Mining Rock Mass Research Articles

Characteristics and Mechanical Mechanism of In Situ Unloading Damage and Core Discing in Deep Rock Mass of Metal Mine

Based on the phenomena of core damage and core discing in deep strata of metal mines in Laizhou area, the physical and mechanical mechanism behind these phenomena and characteristics is discussed. The analysis shows that the damage effect of deep high stress rock is obvious after in-situ unloading, the core discing occurs when the damage reaches a certain degree, and the time effect of damage increases with the increase of buried depth. The characteristics of core discing are closely related to the stress environment and the mesostructure and mineral composition of the rock. Monzogranite with a large particle size and high content of potassium feldspar is easier to occur core discing than granodiorite in this area. The mechanism of core discing in Sanshandao gold mine is as follows: tensile failure occurs in the middle of the core, and composite failure of shear and tension occurs at the edge. The crack extends from the middle of the core to the outer edge, and finally, the tensile crack and shear crack intersect and connect to form a cake crack. Considering the stress condition and strength conditions of core discing, the energy release rate of rock mass in the core discing area is large, which has the conditions for strong rock burst. In addition, the ratio of maximum stress to tensile strength at the starting position of core discing is about 6.5 in this area, which is consistent with the previous analysis, so as to provide a strong basis for calculating in-situ stress based on the core discing phenomenon.

Fractal Study on the Failure Evolution of Concrete Material with Single Flaw Based on DIP Technique

Crack inclination and material heterogeneity have important effects on the meso-mechanical mechanism and macroscopic mechanical behavior of rock-like materials. In order to study the failure characteristics of shotcrete body during the process of using shotcrete bolt mesh support in the deep fractured rock mass of Lannigou Gold Mine, this paper combined the Digital Image Processing Technique (DIP) and RFPA2D (Rock Failure Process Analysis System) to establish a real meso-structure numerical model of concrete with different inclination angle cracks, simulating its crack propagation law and failure process, and studied the influence of crack geometry distribution and meso-heterogeneity on the effect of concrete structure. The findings reveal that the crack inclination angle has a substantial impact on concrete materials' compressive strength and elastic modulus, and both of them all show a nonlinear increase with the increase of crack angle; Because of the inhomogeneity of the materials, the inclination and propagation pathways of wing cracks are random, and the aggregate inhibits crack initiation and propagation. The wing crack's initiation position moves closer to the tip as the crack inclination angle increases, and the length gets shorter; Acoustic emission(AE) evolution characteristics are similar in samples with varying dip angles. In the early stages of loading, the AE energy is minimal, and increases rapidly when approaching the peak stress. The fractal dimension was used to describe the damage evolution process inside the material, and a damage variable index (ω) based on the fractal theory was proposed. The more the ω, the greater the material's degree of degradation. The proposed index provided a new method for quantitative study of the damage evolution characteristics of rock-like materials. It has guiding significance for the research on the stability of wet shotcrete in the deep fractured rock mass of Lannigou Gold Mine.

Cross-related microseismic location based on improved particle swarm optimization and the double-difference location method of jointed coal rock mass

The location algorithm is the core of microseismic monitoring, and the location results directly influence the effectiveness of the subsequent source analysis. We introduced the double-difference (DD) location method in seismic location into microseismic monitoring. We built a travel time equation of the layered velocity model using the ray-tracing theory and analyzed the waveform cross-correlation of the microseismic data using a generalized cross-correlation (GCC) technique. The improved particle swarm algorithm was successfully conducted to improve the randomness of the initial location. We then adopted the DD location method to precisely locate the secondary location, and it showed better location accuracy and computational efficiency than that by a traditional location algorithm based on the simplified geological model. The theoretical simulation and practice results in deep mining show that the proposed method significantly increased the location accuracy, and the results were concentrated and consistent with the field results. Moreover, we verified the importance of the velocity model for location accuracy. This algorithm also increased the ease of identifying fracture regions, providing the necessary theoretical and technical support for the source location of the jointed coal rock mass in deep mining.

