International Journal of Rock Mechanics and Mining Sciences最新文献

{"title":"Tensile fracture characteristics and directional fracturing mechanism of 2D blasting: Experimental investigation and theoretical modelling","authors":"Shan Guo ,&nbsp;Manchao He ,&nbsp;Quan Zhang ,&nbsp;Yulong Shao ,&nbsp;Chao Wang ,&nbsp;Jianning Liu","doi":"10.1016/j.ijrmms.2025.106059","DOIUrl":"10.1016/j.ijrmms.2025.106059","url":null,"abstract":"<div><div>Blasting is a crucial technique for rock breaking in geotechnical engineering, with directional fracture-controlled blasting being one of its most important applications. To advance this field, a novel non-explosive blasting method, termed two-dimensional blasting (2D blasting), has been developed. This innovative technique utilizes high-temperature, high-pressure gas generated by expansion agent to induce tensile stress along the splitting direction of the borehole wall, facilitating directional rock mass rupture. The research and theoretical modelling of the directional fracturing mechanism for 2D blasting are extremely challenging, but this is crucial for the field application and parameter design of 2D blasting technology. In this study, comparative experiments were conducted using concrete specimens subjected to both 2D and conventional blasting. Dynamic crack propagation behaviour was recorded with a high-speed camera, and tensile fracture characteristics were analysed using the Digital Image Correlation (DIC) method. The experimental results revealed that conventional blasting generates random, disordered radial cracks around the borehole, forming a three-dimensional (3D) fracture network. In contrast, 2D blasting employs an energy-gathering device to regulate stress distribution on the borehole wall, transforming the 3D fracture network into a two-dimensional (2D) fracture plane in the preset direction. Building on these experimental findings, mechanical models for both conventional and 2D blasting were established. The stress concentration effects around the borehole wall under 2D blasting were analysed, and criteria for crack initiation and propagation in 2D blasting were proposed. The results confirmed the directional fracturing efficacy of 2D blasting, characterized its tensile fracture behaviour, and provided valuable insights into its underlying mechanisms, offering a reference for further advancements in directional fracture-controlled blasting technologies.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"187 ","pages":"Article 106059"},"PeriodicalIF":7.0,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting three-dimensional roughness of rock discontinuity based on limited outcrop information during tunnel construction","authors":"Qi Zhang ,&nbsp;Yuechao Pei ,&nbsp;Hehua Zhu ,&nbsp;Xiaojun Li ,&nbsp;Fenghe Guo ,&nbsp;Yixin Shen","doi":"10.1016/j.ijrmms.2025.106040","DOIUrl":"10.1016/j.ijrmms.2025.106040","url":null,"abstract":"<div><div>Three-dimensional (3D) roughness of the rock discontinuity plays a controlling function on the rock mass stability of excavation face during deep buried tunnel construction, which can be predicted based on the discontinuity outcrop from excavation face. However, there exist some disturbing factors such as dust and debris which affect the non-contact measurement accuracy on the outcrop information under construction environment. In this study, a new method to predict three-dimensional roughness of rock discontinuity (JRC_3d) based on the limited outcrop and drilling test information from the rock mass of excavation face is proposed. Two-dimensional roughness of rock discontinuity (JRC_2d) is derived based on different asperity orders firstly. The first-order profile roughness is calculated by combining drilling test result, and the second-order profile roughness is predicted on establishing the statistical relationship between the geometrical parameter of the outcrop and the entire profile. Based on the prediction of JRC_2d, JRC_3d is characterized probabilistically with the improved Bayesian theory where the bootstrap method is used to deal with the difficulty of obtaining <em>μ</em> and <em>σ</em> of the prior distribution because the sample size is limited. A rock tunnel engineering in southwest China is taken as the engineering application, and the relative errors of the predicting JRC_3d are lower than 11 %. Finally, the effect of outcrop width on the predicting JRC_3d results is investigated. For Barton standard profiles, the statistical parameters of the first <em>k</em> climbing angles of the second-order roughness profiles are calculated to estimate the appropriate outcrop width as 16 mm. A rock discontinuity is generated to study the effect of discontinuity size on the predicting JRC_3d, and the relative error of the predicting JRC_3d is lower than 12 %, thereby validating the method applicability across a broad spectrum of discontinuity sizes, ranging from small to large.