor the technical condition of ventilation shafts, technical dry channels, enclosed spaces, etc. The peculiarity of this type of robots is the increased possibility in comparison with tracked or wheeled machines, due to their design and ability to overcome irregularities. Also, in comparison with existing designs, the hexapod can be fully autonomous and does not depend on a stationary power source. In its turn, construction of walking robots requires development of complex algorithms of motion, which are significantly different compared to wheeled or tracked moving devices, because in addition to the control of limbs, which are set in motion by servo drives, the computer core must process information from sensors that provide information both about the position of the robot itself, and about the surrounding objects, which can be: distance sensors, touch sensors, video cameras, accelerometers, gyroscopes, etc.
 The paper highlights the developments used to date, but analysis of existing algorithms for walking robots showed a lack of such for the use of the robot in narrow and confined spaces, ventilation shafts, dry technical ducts, etc. In this regard, an algorithm was developed that partially closes this gap. The peculiarity of this algorithm is the simplicity of practical implementation, as well as the safety of the construction of work in progress, because it takes into account the need for increased static stability by modifying the matrix of limb position by a third state, which gives the opportunity to consider the initial position, or memorize the limb state, from which, in the future, you can continue the movement from an arbitrary stable position. In addition, the algorithm can be applied not only to robots with six limbs, but also to other kinds of mobile walking platforms, because the proposed variant allows testing and calibration of any type of gait at each iteration of the step.
 In the future, it is planned to test the proposed algorithm on the developed prototype not only when moving the work on horizontal surfaces, but also on vertical surfaces, which is an important component for the proposed application area.

Study on large deformation mechanism and concrete-filled steel tubular support technology for ventilation shaft roadway

Study on large deformation mechanism and concrete-filled steel tubular support technology for ventilation shaft roadway

TO THE QUESTION OF INSPECTION AND EXAMINATION OF SOFT ROOFS

Problem statement. The discrepancy between the requirements for soft roofs and their actual condition is gradually increasing, especially in conditions of significant restrictions on the funds allocated for their maintenance and repair. Under these conditions, organizations repairing and restoring roofs reimburse the cost of repairing or installing new ones using lower quality materials, reducing the number of layers of both the main roll carpet, which is laid, and the details of combining the roof with protruding elements on the floor (parapets, lanterns). structures, ventilation shafts, etc.). From these positions, the generalization of the experience of examinations and the improvement of the methodology for verifying the effectiveness of the use of funds provided for the installation or repair of roofs, is a very important task today. Purpose of the article. Recommendations for improving the quality of examinations performed on the inspection of commissioned soft roofs, and the procedure for determining whether they comply with the requirements of current regulatory and technical documentation. Conclusion. Determining the quality and checking the effectiveness of the use of funds provided for the construction, reconstruction and repair of soft roofs in our country in order to improve their condition at the moment is still a very important issue. The training of specialists in matters related to the repair and operation of roofs at the current level has shortcomings. The current regulatory and technical documentation in the field of repair, reconstruction and operation of modern roofs does not contain sufficient information, taking into account modern technologies of their device. For qualitative, operative and objective assessment of quality of inspected soft roofs and definition of cost of volumes, actually executed works on construction, reconstruction and repair it is necessary to equip all interested participants with the modern devices allowing to improve quality of performed examinations considerably.

Combined benefits of cooling with heat recovery for electrical cable tunnels in cities

Electrical power in cities is typically distributed by means of underground cable tunnels. The cables generate significant heat, and tunnel temperature is generally controlled via ventilation shafts with circulation to prevent overheating. If active cooling of the inlet air is provided, then temperatures can be lowered and electrical distribution losses reduced. This novel study, the first looking at cable tunnels with District Heating, investigates the effect and impact of heat recovery. The work combines technical and economic modelling together with measured data from a case study and shows significant benefits with wide-scale replication potential.A finite element (FE) model, for heat dissipation in a section of cable tunnel together with a spreadsheet model has shown that up to 460 kW of heat can be delivered to the local heating network for a single cooling point. The study indicates savings of 570 kg CO2e and 4000 kWh (of combined heat and electrical energy) per metre of tunnel per annum with reduced operating costs. Given the widespread network of cable and other tunnels in major cities, close to numerous heat users, the application of these techniques has major financial and low-carbon benefits for the UK and globally.