Predicting rock displacement in underground mines using improved machine learning-based models

Displacement of rock mass in tunnels and underground mines is considered one of the most hazardous phenomena that can cause the collapse of the structures. In this study, the rock properties, such as the depth of the tunnels (H), the angle of rock layers (α), anti-bending moment (Wc), the width of the tunnels (b), the tensile strength of rock layers (Rn), and monitoring distance (Lb), and observation time (t), were investigated to predict rock displacement in tunnels and underground mines. Two novel soft computing models, namely Harris Hawks optimization algorithm (HHOA)-based support vector machine (SVM) model (i.e., HHOA-SVM) and Grasshopper optimization algorithm (GOA)-based SVM model (i.e., GOA-SVM), were developed for this aim based on the field measurements. A total of 12 measurement stations and 63 observations of vertical rock mass displacement, rock properties, and observation time in some underground coal mines in the Donbas region (Ukraine) were compiled as the dataset for developing soft computing models. In addition, a constraint was also added to the proposed HHOA-SVM and GOA-SVM models to prevent the model from offering negative results in predicting rock displacement. The conventional models, such as SVM (without optimization) and artificial neural network (ANN), were also investigated to compare favorably with the two proposed HHOA-SVM and GOA-SVM models. Furthermore, linear and nonlinear equations were also established to predict rock displacement and compared to the soft computing models. The results showed that the novel HHOA-SVM and GOA-SVM models provided better performances than conventional SVM and ANN models. Besides, the sensitivity of the input variables was also analyzed to discover the certain characteristics of the rock displacement phenomenon through the properties of rock and observation time. The findings show that H, Lb, t, and α are the most influential parameters for predicting rock displacement in tunnels and underground mines. In contrast, the contribution of b in rock displacement is tiny, and Wc did not relate to the rock displacement in tunnels and underground mines.

Analysis of Mining Crack Evolution in Deep Floor Rock Mass with Fault

To further explore the crack evolution of floor rock mass, the mechanism of fault activation, and water inrush, this paper analyzes the crack initiation and propagation mechanism of floor rock mass and obtains the initiation criteria of shear cracks, layered cracks, and vertical tension cracks. With the help of simulation software, the process of fault activation and crack evolution under different fault drop and dip angles was studied. The results show that the sequence of crack presented in the mining rock mass is vertical tension cracks, shear cracks, and layered cracks. The initiation and propagation of the shear cracks at the coal wall promote the fault activation, which tends to be easily caused at a specific inclination angle between 45° and 75°. The fault drop has no obvious impact on the evolution of floor rock cracks and will not induce fault activation. However, the increase of the drop will cause the roof to collapse, reducing the possibility of water inrush disaster. Research shows that measures such as adopting improved mining technology, reducing mining disturbance, increasing coal pillar size, and grouting before mining as reinforcement and artificial forced roof can effectively prevent water inrush disasters caused by deep mining due to fault activation.

Simulating hydraulic fracturing preconditioning in mines with the material point method

Hydraulic Fracturing (HF) is becoming increasingly popular as a candidate mechanism for preconditioning rock mass in mining. To date, accurate numerical methods for simulating the complex behaviour of fluid-driven fracture network near excavations are not well established within the mining industry. In this work we propose a novel implementation of the Material Point Method (MPM) to simulate the complex HF sequence followed in mining; this creates a dense network of fractures. We present a new way of generating fractures in the context of the MPM framework by incorporating the so-called Marching Cubes algorithm into the computational background grid. We first validate our model against some laboratory verified results and then apply the method to some conceptual models. These experiments illustrate effective ways of preconditioning with HF to ensure that stress is modified around the fractured area and the associated seismic hazard thereby reduced.

