Reducing the Risk of Mud Rushes in Sokolov Iron Mine

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Rybnikov, Evgenii Y. Efremov This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4808030/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Mud rushes from the caved rock zone pose a danger to mining operations. Large ore deposits that are mined using sublevel caving systems are susceptible to this problem. The difficult hydrogeological conditions of the Sokolov iron ore deposit (Sokolov-Sarbay ore zone, Republic of Kazakhstan) necessitated the construction of a complex drainage system consisting of an external drainage gallery around the deposit that intercepts the main flux from the Cretaceous aquifer, and internal drainage facilities, which drain all aquifers within the caved rock zone. Despite the relatively effective operation of the drainage system, mud rushes of large volumes of water from the caved rock zone occur periodically. The most significant and dramatic event was the accident in 2005, which claimed two human lives and resulted in the flooding of 24 km of mine workings. It took six months to restore the mine. Smaller-scale accidents also cause significant damage since mud rushes and mud pushes lead to considerable downtimes and ore dillution, as a result of which mine productivity is significantly reduced. The paper considers the groundwater flow model of the Sokolov-Sarbay iron ore zone. Using scenario modeling, the study establishes the relationship between the hydraulic conductivity of the caved rock zone of the caved rock zone and mine water inflow into haulage level of the Sokolov underground mine. A forecast of mine water inflow is made, and mine drainage upgrading options are proposed for the purpose of improving mining safety and preventing mud rushes. Mudrush mud rush modflow groundwater modelling aquifer mining drainage Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Introduction The combination of geological structural features and mining engineering factors during mineral excavations can lead to the emergence of complicated hydrogeological conditions that pose a threat to the environment and mining operations. A common consequence of ground disturbance is mine water inflow and mud rush into underground mines (Butcher, Stacey, & Joughin, 2005). Modern practice of underground mining for copper, iron, and diamonds in steeply dipping thick ore bodies using sublevel and block caving systems leads to the formation of extensive caved rock zones. These appear on the earth's surface in the form of conical depressions and sinkholes ranging from hundreds to thousands of square meters. Sinkholes disrupt the base of all overlying aquifers, resulting in the formation of new artificial aquifer complexes, which is a source of danger for mining operations. Mud rushes from the caved rock zone amount to tens and hundreds of thousands of cubic meters. They render unusable kilometers of mine workings, cause millions of tons of minerals to be lost, and threaten human lives. The problem of mud rushes was first described with reference to the Kimberlite-hosted diamond deposits in South Africa. The first accident was recorded in 1894 (Sutton 1897). Such accidents have repeatedly led to human casualties. Thus, for example, from 1947 to 1953 there were six accidents at De Beers mines, each killing between 10 to 27 people (Kuttner and Stewart 1953). The problem of mud rushes is characterized as a specific threat characteristic of kimberlite diamond deposits. One of the most recent accidents occurred in 2011 at the Dutoitspan diamond mine, where over 4,000 m3 of mud entered the mine workings (Holder et al. 2013). In the second half of the 20th century, the problem of mud rushes was encountered during the development of iron ore deposits in the Krivoy Rog basin (USSR, Ukraine), where losses of clean and diluted ores total exceeded 550 million tons (Dubinin et al. 1989) Mud rushes are also typical for large copper deposits developed using block caving mining methods, the example being El Teniente, Chile. Over the period of 2001 to 2017, in just one of the sectors (Diablo Regimiento) of El Teniente mine, there were 94 in-rushes of wet muck and 282 in-rushes of non-wet muck recorded (Castro et al. 2017, 2018; Szczepiński 2019; Salas et al. 2022). Also known are accidents at the IOZ and DOZ mines of Block Cave Mine, PT Freeport Indonesia, where during mining, several dozens of major and minor accidents occurred due to mud rushes into the mine workings (Syaifullah et al. 2006; Rubio et al. 2011; Wicaksono et al. 2012; Setyadi et al. 2013; Cahyadi et al. 2017). At the Sokolov iron ore mine (Republic of Kazakhstan), more than 250 accidents occurred between 2004 and 2018 due to mud rushes from the stopes. The largest accident occurred in 2005, when more than 150,000 m3 of water and 35,000 m3 of mixed sedimentary rock entered the mine workings to a depth of 400–600 m with two human fatalities. More than 24,000 meters of mine workings were flooded with a mixture of water and clay. It took more than six months to restore the mine's functionality (Efremov 2019). Study area Sokolov iron ore deposit is located in the north of the Republic of Kazakhstan (Fig. 1) as a part of the Kostanay iron ore basin, one of the largest in Eurasia (contains 85% of the Republic’s iron ore reserves). The Sokolov deposit together with the Sarbay deposit located six kilometers from it form the Sokolov-Sarbay iron ore complex. Both deposits belong to the skarn type and have a similar structure; long-term drainage has resulted in a consolidated cone of depression with a radius of 10 km. Geological structure of the study area The elevations of the earth's surface in the area of the deposit are at 180–190 m. Two km south of the deposit is the river Tobol, in which water levels vary from 125 to 140 m. The deposit is located in Paleozoic metamorphic rocks, overlain by Meso-Cenozoic sediments. The latter contain a water-rich Cretaceous aquifer. The ore bodies are located at depths from 120 to 1600 m and below and dip at angle of 45 degrees. Sedimentary rocks of about 120 m in thickness occur in the upper part of the geological structure. The bedding of the rocks of different age and genesis forms several aquifers, separated from each other by impermeable layers. The following elements are distinguished in the hydrogeological section (Fig. 2): 1. The aquifer of Quaternary alluvial deposits does not feature continuous distribution. Its structure is determined by individual lens-shaped bodies of sand, sandy loam, and loam. The recharge is by infiltration, mainly due to snowmelt water. 2. The Oligocene aquifer is distributed throughout except in river valleys. It is composed of 2–8 m thick layers of sand and is characterized by a hydraulic conductivity of up to 5 m/day. The recharge is by infiltration. 3. The Chegan clay layer, which is the regional aquitard, is distributed throughout with the exception of river valleys. Its thickness is up to 35 m 4. The Eocene aquifer is composed of gaizes of the Tasarak formation to a thickness of 45 m. In its natural state, the aquifer is under pressure, with the absolute elevation of the groundwater level at about 165 m. The hydraulic properties of the aquifer are generally quite low, with the conductivity at 0.01–2.0 m/day and most commonly at 0.3–0.6 m/day. The recharge of the aquifer is through the area where it reaches the surface, as well as by flow-over from the Cretaceous sands. 5. The Cretaceous aquifer is composed of quartz-mica and quartz-glauconitic sands. The aquifer spreads throughout and rests on the lignite clays and rubble-loam deposits of the weathering crust. The aquifer is confined; under natural conditions, the groundwater level is at 165 m. The thickness of the aquifer in the area of the deposit reaches 50 m. The hydraulic conductivity of the Cretaceous sands decreases from 20 m/day in the river valleys to 0.05 m/day towards the watershed (Edigenov 2013). The aquifer is recharged at sites where the regional aquitard has eroded. In the areas of the Sokolov and Sarbay deposits, there is no layer of Maastrichtian clays; therefore, the Eocene and Cretaceous aquifers are considered as a single Eocene-Cretaceous complex. This complex is the main source of water encroachment for the mine workings. 