International Journal of Mining Science and Technology最新文献

{"title":"A surrogate model for estimating rock stress by a hollow inclusion strain cell in a three-layer medium","authors":"Changkun Qin,&nbsp;Wusheng Zhao,&nbsp;Weizhong Chen,&nbsp;Peiyao Xie,&nbsp;Shuai Zhou","doi":"10.1016/j.ijmst.2025.02.003","DOIUrl":"10.1016/j.ijmst.2025.02.003","url":null,"abstract":"<div><div>Accurate acquisition of the rock stress is crucial for various rock engineering applications. The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress. This technique calculates the stress tensor by measuring strain using an HI strain cell. However, existing analytical solutions for stress calculation based on an HI strain cell in a double-layer medium are not applicable when an HI strain cell is used in a three-layer medium, leading to erroneous stress calculations. To address this issue, this paper presents a method for calculating stress tensors in a three-layer medium using numerical simulations, specifically by obtaining a constitutive matrix that relates strain measurements to stress tensors in a three-layer medium. Furthermore, using Latin hypercube sampling (LHS) and orthogonal experimental design strategies, 764 groups of numerical models encompassing various stress measurement scenarios have been established and calculated using FLAC^3D software. Finally, a surrogate model based on artificial neural network (ANN) was developed to predict constitutive matrices, achieving a goodness of fit (<em>R</em>²) of 0.999 and a mean squared error (MSE) of 1.254. A software program has been developed from this surrogate model for ease of use in practical engineering applications. The method’s accuracy was verified through numerical simulations, analytical solution and laboratory experiment, demonstrating its effectiveness in calculating stress in a three-layer medium. The surrogate model was applied to calculate mining-induced stress in the roadway roof rock of a coal mine, a typical case for stress measurement in a three-layer medium. Errors in stress calculations arising from the use of existing analytical solutions were corrected. The study also highlights the significant errors associated with using double-layer analytical solutions in a three-layer medium, which could lead to inappropriate engineering design.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 363-381"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Borehole reinforcement based on polymer materials induced by liquid-gas phase transition in simulating lunar coring","authors":"Dingqiang Mo ,&nbsp;Tao Liu ,&nbsp;Zhiyu Zhao ,&nbsp;Liangyu Zhu ,&nbsp;Dongsheng Yang ,&nbsp;Yifan Wu ,&nbsp;Cheng Lan ,&nbsp;Wenchuan Jiang ,&nbsp;Heping Xie","doi":"10.1016/j.ijmst.2025.02.001","DOIUrl":"10.1016/j.ijmst.2025.02.001","url":null,"abstract":"<div><div>Lunar core samples are the key materials for accurately assessing and developing lunar resources. However, the difficulty of maintaining borehole stability in the lunar coring process limits the depth of lunar coring. Here, a strategy of using a reinforcement fluid that undergoes a phase transition spontaneously in a vacuum environment to reinforce the borehole is proposed. Based on this strategy, a reinforcement liquid suitable for a wide temperature range and a high vacuum environment was developed. A feasibility study on reinforcing the borehole with the reinforcement liquid was carried out, and it is found that the cohesion of the simulated lunar soil can be increased from 2 to 800 kPa after using the reinforcement liquid. Further, a series of coring experiments are conducted using a self-developed high vacuum (vacuum degree of 5 Pa) and low-temperature (between −30 and 50 ℃) simulation platform. It is confirmed that the high-boiling-point reinforcement liquid pre-placed in the drill pipe can be released spontaneously during the drilling process and finally complete the reinforcement of the borehole. The reinforcement effect of the borehole is better when the solute concentration is between 0.15 and 0.25 g/mL.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 383-398"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Propagation criterion of hydraulic fracture in rock based on the rock micro-cracking mechanism","authors":"Qingwang Cai ,&nbsp;Bingxiang Huang ,&nbsp;Xinglong Zhao ,&nbsp;Yuekun Xing","doi":"10.1016/j.ijmst.2025.01.006","DOIUrl":"10.1016/j.ijmst.2025.01.006","url":null,"abstract":"<div><div>Hydraulic fracture (HF) formed in rock significantly helps with the development of geo-energy and geo-resources. The HF formation condition was challenging to understand, with obscure rock micro-cracking mechanisms being a key factor. The rock micro-cracking mechanism under gradient pore water pressure was analyzed on the scale of mineral particles and it was combined with macroscopic