International Journal of Rock Mechanics and Mining Sciences最新文献

{"title":"Deep learning-based adaptive denoising method for prediction of crack opening displacement of rock from noisy strain data","authors":"Shuai Zhao ,&nbsp;Dao-Yuan Tan ,&nbsp;Jun Wang ,&nbsp;Jian-Hua Yin","doi":"10.1016/j.ijrmms.2025.106112","DOIUrl":"10.1016/j.ijrmms.2025.106112","url":null,"abstract":"<div><div>Precise prediction of crack opening displacement (COD) is necessary to control it within a certain threshold to ensure safety of critical buried rock structures (e.g. geological disposal facilities), and rock COD nowadays tends to be estimated using distributed fiber optic sensing (DFOS) data. The frequently used methods for computing COD of engineering structures from DFOS data are based on analytical models derived from strain transferring. However, these analytical models face significant challenges in computing COD when DFOS data exhibits high levels of noise. To address this limitation, this research aims to develop a deep attention threshold processing network (DATPN) to improve feature extraction ability from highly noisy DFOS data and accurately predict the COD of rock. A channel attention module is firstly designed and used as the main module by the DATPN to automatically learn thresholds adapting to different noises, so that the professional expertise is not required when determining noise thresholds. The learned noise thresholds are then provided to a built-in improved thresholding functions of the DATPN to eliminate data noise. Therefore, the DATPN can easily learn more useful target features to accurately predict the COD of rock owing to the elimination of data noise. The results indicate that the proposed DATPN achieves a maximal goodness of fit (<em>R</em>²) of 0.9924, a minimal mean squared error of 5.22, and a percent error for COD prediction ranging within ±10 % when evaluated using the original measured dataset. The <em>R</em>², correlation coefficient, root-mean-square error, and standard deviation for the DATPN (0.8407, 0.9193, 10.31, and 24.37) are superior to the other four machine learning models on the dataset with a signal-to-noise ratio of 0. This demonstrates that the DATPN is satisfactory in predicting the COD of rock from highly noisy DFOS data.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"190 ","pages":"Article 106112"},"PeriodicalIF":7.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815990","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":"Mechanical and degradation properties of rock under triaxial loading-unloading stresses: Comparative insights into coal and sandstone","authors":"You Lv ,&nbsp;Ru Zhang ,&nbsp;Anlin Zhang ,&nbsp;Zetian Zhang ,&nbsp;Li Ren ,&nbsp;Jing Xie ,&nbsp;Ersheng Zha","doi":"10.1016/j.ijrmms.2025.106102","DOIUrl":"10.1016/j.ijrmms.2025.106102","url":null,"abstract":"<div><div>Underground mining catastrophes mainly stem from the gradual weakening of coal and its adjacent rock formations, induced by complex stress variations occurring during loading and unloading processes. Although several cyclic loading and unloading tests have been conducted on rocks to evaluate this concern, there is a dearth of understanding of the distinct damage mechanisms that occur in coal and rocks under complicated triaxial cyclic loading-unloading (TCLU) stresses. Hence, a series of TCLU experiments considering variations in the upper stress limit and cycle numbers are conducted on coal and sandstone in this paper. Synchronised ultrasonic velocity measurements are performed, and the energy dissipation and wave velocity evolution methods are combined to characterise the rock damage process. The findings indicate that the dissipation energy–inducing damage increases with the upper stress limit in the single cycle. Compared to coal, sandstone shows a higher ability to store elastic energy. The rate and magnitude of energy release responsible for the structural deterioration in the sandstone appear notably larger than that in coal. Moreover, the differentiation of the sensitivity of acoustic waves to stress variations under TCLU is examined for coal and sandstone. Meanwhile, upon reaching peak stress, the deterioration index of coal increases slowly, whereas that of sandstone shows a rapid increase. A quantitative relationship established among ultrasonic wave velocity, stress and energy using polynomials provides the possibility of on-site stability analysis using ultrasonic measuring techniques.