Rock Movement Research Articles

Low-Power and Wireless Communication Research on Underground Displacement Three-Dimensional Monitoring System.

Underground displacement monitoring is a crucial means of preventing geological disasters. Compared to existing one-dimensional methods (measuring only horizontal or vertical displacement), the underground displacement three-dimensional measurement method and monitoring system proposed by the author's research team can more accurately reflect the internal movement of rock and soil mass, thereby improving the timeliness and accuracy of geological disaster prediction. To ensure the reliability and long-term operation of the underground displacement three-dimensional monitoring system, this article further introduces low-power design theory and Bluetooth wireless transmission technology into the system. By optimizing the power consumption of each sensing unit, the current during the sleep period of a single sensing unit is reduced to only 0.09 mA. Dynamic power management technology is employed to minimize power consumption during each detection cycle. By using Bluetooth wireless transmission technology, the original wired communication of the system is upgraded to a relay-type wireless network communication, effectively solving the problem of the entire sensing array's operation being affected when a single sensing unit is damaged. These optimized designs not only maintain monitoring accuracy (horizontal and vertical displacement errors not exceeding 1 mm) but also enable the monitoring system to operate stably for an extended period under harsh weather conditions.

Analysis of Dynamic Evolution of Surrounding Rock Movement and Stress-Fracture in the Upward and Repeated Mining of Close-Distance Coal Seams

The distribution of mining-induced stress and the resulting rock fractures are two crucial factors affecting mineral extraction in protective layer mining. This research establishes a correlation between the vertical fracture aperture and the second derivative of the rock layer’s subsidence curve equation. The article explores the span requirement for a simply supported beam to fracture. This condition is relevant to understanding the dynamic evolution of rock movement and stress fractures during repeated mining of close-distance coal seams. Our study investigates alterations in rock stress and fractures resulting from repeated upward mining of coal seams, using the nearby coal seam cluster in Jincheng Mine as a case study. The research findings indicate that during the mining of the upper coal seam, the roof experiences significant but brief periodic loading intervals, as well as severe and moderate periodic loading. As mining progresses to the lower coal seam, pressure relief of the upper coal seam gradually increases in both degree and range. In the upper coal seam, the vertical stress distribution follows a sequence of “V,” “U,” and “W” forms. The upper coal seam undergoes five stages of expansion deformation: compression, expansion, increased expansion, decreased expansion, and stable expansion.

Seismic behavior of resilient composite steel plate shear wall using experimental investigations

Using composite encased steel plate shear wall (C-SPSW) has been attractively raised for enhancing the lateral seismic performance and increasing the useful floor area. Although, the experimental investigations have proved excellent dynamic behavior of C-SPSWs, structural damage as well as residual displacements are the main disadvantages of C-SPSWs, which are not consistent with low damage design (LDD) approaches. In the current study, the C-SPSWs performance is improved using the self-centering (SC) technique to control the both structural damage and reduce residual displacements as well. Five tests on C-SPSWs including three SC composite encased steel plate shear walls (SC-C-SPSWs) were conducted under gravity and lateral cyclic loads. The SC-C-SPSW consists of C-SPSW equipped with unbonded posttensioned tendons (UPT) to have resilience ability. For this aim, two symmetrical gaps were provided at the ends of the wall, and the UPTs were mounted at the wall ends and crossed into the foundation through the middle of the gaps. Under lateral load, the gap opening allows the elongation of UPTs that induce a high restoring forces, forcing the wall to have rocking movement above the foundation. In comparison with C-SPSWs, the SC-C-SPSWs exhibited low damages, higher shear strength capacity between 28% and 35%, larger ultimate drift capacity and more displacement ductility as 45–136% in average. Furthermore, the SC ability and the UPTs restoring forces effectively reduced the residual drift and the SC moment causes the recovery of the residual drift between 90% and 105%. Moreover, compared to C-SPSWs, the residual lateral strength of SC-C-SPSWs was improved by 30% in average.

Non-Pharmacological Intervention for Personalizing Sleep Quality through Gentle Rocking Motion.