boundary conditions of rock hydraulic fracturing, obtaining the propagation criterion of HF in rock based on the rock micro-cracking mechanism which was verified by experiment. The results show that the disturbed skeleton stress induced by the disturbance of gradient pore water pressure in rock equals the pore water pressure difference. The overall range of the defined mechanical shape factor <em>a</em>/<em>b</em> is around 1, but greater than 0.5. Under the combined influence of pore water pressure differences and macroscopic boundary stresses on the rock micro-cracking, micro-cracks form among rock mineral particles, micro-cracks connect to form micro-hydraulic fracture surfaces, and micro-hydraulic fracture surfaces open to form macro-hydraulic fractures. HF begins to form at the micro-cracking initiation pressure (MCIP), which was tested by keeping the HF tip near the initiation point. The theoretical value of MCIP calculated by the proposed propagation criterion is close to MCIP tested.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 433-449"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental insights into anchorage performance of en-echelon joints under cyclic shear loading","authors":"Bin Wang ,&nbsp;Qiangyong Zhang ,&nbsp;Yujing Jiang ,&nbsp;Kang Duan ,&nbsp;Hongbin Chen","doi":"10.1016/j.ijmst.2025.02.006","DOIUrl":"10.1016/j.ijmst.2025.02.006","url":null,"abstract":"<div><div>Understanding the anchorage performance of en-echelon joints under cyclic shear loading is crucial for optimizing support strategies in jointed rock masses. This study examines the anchorage effects on en-echelon joints with various orientations using laboratory cyclic shear tests. By comparing unbolted and bolted en-echelon joints, we analyze shear zone damage, shear properties, dilatancy, energy absorption, and acoustic emission characteristics to evaluate anchoring effects across shear cycles and joint orientations. Results reveal that bolted en-echelon joints experience more severe shear zone damage after cycles, with bolt deformation correlating to shear zone width. Bolted en-echelon joints exhibit faster shear strength deterioration and higher cumulative strength loss compared to unbolted ones, with losses ranging from 20.04% to 72.76%. The compressibility of en-echelon joints reduces the anchoring effect during shear cycles, leading to lower shear strength of bolted en-echelon joints in later stages of shear cycles compared to unbolted ones. Bolts reinforce en-echelon joints more effectively at non-positive angles, with the best performance observed at 0° and –60°. Anchorage accelerates the transition from rolling friction to sliding friction in the shear zone, enhancing energy absorption, which is crucial for rock projects under dynamic shear loading. Additionally, rock bolts expedite the transition of the cumulative AE hits and cumulative AE energy curves from rapid to steady growth, indicating that strong bolt-rock interactions accelerate crack initiation, propagation, and energy release.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 399-416"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual-scale insights of two-phase flow in inter-cleats based on microfluidics: Interface jumps and energy dissipation","authors":"Jicheng Zhang ,&nbsp;Dawei Lv ,&nbsp;Jon Jincai Zhang ,&nbsp;Feng Wang ,&nbsp;Dawei Yin ,&nbsp;Haiyang Yu","doi":"10.1016/j.ijmst.2025.01.010","DOIUrl":"10.1016/j.ijmst.2025.01.010","url":null,"abstract":"<div><div>Cleat serves as the primary flow pathway for coalbed methane (CBM) and water. However, few studies consider the impact of local contact on two-phase flow within cleats. A visual generalized model of endogenous cleats was constructed based on microfluidics. A microscopic and mesoscopic observation technique was proposed to simultaneously capture gas–liquid interface morphology of pores and throat and the two-phase flow characteristics in entire cleat system. The local contact characteristics of cleats reduced absolute permeability, which resulted in a sharp increase in the starting pressure. The reduced gas flow capacity narrowed the co-infiltration area and decreased water saturation at the isotonic point in a hydrophilic environment. The increased local contact area of cleats weakened gas phase flow capacity and narrowed the co-infiltration area. Jumping events occurred in methane-water flow due to altered porosity caused by local contact in cleats. The distribution of residual phases changed the jumping direction on the micro-scale as well as the dominant channel on the mesoscale. Besides, jumping events caused additional energy dissipation, which was ignored in traditional two-phase flow models. This might contribute to the overestimation of relative permeability. The work provides new methods and insights for investigating unsaturated flow in complex porous media.