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"187 ","pages":"Article 106040"},"PeriodicalIF":7.0,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New insights into the continuous-discontinuous failure characteristics of granite under Brazilian splitting test conditions using acousto-optic-mechanical (AOM) method","authors":"Zhen Heng ,&nbsp;Tao Xu ,&nbsp;Heinz Konietzky ,&nbsp;Wancheng Zhu ,&nbsp;P.G. Ranjith","doi":"10.1016/j.ijrmms.2025.106041","DOIUrl":"10.1016/j.ijrmms.2025.106041","url":null,"abstract":"<div><div>Tensile failure in brittle rocks is crucial for the stability of rock engineering applications. However, a comprehensive quantitative evaluation of continuous-discontinuous tensile failure characteristics and the effect of loading platen shape on the microcracking behavior induced by tensile stress in granite, as well as the corresponding variations in the evolution of Fracture Process Zone (FPZ) at the microscale, remain unclear. This study describes an effective acousto-optic-mechanical multi-physical field observation system to capture the real-time acoustic, optical and mechanical response of a coarse-grained granite during Brazilian splitting tests applying various loading platen shapes. An improved 3D acoustic emission (AE) location algorithm is introduced and validated to interpret the spatio-temporal evolution of crack source mechanisms. Three stages of microcracking, namely quiet stage (QS), stable stage (SS), and outburst stage (OS) are identified based on the AE characteristics. We found that a distinction between different loading conditions is easier to detect at relatively low loading rates. Digital Image Correlation (DIC) results show that the loading platen shape affects the initial position of the tensile stress-induced crack initiation and the corresponding deformation. High-Speed Photography (HSP) images captures the evolution of FPZ and visible crack opening behavior. Both, indirect tensile strength and splitting elastic modulus are found to be sensitive to loading rates, with varying degrees of sensitivity under different loading conditions. The fractal dimension results closely correlate with the monitored COD outcomes, highlighting a smaller Joint Roughness Coefficient (<em>JRC)</em> value on the failure surface under arc platen loading conditions compared with flat platen loading conditions. The evolution of <em>b</em>-values reveals the transition from microcracking to macrocracking, which is consistent with the stress and FPZ evolution. The influence of loading platen shape on indirect tensile strength and failure characteristics of granite is theoretically validated. Finally, correlations among the AOM characteristics under different loading conditions and their practical implications are investigated.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"187 ","pages":"Article 106041"},"PeriodicalIF":7.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic extraction and quantitative analysis of characteristics from complex fractures on rock surfaces via deep learning","authors":"Mingze Li ,&nbsp;Ming Chen ,&nbsp;Wenbo Lu ,&nbsp;Peng Yan ,&nbsp;Zhanzhi Tan","doi":"10.1016/j.ijrmms.2025.106038","DOIUrl":"10.1016/j.ijrmms.2025.106038","url":null,"abstract":"<div><div>The detection and evaluation of rock mass joints and fractures are essential in assessing the stability of engineering rock masses and mitigating geological hazards. To address the challenge of intelligent extraction and quantification of fractures, a deep learning-based complex rock fracture segmentation network, termed CRFSegNet, has been developed and combined with multiple feature computation methods. Ablation experiments and multi-model comparisons are conducted on a self-constructed dataset comprising fractures induced by natural processes and blasting. CRFSegNet performs competitively in terms of visualization and evaluation metrics in comparative experiments, with an average intersection-over-union of 83.90 %. The network effectively captures the intricate characteristics of fractures, demonstrating the approach's robustness and competitiveness. Fracture characteristics, such as length-dip, surface fracture rate, and fractal dimension, are obtained based on the segmentation results and the proposed characteristic calculation method. By analyzing the feature acquisition of four images, it is found that the results based on CRFSegNet are basically consistent with the actual situation, which shows that the proposed method is an effective approach for intelligent recognition and feature acquisition.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"187 ","pages":"Article 106038"},"PeriodicalIF":7.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143322236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Roof stability for rock cavities and tunnels: Revisiting limit state plastic analysis","authors":"Dowon Park","doi":"10.1016/j.ijrmms.2024.106008","DOIUrl":"10.1016/j.ijrmms.2024.106008","url":null,"abstract":"<div><div>Previous observations of the roof stability analyses for deep-depth tunnels in continuum rock mass suggest that the critical roof failure mechanism involves a <em>π</em>/2-rotation of the failure envelope utilized in the analysis. In this study, the results obtained from the kinematic approach of the limit analysis and limit equilibrium method demonstrated that the failure profile of a roof collapse in a physical space is equivalent to the rotated and scaled shear strength envelope in the stress plane. An analytical technique employing parametric expressions is presented to account directly and accurately for the generalized Hoek–Brown criterion without requiring knowledge of its closed-form shear strength envelope or replacing it with approximated functions. The solutions obtained from the two independent methods, that is, the pure and lesser forms of the upper-bound approach, were identical owing to the rigid-block translational mechanism. In addition, several interesting aspects of the mechanics of incipient roof collapse are investigated by inspecting the stress state and failure mechanism in compliance with static force equilibrium and kinematic compatibility. The proposed method overcomes the limitations of conventional studies conducted in this category.