Underground Area Research Articles

Toward Healthy Underground Spaces: A Review of Underground Environmental Design Factors and Their Impacts on Users' Physiological and Psychological Health.

This study aims to review and synthesize what design factors are associated with the physiological and psychological health of occupants in underground spaces. The development of underground spaces offers options to global challenges, such as traffic congestion, urban overcrowding, the revitalization of dormant underground areas, disaster mitigation, and adaptation to extreme environments. Despite these advantages, concerns persist about potential adverse effects on human health in these environments. This situation underlines the necessity of systematically identifying concerns and perceptions related to health in underground spaces. A narrative literature review was conducted to examine the relationship between design factors and health factors across 21 empirical studies. Based on the review of the identified literature, a relationship diagram was developed to depict the interconnections between the identified design and health factors. The analysis identified design factors related to the air, sound, light, nature, transport, and spatial context of underground spaces, each of which exerted relationships with occupants' physiological and psychological health factors. The relationship diagram indicated that the psychological factor "feeling of confinement" was mentioned most frequently, suggesting that it is one of the most extensively researched factors in this context. The relationship diagram aims to bridge the existing knowledge gap and set the stage for future research endeavors. The ultimate goal is to refine urban living standards by leveraging the potential of underground spaces while ensuring health and well-being.

The Features of Creation of an Urban Building Environment with Completion of Underground Infrastructure Areas of the City of Yerevan

Underground areas are those parts of the city that can become the best way to overcome the expansion of the surrounding areas of the city, thanks to which new ideas can be created and developed, achieving eco-economic success, creating new opportunities to ensure people's livelihood and security. Underground areas can include transportation structures, passageways, industrial buildings, and public service infrastructure. Basically, the underground areas, developing vertically on several levels, extend under the crowded zones of the city center, in the areas adjacent to the transport hubs. The unloading of above-ground urban areas can lead to the positive process that freed areas will be used to create green zones, improving the sanitary and hygienic condition of the city. It will allow maintaining the existing urban environment, creating favorable conditions for improving people's living activities.

Integrated stable S isotope, microbial and hydrochemical analysis of hydrogen sulphide origin in groundwater from the Legnica-Głogów Copper District, Poland

Hydrogen sulphide (H2S) was first reported in 2010 in an underground mining area of the Legnica-Głogów Copper District (LGCD). However, during the deposit exploration and exploitation stage in 1970, H2S was not detected. Previous studies have not indicated the origin of H2S in LGCD mine waters. Indirect evidence has suggested that, most likely, H2S migrated with the groundwater from the Main Dolomite aquifer to the mine galleries through cracks in the separating anhydrite and halite layers resulting from long-term mining operations. Interdisciplinary studies have been conducted to confirm this hypothesis. Investigations of the δ34S in H2S of 12 groundwater samples taken from leakages from cracks in galleries and drilled boreholes showed high isotopic similarity to H2S in natural gas and S-organic compounds of oil from petroleum reservoirs in the Main Dolomite unit, where this gas was generated in high volumes mainly as a result of thermochemical sulphate reduction (TSR). Microbial investigations of mine water indicated the presence of Desulfitobacterales, Desulfobacterales, Desulfotomaculales, Desulfovibrionales, and Desulfuromonadia as possible indicators of contact between the analysed water and rocks inhabited by sulphur-reducing bacteria and Halothiobacillales, as an indicator of contact between water and salt. Hydrochemical analysis revealed that water flowing out of mine galleries and boreholes has a higher salinity than groundwater that is naturally associated with the horizon where mines operate; this phenomenon is associated with H2S occurrence. This investigation confirmed the hypothesis that the H2S in the LGCD mines originates mainly from the Main Dolomite aquifer. Furthermore, this study confirms that a multifaceted approach is necessary to answer complex geochemical questions in mining.