Achieving restorative sleep is crucial for overall well-being, yet sleep difficulties affect a substantial portion of the adult population. Sleep disturbances are associated with diminished quality of life, physical complaints, cognitive impairment, and emotional regulation challenges. This study explores the influence of an innovative experimental bed designed to generate rocking motions on sleep parameters. A prospective observational study enrolled 60 adult participants, assessing their sleep on a regular stationary bed and the Inoveris bed, providing gentle rocking movements. Polysomnography was conducted, recording electroencephalography, electrooculogram, electromyogram, respiratory effort, and other parameters. The rocking bed significantly increased total sleep time (TST) and reduced N1 sleep stage duration (p < 0.001). Participants also experienced a quicker transition to the N2 sleep stage (p = 0.01), indicative of a faster shift from wakefulness to deeper sleep. Additionally, rocking led to a higher percentage of N1 sleep stages (p = 0.01) and a significant increase in N3 sleep stage duration (p = 0.004). While some results lacked statistical significance, notable trends in the rocking bed group have clinical relevance, consistently improving sleep parameters, including increased TST. The rocking bed also showed a trend towards higher sleep efficiency (SE) and sleep duration percentage, hinting at a potential overall enhancement in sleep quality. This study contributes valuable insights into the potential benefits of rocking motions on sleep architecture. Despite variations in outcomes across studies, our results underscore the potential of rocking beds as a non-pharmacological intervention for enhancing sleep quality. Notable improvements in total sleep time (TST), N1 sleep stage reduction, and accelerated transitions to deeper sleep stages highlight the clinical relevance of rocking interventions. Further research, collaboration, and addressing the identified limitations will advance our understanding of the therapeutic applications of rocking motions in sleep science.

Mechanism of Stratum Instability and Dynamic Deformation under Discontinuous Boundary Conditions

A fault disrupts the continuity of the rock strata in a mining area. To study the law governing the fracture of overlying strata in mining areas under discontinuous boundary conditions, the overlying strata were redefined and grouped based on the activity characteristics of each rock layer during the overall movement of the overlying strata. The activity patterns of different layers of the fault were obtained through the movement and failure forms of each group of rock layers. The relationship among the size of the coal pillar at the boundary of the fault, the dip angle of the fault, and the movement angle of the rock strata was considered. A model of the spatial relationship between the overlying rock movement zone of the quarry and the fault surface was established. The limit equilibrium equations of the key layer in the fault zone before breaking were established based on the tensile strength of the rock layer. In addition, the mechanical slip instability criterion and the deflection instability criterion of the discontinuous-boundary rock mass are given herein. Based on a field case, a double criterion was used to determine the initiating activated rock layers of the fault in the cases where the fault dip was smaller than the rock movement angle. Rock movement during excavation was simulated by similar simulation tests, and different levels of rock movement patterns in the boundary fault zone were focused on monitoring and analyzing. The stress and displacement changes in different rock layers in the fault zone were analyzed with numerical simulation results. The results show the following: if the dip angle of the fault is smaller than the movement angle of the rock layer, the delamination space of the fault surface is mainly distributed in the bending and sinking zone of the overlying rock; with an increase in the working-face advancement distance, the vertical pressure of the upper part of the fault gradually decreases, and the stress-concentration area in the middle and lower part of the fault gradually increases; the rock layer of the upper part of the fault, which is mainly composed of the key stratum, is the main area of activation of the fault.

Landslide risk management using geospatial technique: comparative insights of China and Indonesia

Landslides are defined as the movement of soil and rocks that form slopes. Landslides can cause environmental damage, property losses, and deaths for people in disaster-prone areas. This study aims to review and compare landslide risk management patterns in China and Indonesia from research conducted in 2019-2023. The method used in this study is a Systematic Literature Review (SLR). While searching for literature using Scopus, Mendeley has a publication period of 2019-2023. The research findings show that disaster risk management also focuses on more than community knowledge in disaster emergency response. However, other elements need attention, namely road sections most vulnerable to landslides, slope conditions, river density, land use, GIS, resources, community participation, and training. In Fengjie County, China, landslide vulnerability is a significant problem, with about 70% of areas in the vulnerability zone very high. In Pengasih Sentolo district, Indonesia, nine villages are included in the very high-risk site, showing significant landslide vulnerability. The integration and application of GIS technology have greatly assisted in assessing landslide susceptibility and identifying high-risk zones. Conclusion: The case study in Fengjie County, China and the study in Pengasih Sentolo District, Kulon Progo, Indonesia, emphasize the importance of using geospatial techniques, particularly GIS, for landslide risk assessment.