Method of Selecting the Means of Transport of the Winning, Taking into Account Environmental Aspects

The transport of the winning in deep mines, using the room and pillar mining system, is most often performed with bucket loaders and haul trucks. In the era of attempts to stop rapid climate change, it is crucial to choose the transport means for the winning both in terms of efficiency and cost-effectiveness and to consider its environmental aspect. Permissible levels of pollutant emissions in exhaust gases are defined for this type of means of transport by the EU Stage Standards. There is a discernible need to develop a multi-criteria method supporting the decision-making process, which should reward loaders and haul trucks that meet more stringent emission standards. The article proposes an innovative idea of taking environmental aspects into account when selecting loaders and haul trucks for excavated material transport tasks, so that the amount of pollutants emitted by them in exhaust gases, e.g., the sum of hydrocarbons and nitrogen oxides (HC+NOx), is also taken into consideration when assigning means of transport to particular tasks. Based on simulation studies for a specific case, it was found that a 20% reduction of HC+NOx emission is possible with only a 2% increase in the transport costs of the winning. For this purpose, an objective function was used formulated on the basis of two criteria: minimization of the transport cost of the winning and the level of pollutant emissions in the exhaust gases. Since dozens of mining machines are operated continuously in deep mines of non-ferrous metal ores, the application of the proposed method would significantly reduce the emission of pollutants in the used air coming out of ventilation shafts.

Estimating Upper Silesian coal mine methane emissions from airborne in situ observations and dispersion modeling

Abstract. Abundant mining and industrial activities located in the Upper Silesian Coal Basin (USCB) lead to large emissions of the potent greenhouse gas (GHG) methane (CH4). The strong localization of CH4 emitters (mostly confined to known coal mine ventilation shafts) and the large emissions of 448 and 720 kt CH4 yr−1 reported in the European Pollutant Release and Transfer Register (E-PRTR 2017) and the Emissions Database for Global Atmospheric Research (EDGAR v4.3.2), respectively, make the USCB a prime research target for validating and improving CH4 flux estimation techniques. High-precision observations of this GHG were made downwind of local (e.g., single facilities) to regional-scale (e.g., agglomerations) sources in the context of the CoMet 1.0 campaign in early summer 2018. A quantum cascade–interband cascade laser (QCL–ICL)-based spectrometer adapted for airborne research was deployed aboard the German Aerospace Center (DLR) Cessna 208B to sample the planetary boundary layer (PBL) in situ. Regional CH4 emission estimates for the USCB are derived using a model approach including assimilated wind soundings from three ground-based Doppler lidars. Although retrieving estimates for individual emitters is difficult using only single flights due to sparse data availability, the combination of two flights allows for exploiting different meteorological conditions (analogous to a sparse tomography algorithm) to establish confidence on facility-level estimates. Emission rates from individual sources not only are needed for unambiguous comparisons between bottom-up and top-down inventories but also become indispensable if (independently verifiable) sanctions are to be imposed on individual companies emitting GHGs. An uncertainty analysis is presented for both the regional-scale and facility-level emission estimates. We find instantaneous coal mine emission estimates of 451/423 ± 77/79 kt CH4 yr−1 for the morning/afternoon flight of 6 June 2018. The derived fuel-exploitation emission rates coincide (±6 %) with annual-average inventorial data from E-PRTR 2017 although they are distinctly lower (−28 %/−32 %) than values reported in EDGAR v4.3.2. Discrepancies in available emission inventories could potentially be narrowed down with sufficient observations using the method described herein to bridge the gap between instantaneous emission estimates and yearly averaged inventories.