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"190 ","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143799327","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":"Isomerism of using the classic discretization algorithm Z2 for characterizing joint profile morphology roughness and its improvement","authors":"Binqiang Fan ,&nbsp;Changshuo Wang ,&nbsp;Liangqing Wang ,&nbsp;Linfeng Zhu ,&nbsp;Zihao Sun","doi":"10.1016/j.ijrmms.2025.106111","DOIUrl":"10.1016/j.ijrmms.2025.106111","url":null,"abstract":"<div><div>The discretization algorithm for the root mean square of the first derivative (RMSFD) significantly affects the effective characterization of rock joint profile roughness and the accurate evaluation of the joint roughness coefficient (JRC). The classic discretization algorithm <em>Z</em>₂ fails to distinguish morphology roughness differences in isomeric profiles, limiting its characterization capability. To address this, we revisit the original definition of RMSFD and propose an improved algorithm. The discretization scheme for curve profiles in the algorithm is modified. By fully considering the spatial configuration and mutual relationship of the position between adjacent-point microsegments, the forward difference form in <em>Z</em>₂ is changed to a central difference form, and another RMSFD discretization algorithm, <em>Z</em>_<em>n</em>, is developed. Comparative analysis of RMSFDs for reconstructed profiles using <em>Z</em>_<em>n</em> and <em>Z</em>₂ demonstrates that the proposed algorithm avoids isomerism and exhibits superior ability in characterizing profile morphology roughness. Furthermore, we establish a functional relationship between <em>Z</em>_<em>n</em> and JRC based on retrieved data and validate the superiority of the improved algorithm in characterizing profile morphology roughness. In addition, the capability of <em>Z</em>_<em>n</em> on the distinguishing differences of profiles is further confirmed, and the isomerism induced by other indicators is also examined. An anisotropic algorithm and three-dimensional (3D) improved discretization algorithms for the RMSFD are derived. The proposed algorithm <em>Z</em>_<em>n</em> is expected to enhance the understanding of morphology characteristics and improve the modeling of roughness for rock joints.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"190 ","pages":"Article 106111"},"PeriodicalIF":7.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792195","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":"Analysis of grout radial propagation in water-saturated rough-walled rock fractures","authors":"Hongyu Duan ,&nbsp;Yushi Xie ,&nbsp;Liangchao Zou ,&nbsp;Bo Li ,&nbsp;Ulf Håkansson ,&nbsp;Vladimir Cvetkovic","doi":"10.1016/j.ijrmms.2025.106101","DOIUrl":"10.1016/j.ijrmms.2025.106101","url":null,"abstract":"<div><div>Understanding the propagation behavior of cement grout in rough-walled fractures is crucial for predicting its effectiveness and design of optimal grouting schemes. To investigate radial propagation of cement grout in saturated rough-walled fractures, a water-cement grout two-phase flow model in rough-walled rock fractures is developed using the phase field method, Herschel-Bulkley model, and mass and momentum conservation equations. Then, the established model is validated against analytical solutions and rough fracture grouting tests. Subsequently, the sensitivity of grout propagation versus grout rheological properties, injection pressure and fracture geometry is analyzed. Simulation results reveal that the increase in water-to-cement ratio (W/C) and injection pressure can enhance the filling rate and flow rate of cement grout in rough-walled fractures. Nevertheless, regardless of adjusting W/C and injection pressure, there is a maximum filling rate for a certain fracture that cannot be exceeded. An increase in the relative standard deviation (RSD) of fracture aperture may promote preferential paths' formation to facilitate better penetration by the grout; although, excessive RSD may enlarge areas where it is difficult for grout to penetrate effectively. Additionally, the fracture shear direction significantly affects the propagation direction of cement grout, with preferential propagation occurring perpendicular to the fracture shear direction. Finally, the comparison between the rough-walled fracture model and smooth parallel-plate fracture models from previous research indicates that the smooth parallel-plate models might overestimate the grout filling rate by about 30 %, while significantly underestimating the grout flow. These results provide valuable insights for more accurate predictions of grouted penetration ranges and for optimizing rock grouting methods such as real-time grout control (RTGC).</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"190 ","pages":"Article 106101"},"PeriodicalIF":7.0,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777332","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":"An extended bond-based peridynamic model with bond transverse deformation effects for quasi-brittle rocks","authors":"Wei-Jian Li ,&nbsp;Qi-Zhi Zhu ,&nbsp;Yan-Liang Du ,&nbsp;Jian-Fu Shao","doi":"10.1016/j.ijrmms.2025.106099","DOIUrl":"10.1016/j.ijrmms.2025.106099","url":null,"abstract":"<div><div>The bond-based peridynamics shows significant potential in describing and simulating the continuous-discontinuous problems like rock mass. However, the theory developed so far with account of the bond stretch and shear mechanisms exhibits unreasonable prediction of bond force and the appearance of negative shear stiffness when Poisson’s ratio exceeds a critical value. In this work, the root cause behind the negative shear stiffness problems is identified and solved by originally incorporating the effect of transverse deformation in addition to the bond stretch and rotation. In this way, the elastic response of peridynamic bond is completed and becomes multi-dimensional. Also, the bond-scale formulations can be regarded as a nonlocal version of the generalized Hooke’s Law. A novel multi-dimensional bond-based peridynamic model is developed, which is capable of describing rock deformation and mixed-mode fracture process. Several benchmark tests are performed to assess the effectiveness and robustness of the method. The proposed model not only overcomes the theoretical deficiency of traditional ones but also allows more suitable description and simulation of rock behavior on different scales.