Characteristics and mechanisms of near-surface negative atmospheric electric field anomalies preceding the 5 September 2022, Ms 6.8 Luding earthquake in China

Abstract. A magnitude 6.8 strike-slip earthquake (EQ) struck Luding, Sichuan Province, China, on 5 September 2022, resulting in significant damage to nearby Ganzi Prefecture and the city of Ya'an. In this research, the near-surface atmospheric electric field (AEF) recorded at four sites 15 d before the Luding EQ was analyzed and differentiated, and multisource auxiliary data including precipitation, cloud base height, and low cloud cover were used at the same time. Nine possible seismic AEF anomalies at four sites were obtained preliminarily. Accordingly, microwave brightness temperature (MBT) data, which are very sensitive to the surface dielectrics and are closely related to the air ionization, together with surface soil moisture, lithology, and a 3D-simulated crustal stress field, were jointly analyzed to confirm the seismic relations of the obtained negative AEF anomalies. The geophysical environment for crustal high-stress concentration, positive charge carrier transfer, and surface accumulation was demonstrated to exist and to meet the conditions necessary to generate local negative AEF anomalies. Furthermore, to deal with the spatial disparities in sites and regions with potential atmospheric ionization, near-surface wind field data were employed to scrutinize the reliability of the AEF anomalies by comprehensively analyzing the spatial relationships among surface charges accumulation areas, wind direction and speed, and the AEF sites. Finally, four negative AEF anomalies were deemed to be closely related to the Luding EQ, and the remaining five possible anomalies were ruled out. A possible mechanism of negative AEF anomalies before the Luding EQ is proposed: positive charge carriers were generated from the underground high-stress concentration areas and then transferred to and accumulated on the ground surface to ionize the surface air, thus disturbing the AEF above the ground. This study presents a method for identifying and analyzing seismic AEF anomalies and is also beneficial for the examination of the pre-earthquake coupling process between the coversphere and the atmosphere.

Impacts of aquifer heterogeneity on subsidence resulting from engineering dewatering in the Lower Yangtze River plains

Study regionLower Yangtze River alluvial plain, China. Study focusThe uneven subsidence caused by dewatering in underground engineering constructions in densely populated areas of alluvial plains with an unevenly distributed medium has caused increased concerns. This study applied the transition probability geostatistical software (T-PROGS) geostatistical models based on data from 31 boreholes to characterize a three-dimensional (3D) heterogeneous aquifer (8.8×105 m2 in area and 56 m in depth) in an underground construction area in the alluvial plain of the lower Yangtze River. The SUB model was constructed to simulate the pumping-induced subsidence processes based on a reliable MODFLOW transit flow model. New hydrological insightsThe simulation results indicated that surface subsidence increased with pumping and reached a maximum of 33 mm by the end of the extraction (the 14th day). Surface subsidence development exhibited spatial anisotropy around the pumping center, consistent with the observations. Furthermore, the proposed model indicates that hydraulic head evolution and soil compressibility distributions significantly influence the spatial–temporal development of subsidence, implying the significance of the aquifer heterogeneity. The compressible soft soil overlying the pumping section was identified as a vulnerable subsidence zone, suggesting its significance for engineering geological surveys and dewatering designs in underground construction in alluvial plains.

Using mining waste for CO2 sequestration: exploring opportunities through mineral carbonation, nature-based solutions, and CCUS

ABSTRACT Using mining waste for CO2 sequestration presents a promising solution for managing waste and reducing greenhouse gas emissions. This article provides a comprehensive overview of established CO2 sequestration methods that can be applied to mining waste eligible for such application. Three techniques were considered: 1) passive mineral carbonation; 2) a nature-based solution (NBS); and 3) carbon capture, utilisation, and storage (CCUS). Passive mineral carbonation involves exposing mining waste rich in Ca and Mg silicates to atmospheric CO2. NBS explores the reclamation of disposal areas, estimating the carbon sequestration by topsoil, organic amendments, and revegetation. CCUS presents some storage possibilities with CO2 injection into waste piles and utilisation by incorporating waste and CO2 into cement products. Furthermore, an innovative proposal for injecting CO2 into surface and underground coal mining waste disposal areas was described as a potential action. The strategies presented in this article can be considered to offset CO2 emissions from mining projects while also contributing to waste management and more sustainable production.