Research on the Redistribution Law of Lateral Mining Stress and the Bearing Characteristics of Section Coal Pillar in Extra-Thick Fully Mechanized Top-Coal Caving Mining

Due to the change of ground stress environment caused by underground coal mining, the intense lateral mining stress concentration is formed around the stope; so section coal pillar is generally set up to bear the mining pressure, but the different sizes of coal pillars have obvious influence on the bearing capacity of those pillars and the characteristics of mining pressure. Mastering the mechanism characteristics by which coal pillars bearing capacity and mining stress distribution is crucial to identify the reasonable coal pillar size and give full play to the bearing role of section coal pillar, given their importance for the safety and bearing stability of engineering rock mass in underground coal mining. Therefore, the bearing characteristics of section coal pillar and the redistribution of mining stress are achieved with a mechanical model analysis on the basis of the analysis of coal pillar bearing and mining influence characteristics. Moreover, applying the elastic-plastic mechanics theory revealed the mechanical equations of the effective bearing size of coal pillar and redistribution of mining stress in longwall face. Combined with the analysis of a specific engineering example, the research results are as follows. During a roadway excavation, the continuous mining stress transfer occurs “stress redistribution” and the mechanical failure of bearing coal pillar consists of lateral mining and roadway side failures. The bearing coal pillar has two critical dimensions (i.e., the critical dimension W e of the self-bearing stability coal pillar and the critical dimension W p of failure through the coal pillar). The mechanical state of the lateral mining stress redistribution and bearing coal pillar is divided into the three situations: ① when the width of coal pillar W < W p , only one stress concentration area exists, the bearing capacity of the coal pillar is invalid at this stage, and the lateral mining stress concentration transfers to the roadway solid coal side; ② when the width of the coal pillar W e ≥ W ≥ W p , two stress concentration areas appear at this stage, and the coal pillar is in the critical state of self-bearing stability; ③ when the width of the coal pillar W > W e , three stress concentration areas are present, and the coal pillar at this stage is in a self-bearing stable state. Among all these factors, only the size of coal pillar is completely controllable, so the aspects of safe bearing and reserved size design of coal pillar, after estimating the critical size of coal pillar, the coal pillar size design is carried out according to the mine pressure control needs of mining engineering, and the cohesion, internal friction angle, interlayer friction coefficient, and coal seam mining height are improved by artificial technology, so as to realize the resource safe and efficient mining of all kinds of coal seam mining conditions; in the calculation of wide coal pillar size, the advance mining stress concentration at the end of the self-working face should be taken as the mining load condition, and the reserved size meets the condition of W > W e , thereby ensuring the stable bearing of the wide coal pillar despite the advanced mining stress concentration during the self-working face mining; in the calculation of narrow coal pillar size, the lateral mining stress concentration before mining should be taken as the mining load condition and the reserved size meets the condition W < W p , thereby realizing the effective transfer of mining stress concentration to the roadway solid coal side.

Characteristics Analysis of Generalized Rock Quality Designation (RQD) Based on Degree of Joint Development

Rock quality designation (RQD) is widely adopted as a fundamental tool in characterizing rock masses since it was devised in 1964. Since the conventional RQD calculation is limited due to its dependence on the selected threshold, previous research introduced generalized RQD to adequately reflect the anisotropy and scale effect of RQD. However, the influence of the joint development inside rock mass on generalized RQD remains unclear. The objective of this work is to investigate characteristics of the generalized RQD in view of different development degrees of discontinuities in rock mass, including spacing (density) and trace length. Three-dimensional fracture network modelling is employed to simulate the actual rock mass of open-pit iron mine in China. Virtual scanlines are set to obtain RQD values in different directions. The results primarily show that the generalized RQD should be introduced to calculate the RQD with different thresholds to fully reflect the anisotropy of rock mass. The optimal threshold can be obtained based on an anisotropic coefficient, which is defined by (RQDmax-RQDmin). It is also indicated that the fracture spacing has a great influence on both the anisotropy of RQD and the selection of the optimal threshold. The optimal threshold of the generalized RQD increases with the increase in the fracture spacing. In addition, the scale effect of RQD in different models is discussed by changing the length of the scanlines. The longer the scanlines we set, the more stable RQD value can be obtained in the model. It is recommended to fit much longer scanline to get realistic RQD in heavily fractured rock mass.