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 451-465"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluid evolution and fragmentation characteristics under high pressure water jet impact on thermal rock","authors":"Jianming Shangguan,&nbsp;Zhaolong Ge,&nbsp;Qinglin Deng,&nbsp;Yuhuai Cui,&nbsp;Zhi Yao","doi":"10.1016/j.ijmst.2025.02.004","DOIUrl":"10.1016/j.ijmst.2025.02.004","url":null,"abstract":"<div><div>In the application of high-pressure water jet assisted breaking of deep underground rock engineering, the influence mechanism of rock temperature on the rock fragmentation process under jet action is still unclear. Therefore, the fluid evolution characteristics and rock fracture behavior during jet impingement were studied. The results indicate that the breaking process of high-temperature rock by jet impact can be divided into four stages: initial fluid-solid contact stage, intense thermal exchange stage, perforation and fracturing stage, and crack propagation and penetration stage. With the increase of rock temperature, the jet reflection angles and the time required for complete cooling of the impact surface significantly decrease, while the number of cracks and crack propagation rate significantly increase, and the rock breaking critical time is shortened by up to 34.5%. Based on numerical simulation results, it was found that the center temperature of granite at 400 °C rapidly decreased from 390 to 260 °C within 0.7 s under jet impact. In addition, a critical temperature and critical heat flux prediction model considering the staged breaking of hot rocks was established. These findings provide valuable insights to guide the water jet technology assisted deep ground hot rock excavation project.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 483-497"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two new shaped coal pillars designed to protect the subsurface pipeline in the gas-coal integrated mining field","authors":"Yixin Zhao ,&nbsp;Jiandong Ren ,&nbsp;Zhongbo Sun","doi":"10.1016/j.ijmst.2025.01.009","DOIUrl":"10.1016/j.ijmst.2025.01.009","url":null,"abstract":"<div><div>In the gas-coal integrated mining field, the conventional design method of pipeline coal pillars leads to a large amount of coal pillars being unrecovered and overlooks the pipeline’s safety requirements. Considering the coal pillar recovery rate and pipeline’s safety requirements, two new shaped coal pillar design approaches for subsurface pipelines were developed. Firstly, the deformation limitations for measuring pipeline safety are categorized into two: no deformation is permitted, and deformation is acceptable within elastic limits. Subsequently, integrating the key stratum theory (KST) and cave angle, a fishbone-shaped coal pillar design approach that does not permit pipeline deformation is established. Meanwhile, combined with the ground subsidence and the pipeline’s elastic deformation limit, a grille-shaped coal pillar design approach that accepts deformation pipelines within elastic limits is established. Those two new approaches clarify parameters including mined width, coal pillar width and mined length. Finally, the case study shows that the designed mined width, coal pillar width and mined length of the fishbone-shaped coal pillar are 90, 80, and 130 m, while those of the grille-shaped are 320, 370, and 640 m. Compared with the conventional method, the fishbone-shaped and grille-shaped coal pillar design approaches recovered coal pillar resources of 2.65×10⁶ and 5.81×10⁶ t on the premise of meeting the pipeline safety requirements, and the recovery rates increased by 20.5% and 45.0%, with expenditures representing only 56.46% and 20.02% of the respective benefits. These new approaches provide managers with diverse options for protecting pipeline safety while promoting coal pillar recovery, which is conducive to the harmonic mining of gas-coal resources.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 325-344"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructural evolution and hydraulic response of shale self-propped fracture using X-ray computed tomography and digital volume correlation","authors":"Ting Huang ,&nbsp;Cheng Zhai ,&nbsp;Ting Liu ,&nbsp;Yong Sun ,&nbsp;Hexiang Xu ,&nbsp;Yu Wang ,&nbsp;Jing Huang","doi":"10.1016/j.ijmst.2025.02.005","DOIUrl":"10.1016/j.ijmst.2025.02.005","url":null,"abstract":"<div><div>Methane in-situ explosive fracturing technology produces shale debris particles within fracture channels, enabling a self-propping effect that enhances the fracture network conductivity and long-term stability. This study employs X-ray computed tomography (CT) and digital volume correlation (DVC) to investigate the microstructural evolution and hydromechanical responses of shale self-propped fracture under varying