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106008"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142974942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A high-fidelity digital rock representation based on digital grinding combined with deep learning for four-dimensional lattice spring model","authors":"Gao-Feng Zhao,&nbsp;Yu-Hang Wu,&nbsp;Xin-Dong Wei","doi":"10.1016/j.ijrmms.2024.106004","DOIUrl":"10.1016/j.ijrmms.2024.106004","url":null,"abstract":"<div><div>This paper introduces a method for constructing high-fidelity digital rock using digital grinding and deep learning, specifically for the Four-Dimensional Lattice Spring Model (4D-LSM). Initially, rock sequence images are captured with a self-designed digital grinding equipment. Bicubic interpolation is then applied to fill missing pixels, ensuring uniform resolution. The images are subsequently deblurred using DeblurGAN, a deep learning network trained with existing high-definition images. This process results in high-fidelity 3D true-color digital rock geometry reconstruction. An Artificial Neural Network (ANN) identifies mineral components, which are then mapped into the 4D-LSM to create the high-fidelity 3D true-color Grain-Based Model (GBM). The mechanical behavior of the GBM is analyzed using the 4D-LSM, incorporating strength reduction factors which can be easily calibrated through a modified Newton algorithm. Results demonstrate that the high-fidelity 3D true-color GBM accurately replicates the mechanical behavior and failure processes of granite, offering improved consistency with experimental data compared to homogeneous models.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106004"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermally induced fracture modeling during a long-term water injection","authors":"Yuhao Liu ,&nbsp;Keita Yoshioka ,&nbsp;Tao You ,&nbsp;Hanzhang Li ,&nbsp;Fengshou Zhang","doi":"10.1016/j.ijrmms.2024.106022","DOIUrl":"10.1016/j.ijrmms.2024.106022","url":null,"abstract":"<div><div>Significant volumes of water are injected into the subsurface for purposes such as maintaining reservoir pressure, enhancing production efficiency, or water disposal. In these operations, injection pressures are typically kept low to prevent the formation from fracturing. However, fractures may still be induced even at low injection pressures if the injected water cools the formation, causing thermal contraction. In this study, we numerically investigate thermally induced fractures during water injection using a variational thermo-hydro-mechanical phase-field model. Our simulation results show that cold water injection can nucleate multiple thermal fractures nearly orthogonal to a stimulated fracture, even if the injection pressure is below the fracturing pressure. Further simulation scenarios reveal that thermal fracture propagation is more likely with larger temperature differences, smaller in-situ stress anisotropy, and lower formation permeability. This study highlights the significant impact of thermal effects on fracture initiation and propagation, suggesting the need for careful consideration when regulating or managing fracture initiation during water injection.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106022"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling microwave fracturing of rocks: A continuum-discontinuum numerical approach","authors":"Yinjiang Nie,&nbsp;Yanlong Zheng,&nbsp;Jianchun Li","doi":"10.1016/j.ijrmms.2024.105975","DOIUrl":"10.1016/j.ijrmms.2024.105975","url":null,"abstract":"<div><div>Existing numerical models cannot well reproduce the fracturing process and reveal the underlying mechanisms of rocks under microwave irradiation. In this work, the electromagnetic-thermal-mechanical multiphysics is decoupled into microwave-induced heating (continuum-based) and thermally-driven fracturing (discontinuum-based), with temperature serving as the key interlink. The rigid-body spring-subset network (RBSSN) model is proposed to calculate the progressive fracturing of rocks under open-ended microwave irradiation, where the individual contacts between adjacent tetrahedral blocks are disassembled into three hypothetical spring-subsets. To depict failure characteristics of large-scale rocks under microwave irradiation, a variable-sized block model is developed by densifying the rigid-blocks near the irradiation. This electromagnetic-thermal-mechanical decoupling framework effectively captures the microwave fracturing process, revealing that microwave irradiation induces tensile-dominant progressive failure and regionalized deterioration (localized damage and macroscopic radial fissure). The fracturing rate of rocks is time-dependent, progressing through silent, violent and slowdown periods of rupturing with extended exposure time. The reason why high-power microwave is more effective in promoting visible fractures under the identical input energy is analyzed by combining the thermal deformation theory and RBSSN simulation. It is found that, power levels should be kept within reasonable scopes to maximize fracturing effects as excessive power densities lead to initiation of numerous microcracks around the high temperature zone and susceptibility to spalling.