Geomechanical characterization of a heterogenous rock mass using geological and laboratory test results: a case study of the Niobec Mine, Quebec (Canada)

To conduct a successful geomechanical characterization of rock masses, an appropriate interpretation of lithological heterogeneity should be attained by considering both the geological and geomechanical data. In order to clarify the reliability and applicability of geological surveys for rock mechanics purposes, a geomechanical characterization study is conducted on the heterogeneous rock mass of Niobec Mine (Quebec, Canada), by considering the characteristics of its various identified lithological units. The results of previous field and laboratory test campaigns were used to quantify the variability associated to intact rock geomechanical parameters for the different present lithological units. The interpretation of geomechanical similarities between the lithological units resulted in determination of three main rock units (carbonatite, syenite, and carbonatite-syenite units). Geomechanical parameters of these rock units and their associated variabilities are utilized for stochastic estimation of geomechanical parameters of the heterogeneous rock mass using the Monte Carlo Simulation method. A comparison is also made between the results of probabilistic and deterministic analyses to highlight the presence of intrinsic variability associated with the heterogeneous rock mass properties. The results indicated that, for the case of Niobec Mine, the carbonatite-syenite rock unit could be considered as a valid representative of the entire rock mass geology since it offers an appropriate geomechanical approximation of all the present lithological units at the mine site, in terms of both the magnitude and dispersion of the strength and deformability parameters.Article HighlightsEvaluating the reliability and applicability of geological survey outcomes for rock mechanics purposes.A geomechanical characterization study is conducted on the heterogeneous rock mass by considering the various identified rock lithotypes.The geomechanical parameters of intact units and their associated variabilities are used to stochastically estimate the geomechanical parameters of the heterogeneous rock mass by employing the Monte Carlo Simulation.A comparison is also made between the results of probabilistic and deterministic geomechanical analyses.The results indicate that, in the case of Niobec Mine, the combined syenite-carbonatite rock unit could be considered as a valid representative of the entire rock mass.

Spatio-temporal hierarchical cluster analysis of mining-induced seismicity in coal mines using Ward's minimum variance method

Mining-induced seismicity is one of the most dangerous physical phenomenon's accompanying coal and ore extraction in underground mines and often resulting in rock burst. In many cases, this seismicity can be grouped together, forming spatial clusters of events related to some structures in mines such as faults or pillars. However, as shown in this paper, the usual seismicity in coal mines is mainly related to current mining process and there are no distinct spatial or temporal groups of seismic events, but rather they form continuous cloud of events related to mining activity. Therefore, we introduce new spatio-temporal metric together with Ward's minimum variance method to obtain hierarchical clustering analysis of mining-induced seismicity. Constructing metric in this way made it possible to assess seismic hazard concurrently in space and time. The clustering method is utilized to a case study of mining-induced seismicity from coal mine with high seismic hazard and where high energy mainshock occurred. In each cluster, magnitude distribution of seismic activity is calculated, showing in some cases, a significant departure from Gutenberg-Richter distribution of seismic events, which can be important in seismic hazard analysis. As a measure of accuracy of each cluster locations we have introduced bootstrapping procedure. We have shown that location errors of seismic activity affect each cluster center location of the order of a few tens of meters. The presented cluster analysis of mining seismicity provides new measures to determine group of seismic sources and high stressed areas in the rock mass in mines allowing for determination of seismic and rockburst hazard.