Experimental studies on the smoke extraction performance by different types of ventilation shafts in extra-long road tunnel fires

Ventilation shafts are widely applied in extra-long road tunnels. Experiments were conducted in a 1/20 scale model tunnel to investigate the smoke extraction performance with a ventilation shaft. Four types of shafts were compared under the normal ventilation mode and the smoke extraction mode. The influence of shaft types, the operation frequency of the jet fan and board locations were investigated. Results indicate that the smoke extraction capacity of the mechanical ventilation shaft (MTS) is almost the same as the operation frequency increases, but the smoke extraction efficiency declines as the operation frequency increases. Besides, it can be found that the smoke extraction capacity and the smoke extraction efficiency of the mechanical board-coupled shaft (MBCS) decrease as the operation frequency increases. Moreover, it was found that the smoke extraction performance of the MBCS is highly affected by the distance between the board and the shaft. And the optimal board location for the MBCS changes with the operation frequency. Furthermore, the coupling-effect of the momentum induced by the mechanical ventilation and the buoyancy induced by the hot smoke in the ventilation shaft during a fire was explored. And the dimensionless smoke extraction Froude number (Frs), was developed for characterizing the buoyancy-momentum transition during the smoke extraction process with the mechanical ventilation shaft. These studies may contribute positive significance in the smoke control and extraction design with extra-long road tunnels.

Airborne Spread of Methicillin Resistant Staphylococcus aureus From a Swine Farm.

Spread of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) to farmworkers has been recognized as a risk when working in LA-MRSA positive stables, due to LA-MRSA being present on airborne dust particles. Based on this, airborne spread of LA-MRSA through stable vents is a concern that is addressed in this study. The aim of the investigation was to quantify the airborne spread of LA-MRSA from a MRSA positive swine farm. In order to achieve this, a method for sampling large volumes of air was applied. The results were compared to meteorological data and bacteriological investigation of samples from the air inside the swine barn, soil outside the farm, and nasal samples from the individuals participating in the sampling process. MRSA was detected up to 300 m (the maximal measuring distance) from the swine farm in the air but only at low levels at distances above 50 meters (0.085 CFU/m3 at a distance of 50 m in the wind plume). MRSA was detected in sock samples obtained at the soil surfaces up to 400 m (the maximal measuring distance) from the farm building. The proportion of MRSA positive soil samples decreased from ~80 to 30% with increasing distance from the farm. A total of 25 human nasal samples were sampled after the farm visits after the participants had stayed in the surroundings of the farm for an average of 10.5 h. When leaving the farm, only two of the samples (8%) were LA-MRSA-positive both obtained from one individual who was the one who had sampled the ventilation shafts. In conclusion, airborne spread of MRSA from swine farms does not seem to be an important route for human contamination for individuals staying a whole working day outside a swine farm.

Study of Heat and Mass Transfer in Ventilation Shafts of Deep Mines in the Case of Airflow Reverse

This article presents the results of a simulation of conjugate heat transfer between cold air and warm shaft lining during airflow reverse at a hard rock mine. A comparison of the numerical results with collected experimental data was carried out. A significant discrepancy between the two was revealed, indicating that not all heat sources and additional air heating mechanisms were taken into account in the simulation. Possible reasons for the discrepancy are discussed and the most probable reasons are identified for further study. A quantitative assessment of the possible factors considered is carried out. Further tasks for research are determined.

Mindlin-Reissner Analytical Model with Curvature for Tunnel Ventilation Shafts Analysis

The formulation and analytic solution of a new mathematical model with constitutive curvature for analysis of tunnel ventilation shaft wall is proposed. Based on the Mindlin–Reissner theory for thick shells, this model also takes into account the shell constitutive curvature and considers an expression of the shear correction factor variable (αn) in terms of the thickness (h) and the radius of curvature (R). The main advantage of the proposed model is that it has the possibility to analyze thin, medium and thick tunnel ventilation shafts. As a result, two comparisons were made: the first one, between the new model and the Mindlin–Reissner model without constitutive curvature with the shear correction factor αn=5/6 as a constant, and the other, between the new model and the tridimensional numerical models (solids and shells) obtained by finite element method for different slenderness ratios (h/R). The limitation of the proposed model is that it is to be formulated for a general linear-elastic and axial-symmetrical state with continuous distribution of the mass.