6. The weathering crust consists of lignite clays in thicknesses varying significantly from zero to dozens of meters, and up to 150 m in fault areas. The weathering crust presents a relative aquitard; the connection between the Cretaceous aquifer and the underlying aquifer complex is through hydrogeological windows at places where sands rest on the Paleozoic foundation. 7. The Paleozoic aquifer complex extends throughout and includes several stratigraphic divisions of the Silurian, Devonian, and Carboniferous. The rocks of the Paleozoic complex are represented by an effusive-sedimentary sequence composed of andesitic and basaltic porphyrites, their tuffs and tuff breccias, and less commonly, by limestones and tuffites of the Lower Carboniferous. The rocks feature diorite and diabase-porphyrite intrusions. Mineralization and formation of metasomatic rocks is confined to where effusive-sedimentary and intrusive rocks occur in contact. Groundwater is confined to the upper fractured zone, where open fracturing is developed to a depth of 20–40 m; in effusive sedimentary rocks and in zones of tectonic disturbances, it reaches a depth of 100 m or more (Veselov et al. 1992). The hydraulic conductivity of the rocks varies with depth, being 0.085 m/day in the upper part and decreasing to 0.0005 m/day in the middle. Effects of Mining Mining at the Sokolov deposit is carried out using a combined method: the larger southern part is developed by the open-pit mining, while the northern part by underground mining. The Sarbay deposit is developed by the open-pit. The northern part of the Sokolov deposit is mined using sublevel mining method. The shafts are located in the west in the basewall of the deposit. Ore bodies are accessed at 5 horizons at levels -60 m, -120 m, 190 m, -260 m, -330 m, and -400 m. At the moment, stoping is conducted mainly at the -330 m complex. Thus, the current depth of operations is about 500 m (Исанченко , Верин, & Раков, 2004). From 1976 to 1998, the deposit was mined with the filling of the goaf. The caved rock zone began forming in 1981. In total, more than 100 craters emerged to the surface, many of which re-emerged in already formed craters. Currently, the caved rock zone on the surface measures about 1600 m in length and 600 m in width, oriented submeridionally (Fig. 3). The caved rock zone consists of four groups of individual pipe-shaped cones, and its shape is determined by the configuration of the ore bodies. To prevent the accumulation of water in open craters, since 2009 they are being filled with waste rock from the Sokolov open pit. As a result of mining the steeply dipping ore bodies, caved sedimentary material (sands, loams and clays, repeatedly mixed with each other and with rock) now is found below the main aquifer (Fig. 4). The presence of a large volume of mud in the caved rock zone and the influx from the Cretaceous aquifer lead to mud rushes and to mud pushing onto the haulage levels. Mud in mine workings presents a hazard to operations, leads to production delays, ore contamination, and decreasing productivity. An analysis of 250 events showed that the volume of mud rush varies from 1 m 3 to 37,000 m 3 . Most of the large (over 100 m 3 ) wet mud rushes are localized in ore blocks located in the central and northern district of the mine field (Fig. 5) (Efremov, 2019). According to monitoring data, the main source of influx to the caved rock zone is the Cretaceous aquifer, which provides 70% of the mine water inflow; another 15% of mine water inflow is from the Paleozoic aquifer complex, hydraulically connected to the Cretaceous. The remaining 15% of the mine water inflow is from the Oligocene aquifer. To ensure the drainage of the Cretaceous aquifer, the Sokolov mine and the Sokolov open pit are surrounded along the perimeter by an integral external drainage gallery at elevation +33 m. The drainage gallery consists of underground workings driven through Paleozoic rocks and is equipped with drainholes from drainage gallery and drainholes from surface to gallery to ensure drainage of the Cretaceous aquifer. In total, the perimeter of the workings surrounding the mine is 9.5 km long, and that around the open pit is 15 km. Over the lifetime of the external drainage gallery, Sokolov mine has been provided with 1,222 wells drilled from drainage gallery and 100 wells drilled from the surface to the drainage gallery. To date, the Cretaceous aquifer has not yet been completely drained; the thickness of the residual water head in the vicinity of the caved rock zone is 5–20 m. In support of the efforts to increase the efficiency of the dewatering system, we have developed a groundwater model of the mining area exposed to hydrodynamic impacts. Methods and materials Data For constructing the model, use was made of cartographic materials, mining plans, geological sampling data, open-pit and underground mine drainage monitoring results, and observations of groundwater levels. Methods The groundwater conditions was simulated using MODFLOW with the Modelmuse interface, which is widely used for groundwater modeling (Harbaugh 2005), for predicting mine water inflow(Anderson et al. 2015; Szczepiński 2019; Shi et al. 2019; Maroney et al. 2022), and for karst aquifer modeling (Duran and Gill 2021). At the first stage, to calibrate the model, a series of inverse problems (in stationary formulation) were solved to reproduce the current hydrodynamic situation. At the second stage, a series of computational experiments were carried out to identify the dependence of mine water inflow on geofiltration parameters, primarily on the hydraulic conductivity of the caved rock zone, which cannot be determined using traditional methods. At the third stage, predictive scenario modeling was performed to assess the operating efficiency of the drainage facilities being designed. Model stratification The modeling area includes the Sokolov underground mine, and the Sokolov and Sarbay open pits. On the south, the area is delimited by the valley of the river Tobol (Fig. 6). In plan, the elements of the finite-difference grid have a square shape with a side of 200 m; the height of the model blocks corresponds to the thickness of the simulated layers. In the immediate vicinity of the area under study, the computational grid was refined to more accurately take into account the relief of the Cretaceous aquifer. The size of the refined grid’s cell is 50 m. The presence of a layer of Chegan clays up to 35 m in thickness, which is a regional aquitard, accounts for the separation of the regimes of the Eocene-Cretaceous complex and the Oligocene aquifer. Under natural conditions, groundwater levels differed from each other by no more than 10–20 m. As a result of mine drainage, the groundwater level of the Cretaceous aquifer decreased from 165 to 95 m, while that of the Oligocene aquifer remained almost unchanged and is still at 175 m. The absence of a hydraulic connection between the Oligocene and underlying horizons, as well as the subordinate role of the Oligocene aquifer in the total water inflow, allows it to be disregarded in the model. Thus, the model includes the Eocene-Cretaceous and Paleozoic aquifer complexes, separated by the impermeable layer of the weathering crust (Fig. 7). Since the conductivity properties of the Paleozoic rocks feature a clearly defined vertical zoning, the complex is represented by two model layers: the upper one (layer 3) corresponds to the zone of highly fractured rocks; the second, underlying one (layer 4), corresponds to a less disturbed zone (Fig. 7). The caved rock zone is considered as a separate hydrogeological element with its own conductivity and storativity parameters, which were determined through numerical experiments. Boundary conditions The relationship between heads and outflow rates was simulated using boundary conditions of the third kind (Fig. 6). The outer boundaries of the model were considered as General Head Boundary (GHB); the values of the water head are set at a distance (through corresponding filtration resistance) such that enables one to reproduce the formation of a cone of depression in the course of aquifer drainage. The river Tobol was modeled with the help of the River package (RIV); the parameters of bottom sediment resistance were determined during the calibration of the model. Groundwater inflow to mine workings was modeled using the Drain package (DRN). The depths of the drains correspond to the following elevations: for the external drainage complex of the Sokolov underground mine – to the elevations of the Cretaceous aquifer’s base; for the caved rock zone – to