Comparative study on fracture characteristics of coal and rock samples based on acoustic emission technology

Monitoring on the damage evolution process of the coal and rock mass in coal resource mining play a vital role in safe production and avoiding economic losses. This study aims at further improving effectiveness and accuracy of acoustic monitoring method in the process of coal resource mining. For this purpose, a rock mechanics testing system and an acoustic emission (AE) test system are employed to conduct AE event location experiments on the coal and rock samples under uniaxial loading. According to the basic theory of b-value and single-link cluster (SLC) method, changing trend of related parameters with stress is studied, including b-value, spatial correlation length ξ and information entropy H. Then, the reason for variation of these three parameters is revealed. The analysis results show that b-value has not obvious change at the initial stage of loading, but spatial correlation length ξ presents upward trend during this period. Compared with b-value and spatial correlation length ξ, information entropy H is not sensitive to damage state of the coal and rock sample during the most time of loading process. However, it is worth noting that that these three parameters show significant change trend before the buckling failure of the coal and rock samples. Based on three-dimensional crack growth theory and criterion of microcrack density, the research results show that the change of the parameters are the macro characterization of transformation process from small-scale microfracture to large-scale microfracture and from local damage to overall damage for the coal and rock samples subjected to uniaxial loading. This research provides a new method to evaluate the damage state of the coal and rock mass under high stress using AE source location technology, and it has important guiding significance and reference value for ensuring the safety of life and property in the process of coal resource mining.

Rock Mass Classification by Multivariate Statistical Techniques and Artificial Intelligence

This study aims to improve the quality and accuracy of RMR classification system for rock masses in open pit mines. A database of open pit mines comprising basic parameters for obtaining the RMR was used. Techniques applied in this research were multivariate statistics and artificial intelligence. In relation to multivariate statistics, factor analysis was capable of identifying underlying factors not observable in the original variables, using the variables of these factors in the classification system, instead of all RMR variables. The proposed classifier was obtained by training neural networks. The results of the factor analysis allowed the identification of three common factors. Factor 1 represents the strength and weathering of the rock mass. Factor 3 represents the fracturing degree of the rock mass. Finally Factor 2 represents water flow conditions. Thirty artificial neural networks were trained with randomly selected training samples. The trained networks proved to be effective and stable. Regarding the validation of the networks, the values obtained for the overall probability of success and apparent error rate showed normal distributions and a low dispersion rate, with average rates of 0.87 and 0.13, respectively. Regarding specific errors, error values were recorded only between contiguous RMR classes. The major contribution of the study is to present a new methodology for achieving rock mass classifications based on mathematical and statistical fundamentals, aiming at optimising the selection of variables and consequent reduction of subjectivity in the parameters and classification methods.

Numerical Simulation of Fluid-Solid Coupling in Surrounding Rock for River Stope Mining

Mining disturbance will induce further weakening of faults and rock bridges, improve rock mass permeability and, in serious cases, conduct surface rivers to cause disasters. A numerical calculation model of river-fault in the mining area is established. Based on the fluid-solid coupling theory of rock mass, the influence of mining disturbance on the development and evolution process of rock bridge rupture and river-fault-stope potential seepage channel is simulated and calculated. Research studies show that under the disturbance of ore body mining, it is possible to form a channel from the river to fault to seepage and drainage in the stope. The disturbance of ore body mining has no great adverse effect on the stability of the rock mass at the top of F2 fault. The rock mass damage caused by mining is only distributed in local areas, and the rock bridge between the river, fault, and stope is not completely connected. The fracture of mining rock mass leads to the increase in permeability of rock mass, and seepage tends to spread in the direction of the fault, but there is no obvious through drainage channel from surface water to the stope. The results of research provide technical guidance for the mine to use the filling mining method after the river does not change the road safety and reliability certification and can also provide reference for similar mines.