Identification of Underground River Flow Using VLF (Very Low Frequency) and Geoelectricity at Karstic Area

Mapping underground river karst areas in the karst mountains Cianjur, West Java, has been done using electromagnetic methods and Geoelectricity Dipole-dipole. Karst constituent formation region of West Java area is limestone, clay stone, limestone fractured, hard and dense limestone, and limestone containing no water (rigid). The aim of this research is to search for the existence of underground rivers using electromagnetic and geoelectric wave surveys. VLF method consists of 13 line with a length of 750 m and a 10 m spacing. Based on the results of data processing VLF method is known that the equivalent current density (ECD) demonstrated high conductive rocks. While Geoelectricity method consists of 10 line, the arrangement is a parallel between the distance of the line with a space of 20 m andlength between 300 m.VLF data interpretation results indicate anomalous equivalent current density (ECD) with high scores range from 180-300% indicated fractured limestones are occupied by water, while the resistivity anomaly from 0.45 to 7.40 Ω.m indicated as weathered limestone layers accumulated dengn clay stone, resistivity values 186-701 Ω.m, fractured limestones indicated that fills with water. With sizes ranging 5-15 m cavity, each line with nearly the same distance at a depth of approximately 15-105 m, there is a large cavity-cavity interconnected.

Detection of Underground Dangerous Area Based on Improving YOLOV8

In order to improve the safety needs of personnel in the dark environment under the well, this article adopts the improved YOLOV8 algorithm combined with the ray method to determine whether underground personnel are entering dangerous areas and to provide early warning. First of all, this article introduces the coordinate attention mechanism on the basis of YOLOV8 target detection so that the model pays attention to the location information of the target area so as to improve the detection accuracy of obstruction and small target areas. In addition, the Soft-Non-Maximum Suppression (SNMS) module is introduced to further improve accuracy. The improved model is then combined with the ray method to be deployed and applied under a variety of angles and different scenic information cameras. The experimental results show that the proposed method obtains 99.5% of the identification accuracy and a frame speed of 45 Frames Per Second (FPS) on the self-built dataset. Compared with the YOLOV8 model, it has a higher accuracy and can effectively cope with the changes and interference factors in the underground environment. Further, it meets the requirements for real-time testing in dangerous underground areas.

Exploring Microbial Diversity in Green Honey from Pulau Banggi Sabah: A Preliminary Study

The microbiological composition of honey can include microorganisms that are beneficial or harmful to human health. Therefore, it is essential to investigate the microbiological quality of different honey types available in the market. However, there is limited information available on the analysis, isolation, and characterization of honey-associated microbes, especially for green honey from Banggi Island. Green honey is sourced from underground areas within the island's forest. This study aimed to assess the microbiological quality of raw (freshly collected) and processed green honey by examining the presence of bacteria, yeast, molds, and pathogens. The results revealed that raw green honey had a slightly higher total plate count (770 ± 0.03 cfu/g) compared to processed green honey (640 ± 0.02 cfu/g). Both raw and processed green honey contained Lactobacillus spp. with counts of 350 ± 0.02 cfu/g and 160 ± 0.02 cfu/g, respectively. Bacillus count was higher in raw green honey (110 ± 0.01 cfu/g) compared to processed green honey (5 ± 0.01 cfu/g). Molds were only detected in raw green honey, while osmophilic yeast counts were higher in raw green honey (16000 ± 0.03 cfu/g) compared to processed green honey (120 ± 0.02 cfu/g). Mesophilic bacteria, thermophilic bacteria, coliforms, E. coli, and Staphylococcus aureus were not detected in either raw or processed green honey. Furthermore, green honey was free from pathogenic bacteria such as Salmonella spp., Listeria spp., and Shigella spp. Bacteria isolated from green honey included Lysinibacillus macrolides, Lysinibacillus boronitolerans, Paenibacillus cineris, Paenibacillus favisporus, and Bacillus oleronius, none of which were pathogenic. This study identified important microorganisms present in green honey, which have the potential to provide beneficial effects without posing any harm to human health.