the stoping depth; and for the open pits – to the elevations of the side drainages. Drain resistance parameters were selected during model calibration by solving inverse problems using observational data on mine drainage. Results Calibration The invariable parameters of the model were the morphology and conductivity of the layers, the geometric elements of the model and computational grid, and the position of the main waterflows. In the course of modeling, we refined the parameters of the boundary conditions and the conductivity properties of the caved rock zone for the Sokolov mine. The criteria for calibration of model were the matching of model and observation average annual mine water inflow and groundwater levels near the ore field of the Sokolov mine (Fig. 8 ). The deviation of model inflows to drainages from observed ones did not exceed 3%. The residuals of model groundwater levels near the caved rock zone was ≤ 1 meter. Outflow from model caused underground mine and open pits (49,500 m 3 /hour) is formed due to the inflow to model from the valley of the river Tobol (40%) and inflows from the external borders from the recharge areas of the aquifer complexes in the west, north and east (60%). The levels in the Cretaceous aquifer vary from 150 m in the east to 90 m near the mine and open pits. Drainage from the Sokolov and Sarbay deposits across most of the area has led to the formation of a common cone of depression, but there is a watershed between them with a groundwater level of about 100 m. Analysis of the effect of caved rock zone conductivity on mine water inflow Since it was difficult to define the conductivity properties of rocks in the caved rock zone directly, analysis of caved rock zone conductivity have done as numerical experiment. The range of variation in the conductivity of the caved rock zone K cz was taken to be from 0.125 to 15 m/day (Fig. 9 ). The hydraulic conductivity of the Cretaceous aquifer in the area of the mine field can be considered as reliably determined at K K =2 m/day. Increasing or decreasing (almost by an order of magnitude) the hydraulic conductivity of the caved rock zone did not lead to any change in minewater inflow. A significant decrease in inflow to the drainage system occurred only for a more significant decrease in the conductivity of the caved rock zone (< 0.2 m/day). Accordingly, the main factor determining mine water inflow is the hydraulic conductivity properties of the Cretaceous aquifer. Forecasting simulation Currently, the groundwater level of the Cretaceous aquifer in the Sokolov mine ore field varies from 90 to 100 m, with an average of 95 m (Fig. 8 ). The morphology of the aquifer base is complex: there are numerous hills and depressions, with the elevation range of 30 m (Fig. 10 ). Along the perimeter of the caved rock zone, the saturated thickness is 5–15 m, which means that the inflow from the Cretaceous aquifer persists. Despite operating drainage, the inflow of water to the caved rock zone occurs through saddle-shaped depressions between local elevations. To disrupt the hydraulic connection between the Cretaceous aquifer and the caved rock zone, it is necessary to reduce groundwater levels to the level of the aquifer base. Based on this consideration, the groundwater level at the border with the caved rock zone should not exceed 82 m. This will create conditions for groundwater drawdown in caved rock zone, the volume of which now amounts to 4.3 million m 3 , and prevent mud rushes. Predictive modeling assumed the following starting points: 1. The target is to reduce the groundwater level in the Cretaceous aquifer near the caved rock zone to the elevation 82 m. 2. Drawdown is carried out using six wells (in addition to the existing drainage gallery) with a flow rate of 50 m 3 /hour (1200 m 3 /day) each. The wells are located in local depressions in the relief of the Cretaceous aquifer base and are modeled using specified flux boundary conditions. 3. The rate of drawdown at the geometric center of the caved rock zone is determined. Since it is impossible to determine reliably the specific storage of caved rock zone, scenario modeling was used depending on specific storage values for the caved rock zone scenario 1 = the specific storage of the caved rock zone has increased as a result of deconsolidation; scenario 2 = the specific storage of the caved rock zone is equal to that of the main aquifer; scenario 3 = the specific storage of the caved rock zone has decreased due to gravitational compression (redeposition) (Table 1 ). The specific storage values of the weathering crust and the Paleozoic aquifer remained constant for all three scenarios. Table 1 Groundwater model parameters Element of model k, m/day Specific storage (S s ) for scenario, m − 1 1 2 3 Cretaceous aquifer 2 1*10 − 4 1*10 − 4 1*10 − 5 Caved rock zone 10 1*10 − 4 1*10 − 5 1*10 − 6 Weathering crust of Paleozoic rocks 0,0005 1*10 − 6 1*10 − 6 1*10 − 6 Upper part of the fractured zone of the Paleozoic aquifer complex 0,085 1*10 − 6 1*10 − 6 1*10 − 6 Lower part of the fractured zone of the Paleozoic aquifer complex 0,005 1*10 − 6 1*10 − 6 1*10 − 6 Analysis of the modeling results shows different patterns of change in groundwater levels in the Eocene-Cretaceous and Paleozoic aquifer complexes (Fig. 11 ). In the Eocene-Cretaceous complex, dewatering is performed by wells located in depressions. Local cones of depression are formed, which merge into one cone around the mine. In the Paleozoic complex, water inflows decrease due to decreasing flow-over from the Eocene-Cretaceous complex, which is caused by wells of the Eocene-Cretaceous complex. The water budget for all scenarios (Fig. 12 ) shows a gradual decrease of mine water inflow. The rate of groundwater level decresasing significantly depends on the specific storage of the caved rock zone. It is clear from the water level graphs that in any case, with the Cretaceous aquifer being drained through six wells at a total outflow rate of 7,200 m 3 /day, reduction in groundwater levels to the target value in the geometric center of the caved rock zone will be achieved in less than two years from the start of drawdown (Fig. 12 ). Conclusions The cause of mud rushes at the Sokolov mine is groundwater that saturates sedimentary rocks (sands, clays) in the caved rock zone. The hydrogeological situation in the Sokolov mine area is determined by a combination of a number of factors. These are: the presence of a water-rich Cretaceous aquifer; mining using sublevel caving technique; the presence of a caved rock zone (1,600 m along the strike and 600 m across the strike), in which a artificial water-bearing rock mass is formed, connected with other aquifers; the hilly relief of the Cretaceous aquifer base, which persist saturated zone and cause the mine water inflow to the caved rock zone; the mine dewatering by an external drainage gallery. The strategy for improving the dewatering system to prevent mud rushes into the mine workings should be aimed at a more complete drainage of the Cretaceous aquifer. An effective method of drainage is drilling of the additional wells in the area between the caved rock zone and the external drainage gallery in local depressions where the elevations of the Cretaceous aquifer base are lower. Declarations Acknowledgements This work was supported by State Assignment of The Institute of Mining, Ural Branch of the Russian Academy of Sciences 075-00412-22 PR. Theme 2 (2022-2024) “Development of geoinformation technologies for evaluating the protection of mining sites and predicting the development of negative processes in land use” (FUWE-2022-0002) s. r. 1021062010532-7-1.5.1 This paper offers a new original research on the topic of underground mining dewatering and the prevention of mud rushes into mine workings. Unlike most publications on mud rushes, it considers hydrodynamic modeling for effective dewatering and safety purposes. The Authors declares that there is no conflict of interest. References Anderson MP, Woessner WW, Hunt RJ (eds) (2015) Applied Groundwater Modeling (Second Edition). In: Applied Groundwater Modeling (Second Edition). Academic Press, San Diego, p iv Butcher R, Stacey TR, Joughin W (2005) Mud rushes and methods of combating them. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4808030","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":334350454,"identity":"327e8c82-1952-4c38-82d6-5126173543ca","order_by":0,"name":"Liudmila Rybnikova","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAqklEQVRIiWNgGAWjYBACPjBpcECOgYGx8QBRWtigWoyBWhpI0cJwILEBRBKnRSL94eOKgjvpa9sPNxxg3HOYGC05xoZnDJ7lbjuTCHTYM+K0sEk2GBzO3XYApOUAUVrSn/8Eakk3O/+QaC0JZoxALQlmN4i2heeNMdBhzwy33QDaknAgnbAWfvb0hx8b/tyRNzuf/vDBhwPWhLWgggRSNYyCUTAKRsEowA4APcNBrrP3azYAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0002-4221-7879","institution":"Institute of Mining, Ural branch of RAS","correspondingAuthor":true,"prefix":"","firstName":"Liudmila","middleName":"","lastName":"Rybnikova","suffix":""},{"id":334350455,"identity":"c3ecb710-687d-4f4b-a0a9-3db9d4f4be77","order_by":1,"name":"Petr A. Rybnikov","email":"","orcid":"","institution":"Institute of mining, Ural branch of RAS","correspondingAuthor":false,"prefix":"","firstName":"Petr","middleName":"A.","lastName":"Rybnikov","suffix":""},{"id":334350456,"identity":"217e73ea-3c67-4ea5-a827-891367cf07f2","order_by":2,"name":"Evgenii Y. Efremov","email":"","orcid":"","institution":"Institute of Mining, Ural branch of RAS","correspondingAuthor":false,"prefix":"","firstName":"Evgenii","middleName":"Y.","lastName":"Efremov","suffix":""}],"badges":[],"createdAt":"2024-07-26 12:24:54","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4808030/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4808030/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":63480664,"identity":"2fbab88a-ce68-473a-88ef-1c03b7eb127e","added_by":"auto","created_at":"2024-08-28 14:54:37","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1760044,"visible":true,"origin":"","legend":"\u003cp\u003eStudy area map\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/97c2c7e6dca45fc78ed483b9.png"},{"id":63482076,"identity":"aaee8eff-6f11-47e9-a066-0722329af83c","added_by":"auto","created_at":"2024-08-28 15:10:37","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":270314,"visible":true,"origin":"","legend":"\u003cp\u003eCross-section of Sokolov deposit\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/601d6a4c81bdc253daefd97f.png"},{"id":63481411,"identity":"7c8513c0-87f7-468c-85ee-9bc4c2551886","added_by":"auto","created_at":"2024-08-28 15:02:37","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":4037693,"visible":true,"origin":"","legend":"\u003cp\u003eThe evolution of the caved rock zone from 2004 to 2023.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/3927338d0816bc6c28a06bd0.png"},{"id":63482075,"identity":"1bfe97be-da44-4817-b80a-442a2a877f8c","added_by":"auto","created_at":"2024-08-28 15:10:37","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":257007,"visible":true,"origin":"","legend":"\u003cp\u003eScheme of mud rush formation: а – initial stage of caved rock zone formation, b – terminal stage of caved rock zone formation, mud rush conditions have formed.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eKey: 1) Quaternary sandy loam, 2) Quaternary sand, 3) Quaternary clay, 4) Oligocene sand, 5) Chegan clay, 6) Eocene gaize, 7) Cretaceous sand, 8) Palaeozoic weathering crust (clay), 9) Palaeozoic high fractured massive rock, 10) Palaeozoic intermediate fractured massive rock, 11) Palaeozoic massive rock, 12) caved rock zone.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/8731909d397a8a65cd9fc310.png"},{"id":63482077,"identity":"00891516-313a-4836-9984-66268e2144c0","added_by":"auto","created_at":"2024-08-28 15:10:37","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":810310,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of the mud rushes into the mine workings of the Sokolov mine.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eMud rush volume (V, m\u003c/em\u003e\u003csup\u003e\u003cem\u003e3\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e): rank 1 \u003c/em\u003e→\u003cem\u003e V ˃ 100; rank 2 \u003c/em\u003e→\u003cem\u003e 100 ˃ V ˃ 8; rank 3 \u003c/em\u003e→\u003cem\u003e V \u0026lt; 8.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/31513a4d15d4d77880deee92.png"},{"id":63482713,"identity":"c014cfc4-a4ec-4ec0-bf50-ff03d4de4469","added_by":"auto","created_at":"2024-08-28 15:18:37","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":1530047,"visible":true,"origin":"","legend":"\u003cp\u003eGroundwater model domain, caved rock zone is associated with internal mine drainage.\u003cem\u003e Q\u003c/em\u003e\u003csub\u003e\u003cem\u003eK\u003c/em\u003e\u003c/sub\u003e\u003cem\u003e, Q\u003c/em\u003e\u003csub\u003e\u003cem\u003ePz\u003c/em\u003e\u003c/sub\u003e\u003cem\u003e – mine drainage from aquifer, thousand m\u003c/em\u003e\u003csup\u003e\u003cem\u003e3\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e/day. BC – boundary condition: DRN – drain, RIV – river, GHB – general head boundary\u003c/em\u003e\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/27fd8276ea7f03fa5b204a5b.png"},{"id":63481416,"identity":"414e815a-fd7a-4dd8-9c63-31bddde3d8c2","added_by":"auto","created_at":"2024-08-28 15:02:37","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":146107,"visible":true,"origin":"","legend":"\u003cp\u003eStratigraphy and hydrogeological grouping for Sokolov mine. \u003cem\u003eН – absolute elevations, m – thickness, k – hydraulic conductivity\u003c/em\u003e\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/b3d7a37735b0a7dbf13ea5b1.png"},{"id":63481412,"identity":"90353558-c28f-445e-8979-4583ae75f3d5","added_by":"auto","created_at":"2024-08-28 15:02:37","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":266733,"visible":true,"origin":"","legend":"\u003cp\u003eModel water budget and groundwater levels of the Cretaceous aquifer, stationary model, current conditions\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/0f507e131d7a713721cef6e4.png"},{"id":63481414,"identity":"815b5f13-08d5-42c0-be45-7efef59c0f74","added_by":"auto","created_at":"2024-08-28 15:02:37","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":221765,"visible":true,"origin":"","legend":"\u003cp\u003eDependence of mine water inflow on the hydraulic conductivity of the caved rock zone.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eK\u003c/em\u003e\u003csub\u003e\u003cem\u003ecz\u003c/em\u003e\u003c/sub\u003e\u003cem\u003e - hydraulic conductivity of caved rock zone, K\u003c/em\u003e\u003csub\u003e\u003cem\u003eK\u003c/em\u003e\u003c/sub\u003e\u003cem\u003e - hydraulic conductivity of Cretaceous aquifer.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/d78f00fddb2ba1b4d16162bf.png"},{"id":63480666,"identity":"96d8cecd-57b5-4020-b94d-7fd51538ea25","added_by":"auto","created_at":"2024-08-28 14:54:37","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":431735,"visible":true,"origin":"","legend":"\u003cp\u003eThe design of the Sokolov mine drainage system, taking into account the morphology of the Cretaceous aquifer base. \u003cem\u003eThe scale on the right shows the absolute elevations of the Cretaceous aquifer base, m\u003c/em\u003e\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/94a145c8a5ae33c1ceba9eb5.png"},{"id":63480671,"identity":"4bb640aa-f04f-49d1-8261-749bb66685be","added_by":"auto","created_at":"2024-08-28 14:54:37","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":3859618,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of water heads in the Eocene-Cretaceous aquifer complex 720 days after the start of the drainage operation project (scenario 3)\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/7ef0f54b73ad7d3084430a47.png"},{"id":63480675,"identity":"920adebb-c204-46bf-8d83-fb9562b5f4f5","added_by":"auto","created_at":"2024-08-28 14:54:37","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":120633,"visible":true,"origin":"","legend":"\u003cp\u003eResults of predictive modeling for the Sokolov mine (inset model)\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/8d6c7e50518fe122be87029a.png"},{"id":63482735,"identity":"8b41ad7f-dc6f-486e-b4d2-319d04917dce","added_by":"auto","created_at":"2024-08-28 15:18:50","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":20865585,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4808030/v1/bcd5025f-857f-412e-8394-17fd12695827.pdf"}],"financialInterests":"","formattedTitle":"\u003cp\u003eReducing the Risk of Mud Rushes in Sokolov Iron Mine\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe combination of geological structural features and mining engineering factors during mineral excavations can lead to the emergence of complicated hydrogeological conditions that pose a threat to the environment and mining operations. A common consequence of ground disturbance is mine water inflow and mud rush into underground mines (Butcher, Stacey, \u0026amp; Joughin, 2005).