New approaches to the assessment of stability of rock rock arrays

When summarizing the results obtained on the stability of rock masses a discrepancy was found between the parameters of the strength properties of rock formations, determined according to existing methods and state standards, to their values under natural conditions. As a result of the studies, the degree of geomechanical knowledge of the rock mass of the Gaisky underground mine is significantly increased. Based on the numerical simulation of the stress-strain state of the ore and rock mass, the rationale for the optimal mining of reserves at a depth of -830 / -1390 m was substantiated. The main compressive stresses of the Gaisky deposit act in the sub-latitudinal direction along the axis of the chambers, creating stresses exceeding 100 MPa on their outcrops. If the compressive strength of the massif is up to 100 MPa, found by known methods, ore masses of the third stage (pillars) below the -910 m horizon should be destroyed. In assessing the stability of pillars (chamber walls) in the last 3 years, in some cases, disagreement arose. The calculated stresses exceed the maximum allowable ones, but the pillars (chamber walls) remain stable. It justifies the correction of the obtained values of the ultimate strength of rocks with correction factors and the introduction of the definition of reduced strength (227 MPa), in which the roof, walls of the chambers and pillars are in a stable state. As a result of the study, the obtained values of the stress state of the rock mass and its strength characteristics more realistically reflect the predicted destruction or stability of the rock mass at the mine. The performed studies contribute to a more justified adjustment of mining technology parameters while ensuring the safety of mining operations.

ПРОГНОЗИРОВАНИЕ ДЕФОРМАЦИЙ УСТУПОВ СКАЛЬНОГО МАССИВА КУРЖУНКУЛЬСКОГО КАРЬЕРА С ИСПОЛЬЗОВАНИЕМ КИНЕМАТИЧЕСКОГО АНАЛИЗА

ПРОГНОЗИРОВАНИЕ ДЕФОРМАЦИЙ УСТУПОВ СКАЛЬНОГО МАССИВА КУРЖУНКУЛЬСКОГО КАРЬЕРА С ИСПОЛЬЗОВАНИЕМ КИНЕМАТИЧЕСКОГО АНАЛИЗА

Study on Impact Tendency of Coal and Rock Mass Based on Different Stress Paths

With the increased mining depth, the dynamic disaster of rock burst in coal mines has become increasingly prominent, and the impact tendency of coal and rock mass in deep coal seam mining is a necessary condition for the occurrence of rock burst and an important index to measure the failure of coal and rock mass. Laboratory tests and numerical tests were used to study the impact tendency of coal and roof strata, including the deformation characteristics, failure characteristics, and bending energy index of the coal and rock mass of different sizes, the failure law and energy evolution characteristics of tlhe coal and rock mass under the same size, and the unloading characteristics of the coal and rock mass under the same size and different confining pressures. The results are shown as follows: (1) The rock roof was determined to have a weak impact tendency through the mechanical test. (2) With the increased size, the microcracks in the rock samples increased correspondingly, and the increased meso‐defect leading to the increased heterogeneity was an essential reason for the size effect. The strength of the rock mass decreased with the increased specimen size. The larger the specimen size was, the lower the bending energy index was. (3) Triaxial loading and unloading were tested for the same size under different surrounding rocks. Under the same loading conditions, with the increased confining pressure, the strength and bending energy index of rock mass increased correspondingly, and the failure of rock mass transformed from tensile to shear failure. The failure form and strength characteristic of rock under the unloading condition are different from those under the loading condition. The failure degree was intense, with a high bending energy index. Compared with the loading situation, the impact tendency caused by unloading was higher, and the dynamic impact disaster was more likely to occur.

