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Revisiting the theoretical prediction of the explosive performance found by the Trauzl test

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Defence Technology（防务技术） 2024年第6期36卷 163-174页

作者： Ivana Dobrilovic Mario Dobrilovic Muhamed Suceska Faculty of mining Geology and Petroleum EngineeringDepartment of Mining Engineering and GeotechnicsUniversity of ZagrebPierottijeva 6Zagreb10000Croatia

The Trauzl lead block test allows the determination of the approximate performance of explosives in blasting applications by measuring the volume increase(expansion)that is produced by the detonation of an explosive charge in the cavity of a lead *** this paper,we reconsider the possibility of interpreting the Trauzl test results in terms of detonation parameters or *** detonation parameters used in the analysis are calculated using the thermochemical code EXPLO5,while the hydrocode AUTODYN is used to simulate the effect of explosive charge density and reaction rate on the results of the Trauzl *** increase in the volume of the lead block cavity was found to correlate best with the product of the detonation heat and the root of the volume of detonation *** simulation showed that the density of explosive charge and the rate of explosive decomposition affect the dynamics of the interaction of the detonation product and the lead block,and consequently the lead block cavity volume increase.

关键词： Trauzl lead block test Performance of explosives EXPLO5 AUTODYN Detonation heat

Effect of non-uniform swelling on coal multiphysics during gas injection: The triangle approach

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1362-1372页

作者： Yifan Huang Jishan Liu Yaoyao Zhao Derek Elsworth Yee-Kwong Leong department of Chemical Engineering School of EngineeringThe University of Western Australia35 Stirling HighwayWA 6009Australia State Key Laboratory of Coal Resources & Safe mining China University of Mining& TechnologyBeijing100803China department of Energy and mineral Engineering G3 Centre and Energy InstituteThe Pennsylvania State UniversityUniversity ParkPA16802USA

In current dual porosity/permeability models,there exists a fundamental assumption that the adsorption-induced swelling is distributed uniformly within the representative elementary volume (REV),irrespective of its internal structures and transient ***,both internal structures and transient processes can lead to the non-uniform *** this study,we hypothesize that the non-uniform swelling is responsible for why coal permeability in experimental measurements is not only controlled by the effective stress but also is affected by the adsorption-induced *** propose a concept of the swelling triangle composed of swelling paths to characterize the evolution of the non-uniform swelling and serve as a core link in coupled multiphysics.A swelling path is determined by a dimensionless volumetric ratio and a dimensionless swelling *** swelling paths have the same start and end point,and each swelling path represents a unique swelling *** swelling path as the diagonal of the triangle represents the case of the uniform swelling while that as the two perpendicular boundaries represents the case of the localized *** paths of all intermediate cases populate inside the *** corresponding relations between the swelling path and the response of coal multiphysics are established by a non-uniform swelling *** define this method as the triangle approach and corresponding models as swelling path-based *** proposed concept and models are verified against a long-term experimental measurement of permeability and strains under constant effective *** results demonstrate that during gas injection,coal multiphysics responses have a close dependence on the swelling path,and that in both future experiments and field predictions,this dependence must be considered.

关键词： Transient process Heterogeneity Swelling triangle Swelling path Non-uniform swelling coefficient

Three-dimensional Modeling of Ore-forming Elements and mineralization Prognosis for the Yechangping Mo Deposit,Henan Province,China

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 736-752页

作者： DING Gaoming JI Genyuan YAN Guolong XU Yongzhong WANG Kunming XIAO Chun WANG Quanle GUO Dongbao China National Administration of Coal Geology Beijing 100038China MNR Key Laboratory of Metallogeny and mineral Assessment Institute of Mineral ResourcesCAGSBeijing 100037China China Gold Group Geological Co. Ltd.Beijing 100011China China Gold Group ZhongYuan mining Co. Ltd.SanmenxiaHenan 472000China Lanzhou mineral Exploration Institute of Gansu Nonferrous Metal Geological Exploration Bureau Lanzhou 730046China

Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep *** approach provides key information for the quantitative prediction of deep mineral localization,three-dimensional fine interpolation,analysis of spatial distribution patterns,and extraction of quantitative mineral-seeking *** Yechangping molybdenum(Mo)deposit is a significant and extensive porphyry-skarn deposit in the East Qinling-Dabie Mo polymetallic metallogenic belt at the southern margin of the North China *** borehole data on oreforming elements underpin deep geochemical *** methodology includes the following steps:(1)Threedimensional geological modeling of the deposit was established.(2)Correlation,cluster,and factor analyses post delineation of mineralization stages and determination of mineral generation sequence to identify(Cu,Pb,Zn,Ag)and(Mo,W,mfe)assemblages.(3)A three-dimensional geochemical block model was constructed for Mo,W,mfe,Cu,Zn,Pb,and Ag using the ordinary kriging method,and the variational function was developed.(4)Spatial distribution and enrichment characteristics analysis of ore-forming elements are performed to extract geological information,employing the variogram and w(Cu+Pb+Zn+Ag)/w(Mo+W)as predictive indicators.(5)Identifying the western,northwestern,and southwestern areas of the mine with limited mineralization potential,contrasted by the northeastern and southeastern areas favorable for mineral exploration.