\u003c/p\u003e\n\u003cp\u003eModern practice of underground mining for copper, iron, and diamonds in steeply dipping thick ore bodies using sublevel and block caving systems leads to the formation of extensive caved rock zones. These appear on the earth\u0026apos;s surface in the form of conical depressions and sinkholes ranging from hundreds to thousands of square meters. Sinkholes disrupt the\u0026nbsp;base\u0026nbsp;of all overlying aquifers, resulting in the formation of new artificial aquifer complexes, which is a source of danger for mining operations. Mud rushes from the caved rock zone amount to tens and hundreds of thousands of cubic meters. They render unusable kilometers of mine workings, cause millions of tons of minerals to be lost, and threaten human lives.\u003c/p\u003e\n\u003cp\u003eThe problem of mud rushes was first described with reference to the Kimberlite-hosted diamond deposits in South Africa. The first accident was recorded in 1894 (Sutton 1897). Such accidents have repeatedly led to human casualties. Thus, for example, from 1947 to 1953 there were six accidents at De Beers mines, each killing between 10 to 27 people (Kuttner and Stewart 1953). The problem of mud rushes is characterized as a specific threat characteristic of kimberlite diamond deposits. One of the most recent accidents occurred in 2011 at the Dutoitspan diamond mine, where over 4,000 m3 of mud entered the mine workings (Holder et al. 2013).\u003c/p\u003e\n\u003cp\u003eIn the second half of the 20th century, the problem of mud rushes was encountered during the development of iron ore deposits in the Krivoy Rog basin (USSR,\u0026nbsp;Ukraine), where losses of clean and diluted ores total exceeded 550 million tons (Dubinin et al. 1989)\u003c/p\u003e\n\u003cp\u003eMud rushes are also typical for large copper deposits developed using block caving mining methods, the example being El Teniente, Chile. Over the period of 2001 to 2017, in just one of the sectors (Diablo Regimiento) of El Teniente mine, there were 94 in-rushes of wet muck and 282 in-rushes of non-wet muck recorded (Castro et al. 2017, 2018; Szczepiński 2019; Salas et al. 2022). Also known are accidents at the IOZ and DOZ mines of Block Cave Mine, PT Freeport Indonesia, where during mining, several dozens of major and minor accidents occurred due to mud rushes into the mine workings \u0026nbsp;(Syaifullah et al. 2006; Rubio et al. 2011; Wicaksono et al. 2012; Setyadi et al. 2013; Cahyadi et al. 2017).\u003c/p\u003e\n\u003cp\u003eAt the Sokolov iron ore mine (Republic of Kazakhstan), more than 250 accidents occurred between 2004 and 2018 due to mud rushes from the stopes. The largest accident occurred in 2005, when more than 150,000 m3 of water and 35,000 m3 of mixed sedimentary rock entered the mine workings to a depth of 400\u0026ndash;600 m with two human fatalities. More than 24,000 meters of mine workings were flooded with a mixture of water and clay. It took more than six months to restore the mine\u0026apos;s functionality (Efremov 2019).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy area\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSokolov iron ore deposit is located in the north of the Republic of Kazakhstan (Fig. 1) as a part of the Kostanay iron ore basin, one of the largest in Eurasia (contains 85% of the Republic\u0026rsquo;s iron ore reserves). The Sokolov deposit together with the Sarbay deposit located six kilometers from it form the Sokolov-Sarbay iron ore complex. Both deposits belong to the skarn type and have a similar structure; long-term drainage has resulted in a consolidated cone of depression with a radius of 10 km.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eGeological structure of the study area\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe elevations of the earth\u0026apos;s surface in the area of the deposit are at 180\u0026ndash;190 m. Two km south of the deposit is the river Tobol, in which water levels vary from 125 to 140 m. The deposit is located in Paleozoic metamorphic rocks, overlain by Meso-Cenozoic sediments. The latter contain a water-rich Cretaceous aquifer. The ore bodies are located at depths from 120 to 1600 m and below and dip at angle of 45 degrees.\u003c/p\u003e\n\u003cp\u003eSedimentary rocks of about 120 m in thickness occur in the upper part of the geological structure. The bedding of the rocks of different age and genesis forms several aquifers, separated from each other by impermeable layers. The following elements are distinguished in the hydrogeological section (Fig. 2):\u003c/p\u003e\n\u003cp\u003e1. The aquifer of Quaternary alluvial deposits does not feature continuous distribution. Its structure is determined by individual lens-shaped bodies of sand, sandy loam, and loam. The recharge is by infiltration, mainly due to snowmelt water.\u003c/p\u003e\n\u003cp\u003e2. The Oligocene aquifer is distributed throughout except in river valleys. It is composed of 2\u0026ndash;8 m thick layers of sand and is characterized by a hydraulic conductivity of up to 5 m/day. The recharge is by infiltration.\u003c/p\u003e\n\u003cp\u003e3. The Chegan clay layer, which is the regional aquitard, is distributed throughout with the exception of river valleys. Its thickness is up to 35 m\u003c/p\u003e\n\u003cp\u003e4. The Eocene aquifer is composed of gaizes of the Tasarak formation to a thickness of 45 m. In its natural state, the aquifer is under pressure, with the absolute elevation of the groundwater level at about 165 m. The hydraulic properties of the aquifer are generally quite low, with the conductivity at 0.01\u0026ndash;2.0 m/day and most commonly at 0.3\u0026ndash;0.6 m/day. The recharge of the aquifer is through the area where it reaches the surface, as well as by flow-over from the Cretaceous sands.\u003c/p\u003e\n\u003cp\u003e5. The Cretaceous aquifer is composed of quartz-mica and quartz-glauconitic sands. The aquifer spreads throughout and rests on the lignite clays and rubble-loam deposits of the weathering crust. The aquifer is confined; under natural conditions, the groundwater level is at 165 m. The thickness of the aquifer in the area of the deposit reaches 50 m. The hydraulic conductivity of the Cretaceous sands decreases from 20 m/day in the river valleys to 0.05 m/day towards the watershed (Edigenov 2013). The aquifer is recharged at sites where the regional aquitard has eroded.\u003c/p\u003e\n\u003cp\u003eIn the areas of the Sokolov and Sarbay deposits, there is no layer of Maastrichtian clays; therefore, the Eocene and Cretaceous aquifers are considered as a single Eocene-Cretaceous complex. This complex is the main source of water encroachment for the mine workings.\u003c/p\u003e\n\u003cp\u003e6. The weathering crust consists of lignite clays in thicknesses varying significantly from zero to dozens of meters, and up to 150 m in fault areas. The weathering crust presents a relative aquitard; the connection between the Cretaceous aquifer and the underlying aquifer complex is through hydrogeological windows at places where sands rest on the Paleozoic foundation.\u003c/p\u003e\n\u003cp\u003e7. The Paleozoic aquifer complex extends throughout and includes several stratigraphic divisions of the Silurian, Devonian, and Carboniferous.\u003c/p\u003e\n\u003cp\u003eThe rocks of the Paleozoic complex are represented by an effusive-sedimentary sequence composed of andesitic and basaltic porphyrites, their tuffs and tuff breccias, and less commonly, by limestones and tuffites of the Lower Carboniferous. The rocks feature diorite and diabase-porphyrite intrusions. Mineralization and formation of metasomatic rocks is confined to where effusive-sedimentary and intrusive rocks occur in contact.\u003c/p\u003e\n\u003cp\u003eGroundwater is confined to the upper fractured zone, where open fracturing is developed to a depth of 20\u0026ndash;40 m; in effusive sedimentary rocks and in zones of tectonic disturbances, it reaches a depth of 100 m or more (Veselov et al. 1992). The hydraulic conductivity of the rocks varies with depth, being 0.085 m/day in the upper part and decreasing to 0.0005 m/day in the middle.\u003c/p\u003e\n\u003ch2\u003eEffects of Mining\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eMining at the Sokolov deposit is carried out using a combined method: the larger southern part is developed by the open-pit mining, while the northern part by underground mining. The Sarbay deposit is developed by the open-pit.