Strength distribution of cemented waste rock backfill: a similarity simulation experiment

Backfill of cemented waste rock into underground mined-out areas is an effective way to eliminate solid wastes and potential hazards in mines. To understand the backfill strength distribution law throughout the stope, similarity simulation experiments were conducted for direct-irrigating cemented waste rock backfill, and OpenCV and neural network were employed to analyze particle segregation and the spatial distribution of backfill strength. Results show that distinct gravitational segregation leads to an uneven and heterogeneous distribution of natural graded waste rocks in a similar model. Backfill strength near sidewalls and bottom of the model surpasses that of other areas. In the vertical direction, the average backfill strength increases with depth, ranging from 1.15 MPa at the topmost layer to 1.91 MPa at the bottommost layer. Horizontally, the average backfill strength near model boundaries is consistently higher than that at the model center, irrespective of the layer depth and orientation. Neural network prediction on spatial backfill strength proves reliable, exhibiting an average relative error of 4.12%, compared to the traditional surface fitting with a 10.20% error. Verification tests affirm the capability of the neural network model to accurately predict the anisotropic and nonlinear distribution of backfill strength in a large stope.

Innovative Method for Reliability Assessment of Power Systems: From Components Modeling to Key Indicators Evaluation

Power systems comprise different electrical, electronic, electromechanical and electrochemical components. Adequacy, security, resilience and reliability represent essential requirements for grids functioning mode. The evaluation of such aspects can constitute a delicate task in the presence of heterogeneous components. Focusing on reliability assessment, several Reliability Prediction Models are available. They are suitably applied according to the type of component under evaluation. The lack of homogeneity of these models forbids the comparison of performance and identification of unreliable systems and grid section. This paper aims to face the mentioned issue proposing a unique reliability assessment methodology able to characterize different equipment connected to radial/meshed/ring grids and subjected to different stressing and ageing factors. It is customized for electrical lines, transformers, circuit breakers, converters and renewables plants. Component and systemic key indices are calculated. Furthermore, a novel “load feeding reliability“ indicator is evaluated for providing information about the supply reliability of a specific load. This index is meaningful for the identification of unreliable grids, microgrids and systems. Such an approach can contribute to improve power systems design, planning and control. The proposed method is integrated in a software application implemented for grid reliability assessment. The obtained results are reported for an urban grid including an underground transportation area.

Navigation systems for agricultural machinery for adaptive-landscape farming

The GLONASS navigator is a versatile tool with diverse applications spanning air, sea, and land navigation. In agriculture, it facilitates adaptive-landscape farming by tailoring practices to specific soil and climate conditions, reducing search costs, and enhancing accuracy for surveyors and farmers. Beyond agriculture, GLONASS technology revolutionizes transportation by enabling shorter flight times, optimizing traffic flow, and even supporting aircraft control with autonomous landing prototypes. Its integration into various devices like watches, mobile phones, cars, and GPS-equipped dog collars further extends its utility. The widespread adoption of GLONASS in navigation and traffic management promises enhanced efficiency and safety across industries, including agriculture. As this technology evolves and becomes more accessible, its potential applications are poised to expand, offering exciting prospects for the future of adaptive-landscape farming and navigation across land, water, and air. While GLONASS is a powerful tool for navigation globally, it may face limitations in signal reception in underground areas like parking lots, caves, and chambers.