Permeability characteristics of fractured rock mass: a case study of the Dongjiahe coal mine

The intricate distribution of fractures in rock mass leads to the anisotropy of permeability characteristics of the rock mass, which affects the overall stability of rock mass. Aiming at the water inrush from floor in the deep mining of the Dongjiahe coal mine, the distribution and development law of fractures in coal mine rock mass are determined by combining the acoustic emission information from the RFPA software and the in-site microseismic monitoring data. The representative element volume (REV) of permeability of fractured rock mass is determined by numerical simulation. The results show that: (1) As the increase of surrounding rock pressure, the permeability coefficient is decreasing, as well as the principal values of permeability. (2) Under the same surrounding rock pressure, the surrounding rock pressure has little influence on the principal directions of permeability; when the surrounding rock pressure is different, the principal directions of permeability changes greatly with the change of surrounding rock pressure. (3) With the increase of the trace length, the principal values of permeability dramatically increase and the size of REV gradually decreases. When the trace length reaches a certain size, the influence on the REV can be ignored.

Estimation of REV for fractured rock masses based on Geological Strength Index

The representative elementary volume (REV) of fractured rock masses is a significant index to investigate the rock mass behaviors in the continuum mechanics. In this research, a new indicator to estimate the REV size of fractured rock masses based on the Geological Strength Index (GSI) is proposed. For this purpose, a new method that combines the PFC-based synthetic rock mass (SRM) model with the Hoek-Brown (HB) failure criterion is proposed to investigate the strength and deformation properties of fractured rock masses under biaxial stress conditions. Extensive numerical analyses are carried out to estimate variation of the uniaxial compression strength (UCS), deformation modulus (E) and GSI of the Brunswick mine rock mass with increasing the size of the SRM models up to a REV size. Results show that the GSI-based indicator gives relatively larger REV size compared with the traditional UCS or deformation modulus (E) based indicators. Compared with the traditional indicators, the proposed GSI-based indicator has merits of not only reflecting the geometrical characteristics of rock structures but also containing both geometrical and mechanical properties of discontinuities.

Prediction of Vibration Velocity Generated in Mine Blasting Using Support Vector Regression Improved by Optimization Algorithms

Ground vibration generated from blasting is a detrimental side effect of the use of explosives to break the rock mass in mines. Therefore, accurately predicting ground vibration is a practical need, especially for safety issues. This research proposes hybrid artificial intelligence schemes for predicting ground vibration. The approaches are based on support vector regression (SVR) optimized with firefly algorithm (FFA), genetic algorithm (GA), and particle swarm optimization (PSO). Additionally, a hybrid FFA and artificial neural network (ANN) model and several well-known empirical models were also employed in this study. In the predictive modeling process, 90 sets of data, collected from two quarry mines in Iran, divided into two datasets, namely a training dataset and a testing dataset, were used. After model development, to provide an objective assessment of the predictive model performances, their results were compared based on several well-known and popular statistical criteria. FFA-SVR exhibits much more efficiency and reliability than PSO-SVR, GA-SVR, FFA–ANN models in terms of ground vibration prediction, indicating the superiority of FFA over PSO and GA in the SVR training.

Mathematical modeling and fuzzy approach for disaster analysis on geo-spatial rock mass in open-pit mining

Due to the complex nature of open-pit mining rock mass, multiple variables has a significant impact on slope stability, which is difficult to evaluate under disaster conditions. The damaged rock slope stability analysis using fundamental fuzzy model is established using the concept of fuzzy measurements upon the basis of statistical analysis on large amount of measured data in Geo-Spatial study. Because of the marked “fuzziness” of the variables is analyzed in this research, the slope stability issues under disaster conditions has been analyzed using Fuzzy Mathematical Theory (FMT) which examines damaged rock slope deformation failure at the open-pit mining. The fuzzy probability formula for rock mass deformation failure, and a numerical method for calculating the fuzzy probability, is derived by applying the theory of variation probability measurements in open pit mining. Here the damaged rock slope under disaster conditions in open-pit mine area has been analyzed and The fuzzy based disaster data management concept has been proposed for analyzing the disaster in open-pit mine area for the damaged rock due to disasters. Finally, the formulation of the Gauss–Legendre is a three-point technical illustration of damaged rock slope which has been used in the open pit. The practical calculation demonstrates that the technique is used for evaluating the slope stability problems in the metal mine opencast under disaster conditions.