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 105975"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visualization of the dynamic propagation of two simultaneously-stimulated hydraulic fractures: Competition and interaction","authors":"Luchao Wang ,&nbsp;Kang Duan ,&nbsp;Qiangyong Zhang ,&nbsp;Xiufeng Zhang ,&nbsp;Chuancheng Liu ,&nbsp;Di Wang","doi":"10.1016/j.ijrmms.2025.106036","DOIUrl":"10.1016/j.ijrmms.2025.106036","url":null,"abstract":"<div><div>Deepening the understanding of the dynamic propagation and interaction of multiple hydraulic fractures is the key to the optimization of hydraulic fracturing design. By conducting two-hole hydraulic fracturing experiments on transparent polymethyl methacrylate (PMMA) samples, we visualize the dynamic propagation of fractures stimulated from two holes in three dimensions with the aid of high-speed cameras and image reconstruction methods. The characteristics of hydraulic fracture growth were discussed in conjunction with extended finite element method (XFEM) simulation and theoretical analysis. The competition between the boundary stress and the internal stress from the holes controls the growth mode of the fractures. The reduction of boundary stress difference intensifies the stress concentration between holes, resulting in the transformation of planar fractures formed from a single hole into spiral fractures connecting two holes. The propagation of double-hole spiral fractures can be divided into hole connection, deflection and rapid propagation stages. The fractures first connect the two holes dominated by the stress concentration, and then reoriente to the σ_H direction under the control of the boundary stress. The propagation of single-hole planar fractures can be divided into upward propagation, bilateral synchronization and downward propagation stages. The fracture propagating in the σ_H direction first appears on the single-hole side under the control of boundary stresses, and then deflects towards the adjacent hole influenced by the attraction stresses from adjacent holes. The propagation of two-hole hydraulic fractures has obvious sequence, and the stress repulsion of the primary fracture makes the secondary fracture propagate in opposite direction.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106036"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A nonlinear inversion method for predicting the in-situ stress field in deep coal seam based on improved long short-term memory neural network","authors":"Jiaxing Zhou ,&nbsp;Bisheng Wu ,&nbsp;Yuanxun Nie ,&nbsp;Haitao Zhang","doi":"10.1016/j.ijrmms.2024.106020","DOIUrl":"10.1016/j.ijrmms.2024.106020","url":null,"abstract":"<div><div>Existence of discontinuous geological structures, such as folds and fault, poses a great challenge in predicting the in-situ stress fields (ISSF). This paper proposes a discontinuous intelligent inversion method to predict the ISSFs in the deep coal seam area (DCSA) of the Shanghai Temple, which exhibits distinct discontinuous geological features. The proposed method consists of three key components. First, a discontinuous loading model was developed to address the problem of accuracy in the numerical simulation of discontinuous tectonic regions such as folds and faults. The simulation data generated is used as a sample dataset for the training of the inversion algorithm and their completeness is fully guaranteed. Second, the statistical distribution patterns of horizontal, maximum and minimum lateral pressure coefficients (LPCs) of the ISSF in the typical DCSAs of China is statistically calculated. By applying Gaussian- and Cauchy-type fuzzy membership functions, the degree of influence of faults and folds on the local ISSF is quantified and the geological structure influence model is constructed. The influence value enriches the input data dimension of the algorithm and lays a more detailed data foundation for the stress inversion. Third, the improved Long Short-Term Memory (LSTM) network algorithm was constructed by optimizing the network hierarchy and multi-parameter cyclic learning. An inversion analysis is carried out using the ISSF around the borehole as an example, and the relative error strictly controlled within 1 %. The improved LSTM algorithm achieves an accuracy of 88.58 % at each measurement point in the Shanghai Temple deep coal seam project, which is significantly higher than that of the back propagation neural network (BPNN). The discontinuous intelligent inversion method proposed in this study can provide an effective tool for predicting the ISSF in DCSA.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106020"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142974938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}