confining pressures, highlighting the critical role of shale particles in maintaining fracture conductivity. Results indicate that the fracture aperture in the self-propped sample is significantly larger than in the unpropped sample throughout the loading process, with shale particles tending to crush rather than embedded into the matrix, thus maintaining flow pathways. As confining pressure increases, contact areas between fracture surfaces and particles expand, enhancing the system’s stability and compressive resistance. Geometric analyses show flow paths becoming increasingly concentrated and branched under high stress. This resulted in a significant reduction in connectivity, restricting fracture permeability and amplifying the nonlinear gas flow behavior. This study introduces a permeability-strain recovery zone and a novel sensitivity parameter <em>m</em>, delineating stress sensitivity boundaries for permeability and normal strain, with <em>m</em>-value increasing with stress, revealing four characteristic regions. These findings offer theoretical support for optimizing fracturing techniques to enhance resource extraction efficiency.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 345-362"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applicability of existing criteria of rockburst tendency of sandstone in coal mines","authors":"Tianqi Nan ,&nbsp;Linming Dou ,&nbsp;Piotr Małkowski ,&nbsp;Wu Cai ,&nbsp;Haobing Li ,&nbsp;Shun Liu","doi":"10.1016/j.ijmst.2025.01.008","DOIUrl":"10.1016/j.ijmst.2025.01.008","url":null,"abstract":"<div><div>To evaluate the accuracy of rockburst tendency classification in coal-bearing sandstone strata, this study conducted uniaxial compression loading and unloading tests on sandstone samples with four distinct grain sizes. The tests involved loading the samples to 60%, 70%, and 80% of their uniaxial compressive strength, followed by unloading and reloading until failure. Key parameters such as the elastic energy index and linear elasticity criteria were derived from these tests. Additionally, rock fragments were collected to calculate their initial ejection kinetic energy, serving as a measure of rockburst tendency. The classification of rockburst tendency was conducted using grading methods based on burst energy index (<em>W</em>_ET), pre-peak stored elastic energy (PES) and experimental observations. Multi-class classification and regression analyses were applied to machine learning models using experimental data to predict rockburst tendency levels. A comparative analysis of models from two libraries revealed that the Random Forest model achieved the highest accuracy in classification, while the AdaBoost Regressor model excelled in regression predictions. This study highlights that on a laboratory scale, integrating ejection kinetic energy with the unloading ratio, failure load, <em>W</em>_ET and PES through machine learning offers a highly accurate and reliable approach for determining rockburst tendency levels.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 417-431"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and application of rock rheological constitutive model considering dynamic stress field and seepage field","authors":"Yian Chen ,&nbsp;Guangming Zhao ,&nbsp;Wensong Xu ,&nbsp;Shoujian Peng ,&nbsp;Jiang Xu","doi":"10.1016/j.ijmst.2025.02.002","DOIUrl":"10.1016/j.ijmst.2025.02.002","url":null,"abstract":"<div><div>The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields. The results demonstrate that the rheological strain of the specimen under increased stress conditions is greater than that under creep conditions, indicating that the dynamic stress field significantly influences the rheological behaviours of sandstone. Following the rheological tests, the number of small pores in the sandstone decreased, while the number of medium-sized pores increased, forming new seepage channels. The high initial rheological stress accelerated fracture compression and the closure of seepage channels, resulting in reduction in the permeability of sandstone. Based on the principles of generalized rheology and the experimental findings, a novel rock rheological constitutive model incorporating both the dynamic stress field and seepage properties has been developed. Numerical simulations of surrounding rock deformation in geotechnical engineering were carried out using a secondary development version of this model, which confirmed the applicability of the generalized rheological numerical simulation method. These results provide theoretical support for the long-term stability evaluation of engineering rock masses and for predicting the deformation of surrounding rock.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 3","pages":"Pages 467-482"},"PeriodicalIF":11.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}