Slope Failure of Shilu Metal Mine Transition from Open-Pit to Underground Mining under Excavation Disturbance

The instability of slopes and ground subsidence caused by the conversion from open-pit to underground mining are important aspects of mining disaster research. This study focuses on the instability of slopes and ground subsidence during the conversion from open-pit to underground mining in the Beiyi mining area of the Shilu iron ore mine. Using numerical simulation and analysis, this study establishes a mechanical analysis model to assess the rock stability and movement of rockfall. The research findings indicate that there are significant stress concentration phenomena in the surrounding and floor areas of the goaf during the mining process. The collapse zone mainly develops in the western area before and after a certain level of mining and then shifts to the eastern part of Beiyi area. Surface subsidence expands after mining at a certain level, resulting in a large-scale disturbance area. Furthermore, the eastern slope experiences extensive landslides. This study suggests the continued monitoring of landslides and slope stability in specific areas of the mine. The research results can help us to understand the stability of the open-pit to underground rock mass in Hainan, judge the development trend of the surface subsidence range, and provide a reference for the stability evaluation of the rock mass mined by the open-pit-to-underground caving method.

Flyrock in surface mining Part II - Causes, sources, and mechanisms of rock projection

The fracturing and movement of rock that occurs in the vicinity of a stemmed borehole charge in open pit mining operations are described by examining the effects of the emitted stress waves - shock and elastic - and the expansion of high-pressure detonation product gases. Three principal modes of momentum transfer to fractured rock are identified, all linked to gas expansion work. This work can be delivered radially (burden), axially (stemming), and in the collar zone (cratering). Flyrock is generated under unusual combinations of blast parameters and rock properties. Although infrequent and seldom predictable, the generation of flyrock can nonetheless be interpreted and modelled in terms of the principal mechanisms of rock projection described in this study. The physical processes underlying these principal mechanisms are identified and will permit the development of predictive models for flyrock velocities.

Retracted: Study on Dynamic Evolution of Overburden Rock Movement and Mining-Induced Stress of Ultra-high Working Face

Retracted: Study on Dynamic Evolution of Overburden Rock Movement and Mining-Induced Stress of Ultra-high Working Face

Deformation as a process to transform shape and volume of protective structures of the development mine workings during coal-rock mass off-loading

Purpose is to assess deformation characteristics of protective structures while coal-rock mass off-loading to ensure wall rock stability as well as operating conditions of the development mine workings in coal mines. Methods. In a laboratory environment, uniaxial compression of protective structures has been applied on the models to identify the influence by deformation processes on the changes in their rigidness resulting from the shape and volume transformation. Findings. Under the deformation of rigid structures in the context of a safe strain resource, potential energy of their changes in shape is 4.1-6.5 times higher than the one of changes in volume. Beyond the safe deformation resource when critical level of the specific potential strain energy has been exceeded, strength of protective structures is not sufficient to restrict wall rock movement limiting their use. If relative volume variation in the rigid protective structures is δV &gt; 0.06-0.082 then they lose their stability. Under such conditions, structural rigidity decreases by 14-22%. If pliable wooden protective structures are used then relative 0.62 ≤ δV ≤ 0.72 volume change doubles their rigidity. In the circumstances, the potential shape change energy is 2.1 times higher than the volume change energy; the abovementioned favours temporary compaction of wooden components of the compressive structure while improving its resistivity. Originality. Regularities of changes in the specific potential deformation energy of protective structures depending upon their shape and volume variation in terms of uniaxial compression have been identified. Practical implications. To ensure stability of wall rocks and maintain operating conditions of the development mine wor-kings, it is reasonable to apply pliable wooden protective structures which will help restrict roof and floor movements after their compaction. Insufficient residual strength of rigid protective structures, resulting if they lose their stability, provokes rock failure within the working areas of coal mines.

Деревянные предметы из древнекорякского захоронения в нише на мысе Братьев, обнаруженные С. П. Ефимовым в 1976 году (залив Бабушкина, Северное Приохотье)

The relevance of studying the ancient Koryak culture of the Northern Okhotsk region is noted. A difficult problem is the study of its funeral rituals. One of the most promising sites for studying the ancient Koryak burial complexes is Cape Bratyev and Cape Bukhty Malaya Astronomicheskaya. The article discusses wooden items from the burial in the niche under a stone at Cape Bratyev in the area of Babushkin Bay. The wooden objects are identified as parts of a compound bow. The closest to Cape Bratyev bow fragments are ancient Eskimo bows. Information is provided about wooden finds at ancient Koryak sites. The presented data demonstrate the research potential of the ancient Koryak burial complexes in the Northern Priokhotye. The unsatisfactory condition of some burials, as well as natural destruction of the rock cliff and movement of boulders, among which the burials are located, determine the need for immediate research of these archaeological sites.