Expanding the FDS Simulation Capabilities to Fire Tunnel Scenarios Through a Novel Multi-scale Model

Computational Fluid Dynamics (CFD) is widely used to simulate tunnels and partially substitute on-site tests. As technology advances, new application opportunities appear; some examples are the optimal operation of ventilation and emergency systems, risk assessment of tunnels and training of the operators. Even when the computational capacity of computers has grown, CFD is still constrained by the large amount of computational resources needed in long tunnels. This introduces a need for methods able to reduce the amount of time required for simulations. To face this need, a novel 1D–3D multiscale model is presented in this paper. The model incorporates the code Whitesmoke into FDS (Fire Dynamics Simulator) through a direct coupling. Whitesmoke manages the fluid dynamics, temperature and concentration of species in the 1D portion, while FDS calculates these fields in the portion where fire occurs. Using this multiscale model, the computation time for long tunnels is reduced, proportionally to the 1D length in the domain. Also, additional simulation capabilities particularly useful for tunnel analysis are obtained. Some new characteristics are pressure boundary conditions can be easily imposed at the tunnel portals or at the ventilation shafts; the characteristic curves of the fans/jet-fans can be included, also considering the degradation effects due to smoke propagation; the piston effect can be properly considered. Our research verifies most of its capabilities, also clarifying its limitations and the criteria used to set the domain for the analysis. As a final step, the model is tested in a tunnel with a cross section of 4.8 m and 600 m of length with a 2 MW fire, comparing its performance with a full 3D FDS simulation. The difference in temperature and velocity is minimal for most of the domain, making It a good way to optimize resource usage in large simulations. Furthermore, the multiscale manages to reduce the computational time of more than a 50%.

Rare Occurrence of Mirabilite in the Thirteenth-Century Historic Salt Mine in Bochnia (Poland): Characterisation, Preservation, and Geotourism

The small stalactites found on the ceiling at level I near the Sutoris shaft in the thirteenth-century historic salt mine in Bochnia, Poland, are mainly composed of mirabilite (Na2SO4·10H2O) followed by blödite (Na2Mg(SO4)2·4H2O). The unique presence of these two minerals in only one location in this old underground mine is attributed to contemporary precipitation from percolating solutions. This can be caused by a combination of at least two factors: a specific and stable microclimate (characterised by a low temperature, high humidity, and relatively strong air circulation which accelerates the processes of evaporation and crystallisation) and the specific chemical composition of the leaking solution (contains a low carbonate and high sulphate content, and characterised by acidic pH (4.8) and intermediate-mineralisation (174,308 mg/L)). The microclimate specified above can be linked to the long distance from the ventilation shaft that pumps the air from the surface to the mine, while the composition of the leaking solution as well as the hydrochemical modelling results obtained with PHREEQC can be directly related to the top anhydrite layer and the overlying secondary cap consisting mainly of claystone, anhydrite, and gypsum. In this study, the challenges underlying the preservation of mirabilite in the underground environment of the salt mine are discussed, in terms of both nature and mining law. Based on the results of detailed geological, mineralogical, and chemical research, appropriate solutions that can be practically applied for the management, preservation, and protection of the mirabilite efflorescence are proposed. The presence of this intriguing mineral, with appropriate protection, can be another geological attraction for tourists visiting this thirteenth-century UNESCO-recognised salt mine.