\u003c/p\u003e\n\u003cp\u003eThe northern part of the Sokolov deposit is mined using sublevel mining method. The shafts are located in the west in the basewall of the deposit. Ore bodies are accessed at 5 horizons at levels -60 m, -120 m, 190 m, -260 m, -330 m, and -400 m. At the moment, stoping is conducted mainly at the -330 m complex. Thus, the current depth of operations is about 500 m (Исанченко , Верин, \u0026amp; Раков, 2004).\u003c/p\u003e\n\u003cp\u003eFrom 1976 to 1998, the deposit was mined with the filling of the goaf. The caved rock zone began forming in 1981. In total, more than 100 craters emerged to the surface, many of which re-emerged in already formed craters.\u003c/p\u003e\n\u003cp\u003eCurrently, the caved rock zone on the surface measures about 1600 m in length and 600 m in width, oriented submeridionally (Fig. 3).\u003c/p\u003e\n\u003cp\u003eThe caved rock zone consists of four groups of individual pipe-shaped cones, and its shape is determined by the configuration of the ore bodies. To prevent the accumulation of water in open craters, since 2009 they are being filled with waste rock from the Sokolov open pit.\u003c/p\u003e\n\u003cp\u003eAs a result of mining the steeply dipping ore bodies, caved sedimentary material (sands, loams and clays, repeatedly mixed with each other and with rock) now is found below the main aquifer (Fig. 4).\u003c/p\u003e\n\u003cp\u003eThe presence of a large volume of mud in the caved rock zone and the influx from the Cretaceous aquifer lead to mud rushes and to mud pushing onto the haulage levels.\u003c/p\u003e\n\u003cp\u003eMud in mine workings presents a hazard to operations, leads to production delays, ore contamination, and decreasing productivity. An analysis of 250 events showed that the volume of mud rush varies from 1 m\u003csup\u003e3\u003c/sup\u003e to 37,000 m\u003csup\u003e3\u003c/sup\u003e. Most of the large (over 100 m\u003csup\u003e3\u003c/sup\u003e) wet mud rushes are localized in ore blocks located in the central and northern district of the mine field (Fig. 5) (Efremov, 2019).\u003c/p\u003e\n\u003cp\u003eAccording to monitoring data, the main source of influx to the caved rock zone is the Cretaceous aquifer, which provides 70% of the mine water inflow; another 15% of mine water inflow is from the Paleozoic aquifer complex, hydraulically connected to the Cretaceous. The remaining 15% of the mine water inflow is from the Oligocene aquifer.\u003c/p\u003e\n\u003cp\u003eTo ensure the drainage of the Cretaceous aquifer, the Sokolov mine and the Sokolov open pit are surrounded along the perimeter by an integral external drainage gallery at elevation +33 m. The drainage gallery consists of underground workings driven through Paleozoic rocks and is equipped with drainholes from drainage gallery and drainholes from surface to gallery to ensure drainage of the Cretaceous aquifer. In total, the perimeter of the workings surrounding the mine is 9.5 km long, and that around the open pit is 15 km. Over the lifetime of the external drainage gallery, Sokolov mine has been provided with 1,222 wells drilled from drainage gallery and 100 wells drilled from the surface to the drainage gallery.\u003c/p\u003e\n\u003cp\u003eTo date, the Cretaceous aquifer has not yet been completely drained; the thickness of the residual water head in the vicinity of the caved rock zone is 5\u0026ndash;20 m. In support of the efforts to increase the efficiency of the dewatering system, we have developed a groundwater model of the mining area exposed to hydrodynamic impacts.\u003c/p\u003e"},{"header":"Methods and materials","content":"\u003ch2\u003eData\u003c/h2\u003e\n\u003cp\u003eFor constructing the model, use was made of cartographic materials, mining plans, geological sampling data, open-pit and underground mine drainage monitoring results, and observations of groundwater levels.\u003c/p\u003e\n\u003ch2\u003eMethods\u003c/h2\u003e\n\u003cp\u003eThe groundwater conditions was simulated using MODFLOW with the Modelmuse interface, which is widely used for groundwater modeling (Harbaugh 2005), for predicting mine water inflow(Anderson et al. 2015; Szczepiński 2019; Shi et al. 2019; Maroney et al. 2022), and for karst aquifer modeling (Duran and Gill 2021).\u003c/p\u003e\n\u003cp\u003eAt the first stage, to calibrate the model, a series of inverse problems (in stationary formulation) were solved to reproduce the current hydrodynamic situation.\u003c/p\u003e\n\u003cp\u003eAt the second stage, a series of computational experiments were carried out to identify the dependence of mine water inflow on geofiltration parameters, primarily on the hydraulic conductivity of the caved rock zone, which cannot be determined using traditional methods.\u003c/p\u003e\n\u003cp\u003eAt the third stage, predictive scenario modeling was performed to assess the operating efficiency of the drainage facilities being designed.\u003c/p\u003e\n\u003ch2\u003eModel stratification\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eThe modeling area includes the Sokolov underground mine, and the Sokolov and Sarbay open pits. On the south, the area is delimited by the valley of the river Tobol (Fig. 6). In plan, the elements of the finite-difference grid have a square shape with a side of 200 m; the height of the model blocks corresponds to the thickness of the simulated layers. In the immediate vicinity of the area under study, the computational grid was refined to more accurately take into account the relief of the Cretaceous aquifer. The size of the refined grid\u0026rsquo;s cell is 50 m.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe presence of a layer of Chegan clays up to 35 m in thickness, which is a regional aquitard, accounts for the separation of the regimes of the Eocene-Cretaceous complex and the Oligocene aquifer. Under natural conditions, groundwater levels differed from each other by no more than 10\u0026ndash;20 m. As a result of mine drainage, the groundwater level of the Cretaceous aquifer decreased from 165 to 95 m, while that of the Oligocene aquifer remained almost unchanged and is still at 175 m.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The absence of a hydraulic connection between the Oligocene and underlying horizons, as well as the subordinate role of the Oligocene aquifer in the total water inflow, allows it to be disregarded in the model. Thus, the model includes the Eocene-Cretaceous and Paleozoic aquifer complexes, separated by the impermeable layer of the weathering crust (Fig. 7).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSince the conductivity properties of the Paleozoic rocks feature a clearly defined vertical zoning, the complex is represented by two model layers: the upper one (layer 3) corresponds to the zone of highly fractured rocks; the second, underlying one (layer 4), corresponds to a less disturbed zone (Fig. 7).\u003c/p\u003e\n\u003cp\u003eThe caved rock zone is considered as a separate hydrogeological element with its own conductivity and storativity parameters, which were determined through numerical experiments.\u003c/p\u003e\n\u003ch2\u003eBoundary conditions\u003c/h2\u003e\n\u003cp\u003eThe relationship between heads and outflow rates was simulated using boundary conditions of the third kind (Fig. 6). The outer boundaries of the model were considered as General Head Boundary (GHB); the values of the water head are set at a distance (through corresponding filtration resistance) such that enables one to reproduce the formation of a cone of depression in the course of aquifer drainage.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe river Tobol was modeled with the help of the River package (RIV); the parameters of bottom sediment resistance were determined during the calibration of the model.\u003c/p\u003e\n\u003cp\u003eGroundwater inflow to mine workings was modeled using the Drain package (DRN). The depths of the drains correspond to the following elevations: for the external drainage complex of the Sokolov underground mine \u0026ndash; to the elevations of the Cretaceous aquifer\u0026rsquo;s base; for the caved rock zone \u0026ndash; to the stoping depth; and for the open pits \u0026ndash; to the elevations of the side drainages. Drain resistance parameters were selected during model calibration by solving inverse problems using observational data on mine drainage.