A landslide dating framework using a combination of Sentinel-1 SAR and -2 optical imagery

Landslides are mass movements of rock or soil down a slope, which may cause economic loss, damage to natural resources and frequent fatalities. To support risk management, landslide dating methods can provide useful knowledge about the date of the landslide and the frequency of occurrences, and thus potential triggers. Remote sensing techniques provide opportunities for landslide dating and are especially valuable in remote areas. However, the use of optical remote sensing is frequently hampered by cloud cover, decreasing the success rate and accuracy of dating. Here, we propose a landslide dating framework that combines the advantages of optical and SAR remote sensing satellites, because optical monitoring provides spectral changes on the ground and microwave observations provide information on surface changes due to loss of coherence. Our method combines Sentinel-1 and -2 satellite data, and is designed for cases wherein the landslide causes vegetation decrease and terrain deformation resulting in changing Normalized Difference Vegetation Index (NDVI) and SAR backscatter values. This landslide dating framework was tested and evaluated against 60 published landslides across the world. We show that the mean accuracy of landslide dating reaches 23 days when using combined Sentinel-1 and -2 imagery, which is a pronounced improvement compared to using only optical Sentinel-2 images resulting in an accuracy of 51 days. This study highlights that a combination of optical and SAR remote sensing monitoring is a promising technique for dating landslides, especially in remote areas where monitoring equipment is limited or which are frequently covered by clouds. Our method contributes to identifying failure mechanism by providing reliable date ranges of landslide occurrence, assessing landslide hazard and constructing landslide early warning systems.

Gentle Motion, Deep Sleep and Enhanced Rehabilitation: Investigating the Impact of Rocking Movements on Sleep – A Narative Review

Sleep plays a crucial role in physical and mental well-being, being a fundamental component of the body's natural rehabilitation and recovery process. Adequate sleep not only facilitates tissue repair but also enhances cognitive function and mood. For those undergoing physical rehabilitation or recovering from injuries, prioritizing restorative sleep is indispensable, as it accelerates healing processes. Recent studies explore innovative technologies like rocking movements to enhance sleep quality. While anecdotal evidence suggests benefits, scientific literature on rocking movements remains limited. This narrative review examines the impact of rocking movements on sleep quality and memory processes. Studies suggest potential benefits, such as such as a shorter duration of N1, increased spindle density in the N2, and longer time spent in N3, indicating enhanced sleep quality. The potential relevance of these findings lies in advancing non-pharmacological treatments for individuals with insomnia or mood disorders, and they may also have implications for foraging populations dealing with reduced deep sleep and memory impairments. Further research in clinical settings is imperative to explore the impact of sleep quality on rehabilitation training, determining if the positive influences of sleep consolidation translate into substantial clinical outcomes in rehabilitative care.

Combination of digital image processing and random generation in modeling soil-rock mixture slopes for post-failure analyses by material point method

Numerical analyses for the post-failure behaviors of soil-rock mixture (SRM) slope often encounter the difficulties of reconstructing the highly heterogenous soil-rock structures. The digital image processing can shape rock blocks but fails to capture the soil composition. Random generation technique, on the other hand, can constitute the soil particles fitting the grading curve but fails to shape the irregular rock blocks. In this study, we combine these two techniques to analyze the post-failure behaviors of SRM slope by material point method (MPM). Firstly, the digital image processing technique is introduced for separating rock blocks and soil particles in SRM slope domain; then the soil particles are further constituted according to grain size diagram by the random generation. After the verification of the present method, the effects of soil composition on the instability and failure modes of SRM slopes are studied. The MPM results show that the increase of clay proportion can significantly change the failure mode of SRM slope, induce a larger run-out distance of landslide mass, and pose a threat to the further rock movements and even landslide.