关键词： 3D geochemical model ore-forming elements geostatistics deep mineralization prediction Yechangping Mo deposit

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Determination of critical state line(CSL)for silty-sandy iron ore tailings subjected to low-high confining pressures

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1684-1695页

作者： Nilo Cesar Consoli João Vítor de Azambuja Carvalho Alexia Cindy Wagner Hugo Carlos Scheuermann Filho Inácio Carvalho Pedro Pazzoto Cacciari João Paulo de Sousa Silva Civil Engineering Universidade Federal do Rio Grande do SulPorto AlegreRS90035-190Brazil Exploration and mineral Projects-mineral Development Centre VALE S.A.Santa LuziaMG33040-900Brazil department of Civil Geological and Mining EngineeringPolytechnique MontrealQuebecH3C 3A7Canada

The disposal of filtered tailings in high dry stacks can induce particle breakage,changing the material's behaviour during the structure's *** grading changes influence material properties at the critical state,and this is not mature for intermediate artificial soils(tailings)in a broad range of confining *** this paper,it aims to describe the behaviour of iron ore tailings in a spectrum of confining pressures broader than the reported in previous studies.A series of consolidated drained(CD)triaxial tests was carried out with confining pressures ranging from 0.075 MPa to 120 *** results show that the amount of breakage plays an essential role in the response of iron ore *** existence of curved critical state line(CSL)in both specific volume(ν)-logarithm of mean effective stress(p′)and deviatoric stress(q)-mean effective stress(p′)planes,and different responses in the deviatoric stress-axial strain-volumetric strain curves were *** inverse S-shaped equation was proposed to represent the silty-sandy tailings'behaviour up to high pressures onν-lnp′*** proposed equation provides a basis for enhancing constitutive models and considers the evolution of the grading up to severe loading *** adjustment considered three regions with different responses associated with particle breakage at different pressure levels.

关键词： Tailings Iron ore tailings dry stacking Silty-sandy material Critical state soil mechanics High confining pressures Particle breakage

Numerical modelling of post-failure behaviors of coal specimens

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 514-531页

作者： Ajeet Yadav Bhaskara Behera Gauri Shankar Prasad Singh Sanjay Kumar Sharma department of mining Engineering Indian Institute of Technology(Banaras Hindu University)VaranasiUttar Pradesh221005India

A modelling approach consisting of best-fit relations to estimate the post-yield strength parameters is presented for simulating post-peak behavior beyond the point of residual strength of coal pillars having different w/h *** model was developed based on back-analysis of the complete stress-strain behavior of specimens belonging to six different Indian coal seams with different w/h ratios of 0.5 *** was found that the simultaneous degradation of the cohesion and friction angle of the Mohr-Coulomb rock material characterizes the post-peak strength behavior of the *** resulting expressions are simplistic as they require parameters that can be easily determined using uniaxial and triaxial compression ***,the developed model was validated by simulating the triaxial tests of coal specimens with different sizes under varying confining stresses and comparing its findings with the published test *** study showed that its implementation in the numerical model could reproduce laboratory-observed mechanical response,deformation behavior,and failure mechanism very closely.

关键词： Strain softening Dilatancy Interface Shape effect Residual strength

Study on creep deformation and energy development of underground surrounding rock under four‐dimensional support

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Deep Underground Science and Engineering 2024年第1期3卷 25-38页

作者： Zhanguo Ma Junyu Sun Peng Gong Pengfei Yan Nan Cui Ruichong Zhang School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhouChina State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhouChina department of mining Engineering Colorado School of MinesGoldenUSA

There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground *** previously proposed four‐dimensional support(hereinafter 4D support),as a new support technology,can set the roadway surrounding rock under three‐dimensional pressure in the new balanced structure,and prevent instability of surrounding rock in underground ***,the influence of roadway depth and creep deformation on the surrounding rock supported by 4D support is still *** study investigated the influence of roadway depth and creep deformation time on the instability of surrounding rock by analyzing the energy *** elastic strain energy was analyzed using the program redeveloped in *** numerical simulation results indicate that the combined support mode of 4D roof supports and conventional side supports is highly applicable to the stability control of surrounding rock with a roadway depth exceeding 520 *** the increase of roadway depth,4D support can effectively restrain the area and depth of plastic deformation in the surrounding ***,4D support limits the accumulation range and rate of elastic strain energy as the creep deformation time increases.4D support can effectively reduce the plastic deformation of roadway surrounding rock and maintain the stability for a long deformation period of 6 *** confirmed by in situ monitoring results,4D support is more effective for the long‐term stability control of surrounding rock than conventional support.