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eCalibration\u003c/h2\u003e\n \u003cp\u003eThe invariable parameters of the model were the morphology and conductivity of the layers, the geometric elements of the model and computational grid, and the position of the main waterflows.\u003c/p\u003e\n \u003cp\u003eIn the course of modeling, we refined the parameters of the boundary conditions and the conductivity properties of the caved rock zone for the Sokolov mine.\u003c/p\u003e\n \u003cp\u003eThe criteria for calibration of model were the matching of model and observation average annual mine water inflow and groundwater levels near the ore field of the Sokolov mine (Fig. \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e). The deviation of model inflows to drainages from observed ones did not exceed 3%. The residuals of model groundwater levels near the caved rock zone was \u0026le;\u0026thinsp;1 meter.\u003c/p\u003e\n \u003cp\u003eOutflow from model caused underground mine and open pits (49,500 m\u003csup\u003e3\u003c/sup\u003e/hour) is formed due to the inflow to model from the valley of the river Tobol (40%) and inflows from the external borders from the recharge areas of the aquifer complexes in the west, north and east (60%). The levels in the Cretaceous aquifer vary from 150 m in the east to 90 m near the mine and open pits. Drainage from the Sokolov and Sarbay deposits across most of the area has led to the formation of a common cone of depression, but there is a watershed between them with a groundwater level of about 100 m.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003eAnalysis of the effect of caved rock zone conductivity on mine water inflow\u003c/h2\u003e\n \u003cp\u003eSince it was difficult to define the conductivity properties of rocks in the caved rock zone directly, analysis of caved rock zone conductivity have done as numerical experiment. The range of variation in the conductivity of the caved rock zone K\u003csub\u003ecz\u003c/sub\u003e was taken to be from 0.125 to 15 m/day (Fig. \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e). The hydraulic conductivity of the Cretaceous aquifer in the area of the mine field can be considered as reliably determined at K\u003csub\u003eK\u003c/sub\u003e=2 m/day.\u003c/p\u003e\n \u003cp\u003eIncreasing or decreasing (almost by an order of magnitude) the hydraulic conductivity of the caved rock zone did not lead to any change in minewater inflow. A significant decrease in inflow to the drainage system occurred only for a more significant decrease in the conductivity of the caved rock zone (\u0026lt;\u0026thinsp;0.2 m/day). Accordingly, the main factor determining mine water inflow is the hydraulic conductivity properties of the Cretaceous aquifer.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003eForecasting simulation\u003c/h2\u003e\n \u003cp\u003eCurrently, the groundwater level of the Cretaceous aquifer in the Sokolov mine ore field varies from 90 to 100 m, with an average of 95 m (Fig. \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e). The morphology of the aquifer base is complex: there are numerous hills and depressions, with the elevation range of 30 m (Fig. \u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e). Along the perimeter of the caved rock zone, the saturated thickness is 5\u0026ndash;15 m, which means that the inflow from the Cretaceous aquifer persists. Despite operating drainage, the inflow of water to the caved rock zone occurs through saddle-shaped depressions between local elevations.\u003c/p\u003e\n \u003cp\u003eTo disrupt the hydraulic connection between the Cretaceous aquifer and the caved rock zone, it is necessary to reduce groundwater levels to the level of the aquifer base. Based on this consideration, the groundwater level at the border with the caved rock zone should not exceed 82 m. This will create conditions for groundwater drawdown in caved rock zone, the volume of which now amounts to 4.3\u0026nbsp;million m\u003csup\u003e3\u003c/sup\u003e, and prevent mud rushes.\u003c/p\u003e\n \u003cp\u003ePredictive modeling assumed the following starting points:\u003c/p\u003e\u003cspan\u003e\n \u003cp\u003e1. The target is to reduce the groundwater level in the Cretaceous aquifer near the caved rock zone to the elevation 82 m.\u003c/p\u003e\n \u003c/span\u003e \u003cspan\u003e\n \u003cp\u003e2. Drawdown is carried out using six wells (in addition to the existing drainage gallery) with a flow rate of 50 m\u003csup\u003e3\u003c/sup\u003e/hour (1200 m\u003csup\u003e3\u003c/sup\u003e/day) each. The wells are located in local depressions in the relief of the Cretaceous aquifer base and are modeled using specified flux boundary conditions.\u003c/p\u003e\n \u003c/span\u003e \u003cspan\u003e\n \u003cp\u003e3. The rate of drawdown at the geometric center of the caved rock zone is determined. Since it is impossible to determine reliably the specific storage of caved rock zone, scenario modeling was used depending on specific storage values for the caved rock zone\u003c/p\u003e\n \u003c/span\u003e\n \u003cul\u003e\n \u003cli\u003e\n \u003cp\u003escenario 1\u0026thinsp;=\u0026thinsp;the specific storage of the caved rock zone has increased as a result of deconsolidation;\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003escenario 2\u0026thinsp;=\u0026thinsp;the specific storage of the caved rock zone is equal to that of the main aquifer;\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003escenario 3\u0026thinsp;=\u0026thinsp;the specific storage of the caved rock zone has decreased due to gravitational compression (redeposition) (Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\n \u003c/li\u003e\n \u003c/ul\u003e\n \u003cp\u003eThe specific storage values of the weathering crust and the Paleozoic aquifer remained constant for all three scenarios.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eGroundwater model parameters\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eElement of model\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003ek, m/day\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"4\"\u003e\n \u003cp\u003eSpecific storage (S\u003csub\u003es\u003c/sub\u003e) for scenario, m\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCretaceous aquifer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCaved rock zone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWeathering crust of Paleozoic rocks\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0,0005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUpper part of the fractured zone of the Paleozoic aquifer complex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0,085\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLower part of the fractured zone of the Paleozoic aquifer complex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0,005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e1*10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eAnalysis of the modeling results shows different patterns of change in groundwater levels in the Eocene-Cretaceous and Paleozoic aquifer complexes (Fig. \u003cspan class=\"InternalRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eIn the Eocene-Cretaceous complex, dewatering is performed by wells located in depressions. Local cones of depression are formed, which merge into one cone around the mine.\u003c/p\u003e\n \u003cp\u003eIn the Paleozoic complex, water inflows decrease due to decreasing flow-over from the Eocene-Cretaceous complex, which is caused by wells of the Eocene-Cretaceous complex. The water budget for all scenarios (Fig. \u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e) shows a gradual decrease of mine water inflow.\u003c/p\u003e\n \u003cp\u003eThe rate of groundwater level decresasing significantly depends on the specific storage of the caved rock zone. It is clear from the water level graphs that in any case, with the Cretaceous aquifer being drained through six wells at a total outflow rate of 7,200 m\u003csup\u003e3\u003c/sup\u003e/day, reduction in groundwater levels to the target value in the geometric center of the caved rock zone will be achieved in less than two years from the start of drawdown (Fig. \u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe cause of mud rushes at the Sokolov mine is groundwater that saturates sedimentary rocks (sands, clays) in the caved\u0026nbsp;rock\u0026nbsp;zone.