Hybrid method for analyzing air thermal conditions in underground mines

Thermal prediction of underground mine air is required to develop control measures against heat problems. Researchers have extensively studied this topic using numerical simulations; however, these require long processing times. Recently, researchers have begun using artificial intelligence algorithms; however, the predictive capabilities of the model are still limited because an intelligent system is formed from field measurement data. This study presents a fast and accurate prediction of the Wet Bulb Globe Temperature (WBGT) in underground mines using a hybrid integrated numerical method and an adaptive neuro fuzzy inference system (ANFIS) method. The mine air thermal conditions in various scenarios were analyzed by numerical simulation, and the results were utilized to develop intelligence for ANFIS model-based predictors. A case study was conducted in two underground gold mine areas to demonstrate the effectiveness of this method. The ANFIS model was trained and tested with 81 scenarios generated from numerical simulations. Accurate predictors were obtained, with a coefficient of determination (R2) of 0.98 and 0.97. In addition to predicting the WBGT, the developed ANFIS model optimized the selection of the auxiliary fan power, minimizing the power consumption while simultaneously providing a comfortable WBGT.

Investigation and analysis of spatial distribution of brine concentration in the underground brine mining area of the northern coastal area of Weifang City

Investigation and analysis of spatial distribution of brine concentration in the underground brine mining area of the northern coastal area of Weifang City

The Application of Three-Dimensional High-Density Electrical Method in Detecting Vertical HDPE Membranes at Landfill Sites

Landfilling is one of the important methods in hazardous waste treatment. In order to prevent the landfill leachate from connecting with external groundwater and prevent leachate from flowing into external polluted water bodies and soil, vertical anti-seepage membranes will be installed along the perimeter of the reservoir area. Given the structural characteristics of vertical HDPE membranes and site conditions, this study proposes the application of three-dimensional high-density electrical resistivity (3D-HDER) tomography for the detection of these membranes. Compared with the traditional resistivity method, the high-density resistivity method can realize automatic switching of electrode device type, electrode spacing and measuring points during the measurement process, thereby improving detection accuracy and work efficiency. By employing 3D-HDER for data collection on vertical HDPE membranes and inverting the subsurface resistivity distribution, the presence of leaks can be inferred based on the distribution of low-resistivity anomalies in the target underground area, thereby facilitating the integrity assessment of the vertical HDPE membranes. This research was applied in a practical investigation at a municipal landfill site in Hunan Province, where field tests were conducted, and the effectiveness of 3D-HDER in detecting vertical HDPE membranes was validated through excavation. The experimental results indicate that: (1) 3DHDER is capable of effectively and accurately locating shallow leaks, and (2) low resistivity anomalies were observed in the vicinity of the leaks.

Ways of Development of Modern Urban Environment in the Context of Appropriation of Underground Spaces

Today, in many countries of the world, the appropriation of underground areas is directly related to urban planning and development. If, until now, the subsoil was considered a technical area through which the engineering and technical infrastructures passed, a new task is presented: to develop the principles of functional zoning of the given areas by the master plan of the city, which is considered in the article. The purpose of this article is to develop a method of systematic appropriation of underground areas, which will contribute to the solution of socio-economic problems in the context of urban development. During the research, a study of local and international experience was carried out, on the basis of which an analysis of the situation of underground and above-ground areas was developed in the context of the urban environment, on the example of Yerevan. A methodology was formed based on the principle of effectiveness of the interconnection of the discussed underground and above-ground areas and the application of new volume-spatial approaches.

THE RESULTS OF THE RESEARCH OF THE UNDERGROUND FLOOR OF THE HOUSE 5 ON F. SKORYNA AVENUE

The article presents the results of the field studies of the ground floor in the eastern part of the former hotel complex “Grand Hotel” on the corner of Lenina Street and F. Skoryna Avenue. The clearing of the underground areas, filling of the vaults above the basements and the scoping work on the walls helped us to reveal a number of structures and archaeological artifacts from different times related to the architectural history of this building and the various institutions inside it. In particular, the artifacts related to the functioning of this building as one of the "Grand Hotel” complex buildings, which was located here before 1917 and now is being revived by a new owner, are of interest for the research.