Permafrost conditions of the Subpolar Urals based on studies of lateral moraine peatlands

ABSTRACT Modern permafrost conditions of the Subpolar Urals are characterized by the example of peat bogs of the lateral moraine in the vicinity of Narodnaya mountain area (Polar Urals, Russia). Changes in permafrost conditions due to warming, studied by georadar survey and radiocarbon dating. The depth of thawing in these bogs was also determined by measuring the depth of the seasonally thawed layer and the temperature of the rocks using a thermometer and a metal probe 1.5 m long along a 100 m profile with a step of 10 m. It was found that the depth of the STL ranged from 10 to 140 cm at a permafrost surface temperature of 0 °C. The structure of the peat deposit was checked on a dry section of the swamp using a pit 40 cm deep. It was found that the peat bog is underlain by frozen clay-loam. In the peatland itself, several boundaries of peat and gley accumulation are visible in the layers directly above the underlying loam, which indicates a repeated change in the conditions of peat accumulation at the beginning of warming or the movement of rocks as a result of solifluction flows from nearby slopes.

Research on Rock Movement Control Method in Underground Mining Based on the Action of Granular Lateral Pressure

Research on Rock Movement Control Method in Underground Mining Based on the Action of Granular Lateral Pressure

Experimental Study on the Characteristics of Overlying Rock Movement in Mining Area

Experimental Study on the Characteristics of Overlying Rock Movement in Mining Area

Research Development and Critical Problems Existing in Strata Movement and Its Control

Under the guidance of green mining and scientific mining ideas, strata movement and its control have achieved a series of research developments in China. Based on the summary of research achievements related to strata movement characteristics, the influences on mining activity and surface environment, and the utilizing and controlling methods, critical problems that need to be solved are identified for a study on strata movement and its control. Mining activities will cause the redistribution of mining stress. The overlying strata incurs deformation, breaking, and movement under this mining stress. During this period, energy accumulation and release will occur in the roof strata, and the initiation and expansion of overburden fractures will occur. This demonstrates the impact of mining activities on underground safety and the ground environment. Thus, strata movement characteristics in longwall faces should be emphasized in the future. At present, the rock movement is still in the stage of qualitative description. Monitoring the movement of overlying strata in the stope and making predictions according to the monitoring results play a great role in ensuring the safety of mining production. Furthermore, system stiffness theory and intelligent control techniques for overburden strata should be developed.

Similar simulation of overburden movement characteristics under paste filling mining conditions

The method of filling mining can solve the problem of surface subsidence caused by coal mining. Among them, it is crucial to study the mechanism of filler strength improvement timeliness and filler mining to control rock movement for filler mining. In this paper, by combining theoretical analysis and similar simulation experiments, compressive strength is used as the research parameter to conduct proportioning test research on paste filling similar materials such as coal gangue, fly ash, and cement. The results prove that the strengths of the test ratios can meet the strength design criteria and lay the foundation for the requirements of similar simulation experiments. In order to study the characteristics of overburden failure, stress and displacement in the process of filling mining, the key technical parameters of overburden movement are determined. Similar simulation experiments were conducted to study the movement and deformation of overburden rock and the displacement and stress distribution law of overburden rock in the coal mine under different filling rates and filling steps conditions. The results show that the filling rate and filling step are the keys to preventing the overlying rock from rupture and collapse, and the larger the filling rate is, the smaller the stress and displacement of the overburden; the larger the filling step is, the larger the displacement and stress change of the overburden, and vice versa. In addition, the displacement curve along the strike is basically an "arch" type distribution, and the stress variation trend is "large-small-large" with a "Z" type distribution. The research results are of great significance to guide the practice of filling mining and can provide the theoretical basis for its further promotion.

Study on hard rock particle size division based on Mars rover traction performance

To simplify the dynamic solution of the contact between the rigid wheel of Mars rover and the spherical hard stone on the mixed terrain, a model for hard stone particle size division based on the traction performance of Mars rover is proposed. On the mixed terrain of hard rock and soft soil, the movement of hard rock will affect the traction performance of the rigid wheels of Mars rover. According to the different effects of the hard stones on the traction performance of rigid wheels, stones are divided into three types. The static sinkage of rigid wheels is calculated according to the Bekker bearing model, and the calculation formula of sliding sinkage of rigid wheels and hard stone sinkage is proposed. The type of hard stones is determined by comparing the sinkage of hard stones and rigid wheels. Finally, three kinds of hard stones with slip ratios of 0.2, 0.5, and 0.7 were substituted into the single wheel simulation platform and the soil trough experiment platform for simulation and experiment. The results show that on mixed terrain, the error of simulation and experimental results of fixed hard stones under three slip rates is below 5.4%, the error of drawbar pull in simulation and experimental results of movable hard stones is above 126%, and the error of simulation and experimental results of scattered small hard stones is below 2%, which verifies the effectiveness of the hard stone particle size division model.