关键词： coal mines elastic strain energy four‐dimensional support large roadway depth long‐term stability control plastic deformation surrounding rock

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A Comparative Study of Two Tree-Based Models for Predicting Flyrock Velocity at Open Pit Bench mining

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Open Journal of Applied Sciences 2024年第2期14卷 267-287页

作者： Ezatullah Rawnaq Bassir Esmatyar Akihiro Hamanaka Takashi Sasaoka Hideki Shimada department of Earth Resources Engineering Kyushu University Fukuoka Japan department of mining and mineral Engineering Suleyman Demirel University Isparta Türkiye

Blasting is a cost-effective technique to break hard rock volumes by using explosives in the mining and civil engineering realms. Moreover, although blasting is a designed process and plays an indispensable role in these industries, it can also have multiple adverse environmental impacts. One such effect is flyrock, which poses risks to nearby machinery, and residential structures, and can even lead to injuries or fatalities. To optimize blasting efficiency as well as restrict side effects, prediction of the blast aftereffects is vital. Therefore, the present work focuses on using two machine learning methods to predict the velocity of flyrock in the open pit mine. To address this issue, a comprehensive dataset was gathered from the open pit mine. Then, Decision Tree and Random Forest algorithms were employed to predict flyrock velocity. The Random Forest model demonstrated superior performance compared to the Decision Tree model. Nonetheless, the performance of the Decision Tree model was deemed satisfactory, as evidenced by its coefficient of determination value of 0.83, mean squared error (MSE) of 4.2, and mean absolute percentage error (MAPE) of 5.6%. Considering these metrics, it is reasonable to conclude that tree-based algorithms can be effective in predicting flyrock velocity.

关键词： Flyrock Machine Learning Bench Blasting Coefficient of Determination

Numerical analysis of moving train induced vibrations on tunnel,surrounding ground and structure

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 179-192页

作者： Swati Srivastav Sowmiya Chawla Swapnil Mishra department of Applied Geophysics Indian Institute of Technology(ISM)Dhanbad 826004India department of Civil Engineering Indian Institute of Technology(ISM)Dhanbad 826004India department of mining Engineering Indian Institute of Technology(ISM)Dhanbad 826004India

This study is focused on the effect of vibration induced by moving trains in tunnels on the surrounding ground and structures.A three-dimensional finite element model is established for a one-track railway tunnel and an adjacent twelve-storey building frame by using commercial software Midas GTS-NX(2019)and Midas *** study considered the moving load effect of a complete train,which varies with space as well as with *** effect of factors such as train speed,overburden pressure on the tunnel and variation in soil properties are studied in the time *** a result,the variations in horizontal and vertical acceleration for two different sites,i.e.,the free ground surface(without structure)and the area containing the structure,are ***,the displacement pattern of the raft foundation is plotted for different train *** lower speeds,the heaving phenomenon is negligible,but as the speed increases,both the heaving and differential settlement increase in the *** study demonstrates that the effect of moving train vibrations should be considered in the design of new nearby structures and proper ground improvement should be considered for existing structures.

关键词： moving train load tunnels vibration effect finite element method(FEM) wave propagation

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Multi-Dimensional QoS Evaluation and Optimization of Mobile Edge Computing for IoT:A Survey

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Chinese Journal of Electronics 2024年第4期33卷 859-874页

作者： Jiwei HUANG Fangzheng LIU Jianbing ZHANG Beijing Key Laboratory of Petroleum Data mining China University of Petroleum department of Computer Science and Technology China University of Petroleum

With the evolvement of the Internet of things(IoT), mobile edge computing(MEC) has emerged as a promising computing paradigm to support IoT data analysis and processing. In MEC for IoT, the differentiated requirements on quality of service(QoS) have been growing rapidly, making QoS a multi-dimensional concept including several attributes, such as performance, dependability, energy efficiency, and economic factors. To guarantee the QoS of IoT applications, theories and techniques of multi-dimensional QoS evaluation and optimization have become important theoretical foundations and supporting technologies for the research and application of MEC for IoT,which have attracted significant attention from both academia and industry. This paper aims to survey the existing studies on multi-dimensional QoS evaluation and optimization of MEC for IoT, and provide insights and guidance for future research in this field. This paper summarizes the multi-dimensional and multi-attribute QoS metrics in Io T scenarios, and then several QoS evaluation methods are presented. For QoS optimization, the main research problems in this field are summarized, and optimization models as well as their corresponding solutions are elaborated. We take notice of the booming of edge intelligence in artificial intelligence-empowered Io T scenarios, and illustrate the new research topics and the state-of-the-art approaches related to QoS evaluation and optimization. We discuss the challenges and future research directions.

关键词： Internet of things Mobile edge computing Quality of service Quality of service evaluation Quality of service optimization PERFORMANCE EVALUATION RESOURCE-ALLOCATION SERVICE MIGRATION DELAY CLOUD DEPENDABILITY MECHANISM INTERNET SYSTEM THINGS