Detection and quantification of CH<sub>4</sub> plumes using the WFM-DOAS retrieval on AVIRIS-NG hyperspectral data

Abstract. Methane is the second most important anthropogenic greenhouse gas in the Earth's atmosphere. To effectively reduce these emissions, a good knowledge of source locations and strengths is required. Airborne remote sensing instruments such as the Airborne Visible InfraRed Imaging Spectrometer – Next Generation (AVIRIS-NG) with meter-scale imaging capabilities are able to yield information about the locations and magnitudes of methane sources. In this study, we successfully applied the weighting function modified differential optical absorption spectroscopy (WFM-DOAS) algorithm to AVIRIS-NG data measured in Canada and the Four Corners region. The WFM-DOAS retrieval is conceptually located between the statistical matched filter (MF) and the optimal-estimation-based iterative maximum a posteriori DOAS (IMAP-DOAS) retrieval algorithm, both of which were already applied successfully to AVIRIS-NG data. The WFM-DOAS algorithm is based on a first order Taylor series approximation of the Lambert–Beer law using only one precalculated radiative transfer calculation per scene. This yields the fast quantitative processing of large data sets. We detected several methane plumes in the AVIRIS-NG images recorded during the Arctic-Boreal Vulnerability Experiment (ABoVE) Airborne Campaign and successfully retrieved a coal mine ventilation shaft plume observed during the Four Corners measurement campaign. The comparison between IMAP-DOAS, MF, and WFM-DOAS showed good agreement for the coal mine ventilation shaft plume. An additional comparison between MF and WFM-DOAS for a subset of plumes showed good agreement for one plume and some differences for the others. For five plumes, the emissions were estimated using a simple cross-sectional flux method. The retrieved fluxes originated from well pads, cold vents, and a coal mine ventilation shaft and ranged between (155 ± 71) kg (CH4) h−1 and (1220 ± 450) kg (CH4) h−1. The wind velocity was a significant source of uncertainty in all plumes, followed by the single pixel retrieval noise and the uncertainty due to atmospheric variability. The noise of the retrieved CH4 imagery over bright surfaces (>1 µW cm−2 nm−1 sr−1 at 2140 nm) was typically ±2.3 % of the background total column of CH4 when fitting strong absorption lines around 2300 nm but could reach over ±5 % for darker surfaces (< 0.3 µW cm−2 nm−1 sr−1 at 2140 nm). Additionally, a worst case large-scale bias due to the assumptions made in the WFM-DOAS retrieval was estimated to be ±5.4 %. Radiance and fit quality filters were implemented to exclude the most uncertain results from further analysis mostly due to either dark surfaces or surfaces where the surface spectral reflection structures are similar to CH4 absorption features at the spectral resolution of the AVIRIS-NG instrument.

BIM-based ventilation shaft construction schedule simulation and plan optimization

In order to solve the problems of multiple construction links, mutual influence and restriction, and tight construction period of the ventilation shaft under complex geological conditions, the BIM technology is used to realize the three-dimensional parametric modeling of the Nanhu ventilation shaft project from geology, main structure and main construction equipment, etc. Simulating the construction schedule, formulating a reasonable schedule and optimizing the construction plan are of great significance for accelerating the construction schedule, controlling construction risks, and striving to make the Nanhu air shaft project put into use as soon as possible.

Geomechanical characteristic of ventilation shaft VS-3 in Oktyabrsky mine during extraction of mineral reserves from protective pillar

The strain analysis procedure is discussed in terms of a vertical mine shaft under the impact of extraction of ore reserves from protective pillar in Oktyabrsky mine of NorNickel’s Polar Division. The procedure is used in predictive strain analysis in depth of the shaft in case of different scenarios of protective pillar mining in ventilation shaft No. 3. The calculations show impossibility of preservation of shaft VS-3. Based on the prediction, it was decided on the early analysis of ventilation alternatives in the mine without involvement of shaft VS-3. The implemented research saved significant assets from spending on the shaft maintenance in the period of extraction of ore reserves from the protective pillar. Moreover, the time allowance until disability of shaft VS-3 enables scheduled planning and construction of access gateways to ensure the required ventilation mode in the mine. The authors appreciate participation of D. A. Kotikov, S. Yu. Shilenko, V. V. Balandin, M. P. Sergunin, A. V. Kulov, V. N. Andreev and A. K. Ustinov in the study.