Risk assessment of metro tunnel evacuation in devastating urban flooding events

Due to the increased frequency and magnitude of urban flooding events, there is an urgent need to study evacuation safety and disaster risk reduction in inundated urban underground spaces. In the literature, there is still a lack of methodologies to assess flooding risk in urban underground areas, which can account for the mutual effects of hydrodynamic characteristics, fluid-human interactions, and human behaviors. This study presents a hybrid model to investigate flood-induced evacuation safety in a metro tunnel based on the coupling of the hydrodynamic module, the human instability module, and the human behavior module. Firstly, floodwater conditions and flow characteristics are calculated by the hydrodynamic module. It is found that evacuation speed decreases with an increase in flow velocity and water depth. The water depth obviously increases after the flow passes the train where the flow velocity decreases with an increase in pressure due to the inference of the obstacle. Secondly, both depth-averaged velocity and depth of floodwater are used as the input parameters for the behavior module and stability module, and the flood hazard regimes for children and adults are then determined in an inundated metro tunnel. The relatively safe evacuation moving speeds for a child and an adult is suggested to be less than 0.5 m/s and 0.6 m/s, respectively. This study provides a novel approach to predicting the evacuation process and supports an early warning system in flood-prone underground areas for sustainable cities.

RADAR/INS TIGHTLY-COUPLED INTEGRATION FOR LAND VEHICLE NAVIGATION

Abstract. Multisensor systems are essential for autonomous navigation applications to achieve reliable accuracy. Integrating the Global Navigation Satellite System (GNSS) and the Inertial Navigation System (INS) is the most common integration scheme. However, this integration is unreliable in different scenarios since the GNSS signal may deteriorate in downtown areas or suffer from a blockage in underground and indoor areas. Therefore, other sensors are integrated with INS to compensate for GNSS outages. This paper proposes a novel algorithm for radar/INS tightly-coupled integration for autonomous navigation applications. This algorithm is applied in multiple steps. Radar data analysis is the first and most crucial step to remove the noisy data and the outliers and keep the useful objects. Then, data association is done to match the detected objects between radar frames. The tightly-coupled integration is performed at the measurement level through an Extended Kalman Filter (EKF), where the distance between the INS and the detected objects can be predicted from the INS and measured from the radar. Real data was collected from four Frequency Modulated Continuous Wave (FMCW) radar units in Calgary's suburban areas and Toronto's downtown area. The proposed algorithm was tested and assessed by introducing simulated GNSS single outages with different durations. The results show an enhancement in the vehicle's position by about 94% to 96%.

Wastes in Underground Coal Mines and Their Behavior during Mine Water Level Rebound—A Review

Backfill materials of various origin and composition, abandoned machinery, oils, PCB, gallery support material and cables are the main wastes occurring in underground coal mines during the period of their abandonment. Bearing in mind that under increasing societal pressure most if not all underground coal mines are going to close sooner rather than later, it is important to understand the interactions of these waste materials with rising mine water during mine water level rebound to prevent adverse environmental effects, especially on surface and groundwater. To this end, the composition of mine water at decant points as well as the hydrogeochemical, temporal and spatial dynamics of mine water during rebound requires quantification. In the first part of this paper, an overview of waste materials in underground coal mines is presented. The second part focusses on the experiences gained in the Ruhr area, a closed underground coal mining region in western Germany, where mine water rebound has been ongoing for decades. In this regard, the mine water modeling program Boxmodell was applied during regulatory approval procedures to predict the hydrodynamics and hydrogeochemical development of the water rebound. The results of these investigations allow deep insights into the interactions of rising mine water with wastes as well as the complex chemical evolution of mine water and potentially occurring contaminants (e.g., PCB). The experiences regarding wastes in underground coal mines and the geochemical evolution of rising mine water gained in the Ruhr area can be utilized to support the planning of mine closure in currently still active underground coal mining areas worldwide.