\u003c/p\u003e\n\u003cp\u003eThe hydrogeological situation in the Sokolov mine area is determined by a combination of a number of factors. These are:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003ethe presence of a water-rich Cretaceous aquifer;\u003c/li\u003e\n \u003cli\u003emining using sublevel caving technique;\u003c/li\u003e\n \u003cli\u003ethe presence of a caved rock zone (1,600 m along the strike and 600 m across the strike), in which a artificial water-bearing rock mass is formed, connected with other aquifers;\u003c/li\u003e\n \u003cli\u003ethe hilly relief\u0026nbsp;of the Cretaceous aquifer base, which persist saturated zone and cause the mine water inflow to the caved rock zone;\u003c/li\u003e\n \u003cli\u003ethe mine dewatering by an external drainage\u0026nbsp;gallery.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u0026nbsp;The strategy for improving the dewatering system to prevent mud rushes into the mine workings should be aimed at a more complete drainage of the Cretaceous aquifer. An effective method of drainage is drilling of the additional wells in the area between the caved rock zone and the external drainage gallery in local depressions where the elevations of the Cretaceous aquifer base are lower.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAcknowledgements\u003c/p\u003e\n\u003cp\u003eThis work was supported by State Assignment of The Institute of Mining, Ural Branch of the Russian Academy of Sciences 075-00412-22 PR. Theme 2 (2022-2024) \u0026ldquo;Development of geoinformation technologies for evaluating the protection of mining sites and predicting the development of negative processes in land use\u0026rdquo; (FUWE-2022-0002) s. r. 1021062010532-7-1.5.1\u003c/p\u003e\n\u003cp\u003eThis paper offers a new original research on the topic of underground mining dewatering and the prevention of mud rushes into mine workings. Unlike most publications on mud rushes, it considers hydrodynamic modeling for effective dewatering and safety purposes. The Authors declares that there is no conflict of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAnderson MP, Woessner WW, Hunt RJ (eds) (2015) Applied Groundwater Modeling (Second Edition). In: Applied Groundwater Modeling (Second Edition). Academic Press, San Diego, p iv\u003c/li\u003e\n \u003cli\u003eButcher R, Stacey TR, Joughin W (2005) Mud rushes and methods of combating them. J South Afr Inst Min Metall 105:817\u0026ndash;824\u003c/li\u003e\n \u003cli\u003eCahyadi TA, Widodo LE, Syihab Z, et al (2017) Hydraulic Conductivity Modeling of Fractured Rock at Grasberg Surface Mine, Papua-Indonesia. J Eng Technol Sci 49:\u003c/li\u003e\n \u003cli\u003eCastro R, Basaure Matsumoto K, Palma S, Vallejos J (2017) Geotechnical characterization of ore related to mudrushes in block caving mining. J South Afr Inst Min Metall 117:. https://doi.org/10.17159/2411-9717/2017/v117n3a9\u003c/li\u003e\n \u003cli\u003eCastro R, Garc\u0026eacute;s D, Brzovic A, Armijo F (2018) Quantifying Wet Muck Entry Risk for Long-term Planning in Block Caving. Rock Mech Rock Eng 51:2965\u0026ndash;2978. https://doi.org/10.1007/s00603-018-1512-3\u003c/li\u003e\n \u003cli\u003eDubinin NG, Khramczov VF, Shekhovczov VS (1989) Prevention of Mud rush in ore mines. IGD SO USSR publ, Novosibirsk\u003c/li\u003e\n \u003cli\u003eDuran L, Gill L (2021) Modeling spring flow of an Irish karst catchment using Modflow-USG with CLN. J Hydrol 597:125971. https://doi.org/10.1016/j.jhydrol.2021.125971\u003c/li\u003e\n \u003cli\u003eEdigenov M. B. (2013) Hydrogeology of Ore Deposits in North Kazakhstan\u003c/li\u003e\n \u003cli\u003eEfremov E. (2019) Characteristic of mud inrushes distribution from caved zone into deposit located under sedimentary structure. Bull Tomsk Polytech Univ Geo Assets Eng 330:126\u0026ndash;134. https://doi.org/10.18799/24131830/2019/12/2409\u003c/li\u003e\n \u003cli\u003eHarbaugh A.W. \u0026nbsp;(2005) MODFLOW-2005 : the U.S. Geological Survey modular ground-water model--the ground-water flow process\u003c/li\u003e\n \u003cli\u003eHolder A, Rogers A.J., Bartlett PJ, Keyter GJ (2013) Review of mud rush mitigation on Kimberley\u0026rsquo;s old scraper drift block caves. J South Afr Inst Min Metall 113:529\u0026ndash;537\u003c/li\u003e\n \u003cli\u003eKuttner R, Stewart HGH (1953) Safety and health at the Kimberley diamond mines. 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Water 11:848. https://doi.org/10.3390/w11040848\u003c/li\u003e\n \u003cli\u003eVeselov V.V., Makhmutov T.T., Edigenov M.B., et al (1992) Hydrogeology and environmental protection of mining areas of Northern Kazakhstan. Nedra Publishers, Moscow\u003c/li\u003e\n \u003cli\u003eWicaksono D., Silalahi P., Sriyanto I., et al (2012) Potential hazard map for the wet muck flow prevention at the Deep Ore Zone (DOZ) block cave mine, Papua, Indonesia. In: PROSIDING TPT XXI PERHAPI 2012\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"mine-water-and-the-environment","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"mwen","sideBox":"Learn more about [Mine Water and the Environment](http://link.springer.com/journal/10230)","snPcode":"10230","submissionUrl":"https://www.editorialmanager.com/mwen/default2.aspx","title":"Mine Water and the Environment","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Mudrush, mud rush, modflow, groundwater modelling, aquifer, mining drainage","lastPublishedDoi":"10.21203/rs.3.rs-4808030/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4808030/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMud rushes from the caved rock zone pose a danger to mining operations. Large ore deposits that are mined using sublevel caving systems are susceptible to this problem. The difficult hydrogeological conditions of the Sokolov iron ore deposit (Sokolov-Sarbay ore zone, Republic of Kazakhstan) necessitated the construction of a complex drainage system consisting of an external drainage gallery around the deposit that intercepts the main flux from the Cretaceous aquifer, and internal drainage facilities, which drain all aquifers within the caved rock zone. Despite the relatively effective operation of the drainage system, mud rushes of large volumes of water from the caved rock zone occur periodically. The most significant and dramatic event was the accident in 2005, which claimed two human lives and resulted in the flooding of 24 km of mine workings. It took six months to restore the mine. Smaller-scale accidents also cause significant damage since mud rushes and mud pushes lead to considerable downtimes and ore dillution, as a result of which mine productivity is significantly reduced.\u003c/p\u003e \u003cp\u003eThe paper considers the groundwater flow model of the Sokolov-Sarbay iron ore zone. Using scenario modeling, the study establishes the relationship between the hydraulic conductivity of the caved rock zone of the caved rock zone and mine water inflow into haulage level of the Sokolov underground mine. A forecast of mine water inflow is made, and mine drainage upgrading options are proposed for the purpose of improving mining safety and preventing mud rushes.\u003c/p\u003e","manuscriptTitle":"Reducing the Risk of Mud Rushes in Sokolov Iron Mine","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-28 14:54:32","doi":"10.21203/rs.3.rs-4808030/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major Revisions Needed","date":"2024-08-30T14:42:50+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-08-01T04:14:45+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-07-31T15:45:25+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-31T13:42:10+00:00","index":"","fulltext":""},{"type":"submitted","content":"Mine Water and the Environment","date":"2024-07-29T08:34:29+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"mine-water-and-the-environment","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"mwen","sideBox":"Learn more about [Mine Water and the Environment](http://link.springer.com/journal/10230)","snPcode":"10230","submissionUrl":"https://www.editorialmanager.com/mwen/default2.aspx","title":"Mine Water and the Environment","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"1d04a289-85b7-40e7-b6cf-16088c36c435","owner":[],"postedDate":"August 28th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-12-30T00:01:15+00:00","versionOfRecord":[],"versionCreatedAt":"2024-08-28 14:54:32","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4808030","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4808030","identity":"rs-4808030","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}