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"190 ","pages":"Article 106099"},"PeriodicalIF":7.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768226","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":"Influence of lithological contrast on elastic anisotropy of shales under true-triaxial stress and thermal conditions","authors":"Chinmay Sethi ,&nbsp;Hem Bahadur Motra ,&nbsp;Bodhisatwa Hazra ,&nbsp;Mehdi Ostadhassan","doi":"10.1016/j.ijrmms.2025.106100","DOIUrl":"10.1016/j.ijrmms.2025.106100","url":null,"abstract":"<div><div>The intrinsic anisotropy of shales, arising from their complex microstructure, including mineral alignment and bedding orientation, significantly influences seismic wave propagation, impacting subsurface imaging and reservoir characterization. Despite extensive research on shale anisotropy, studies employing cubic specimens under true-triaxial conditions, which provide a more realistic simulation of subsurface stress states, remain limited. This study investigates the elastic anisotropic behaviour of two distinct shale lithotypes: grey shale (GSH) and silty shale (SSH) from the Permian Barakar Formation of Lower Gondwana in the Jharia Basin, India, under varying isostatic pressures (8 MPa, 12 MPa, 25 MPa, 35 MPa, and 51 MPa) and temperatures (20 °C, 50 °C, 100 °C, 150 °C, and 200 °C) using a polyaxial loading apparatus. Compressional (Vp) and shear wave (Vs) velocities were measured in multiple orientations—parallel, perpendicular, and at 45° to the bedding plane—allowing for a comprehensive evaluation of elastic properties. The results reveal that both Vp and Vs exhibit a noticeable increase with rising isostatic pressure, indicating enhanced stiffness due to the closure of microcracks and pores. Moreover, GSH consistently demonstrated higher wave velocities compared to SSH, attributed to its higher quartz content and mineral alignment, which contributed to reduced shear wave splitting. The analysis of dynamic bulk modulus (K) indicated a consistent increase with pressure for both shale types, with GSH exhibiting a more linear response compared to the non-linear behaviour observed in SSH, influenced by its clay-rich composition. Temperature-induced changes in elastic properties were minimal, with only slight decrease in wave velocities observed at higher temperatures under constant pressure, inferring to the stability of the shale structure. This stability suggests that thermal expansion and mineralogical transformations do not significantly impact the elastic behaviour of these shales within the temperature range of the test. Furthermore, Thomsen anisotropy parameters (ε and γ) exhibited distinct trends under varying pressure and temperature conditions where overall a reduction in anisotropy was observed with increased pressure, reflecting a transition to more isotropic behaviour as pre-existing microcracks closed. The study provides a baseline understanding of variations in elastic properties of two different shale lithotypes to support subsurface resource exploitation strategies, underscoring the significance of employing cubic specimens under true-triaxial conditions to accurately simulate subsurface stress states.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"190 ","pages":"Article 106100"},"PeriodicalIF":7.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760428","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":"Multitask intelligent early warning of rockbursts based on classification-regression cascaded network model","authors":"Jiaming Li ,&nbsp;Shibin Tang ,&nbsp;Jinglan Zhang ,&nbsp;Beichang Tang ,&nbsp;Shuguang Zhang","doi":"10.1016/j.ijrmms.2025.106103","DOIUrl":"10.1016/j.ijrmms.2025.106103","url":null,"abstract":"<div><div>With the expansion of underground engineering into deeper levels, the frequency of rockburst disasters has gradually increased, posing serious threats to the safety of construction personnel and equipment. The occurrence of rockbursts typically involves information about time, location, and intensity, which makes it challenging for traditional single‒intelligence prediction methods to capture the multiple characteristics of rockbursts simultaneously and comprehensively. In this study, we established a rockburst prediction dataset that includes temporal information, locational information, construction factors, and microseismic source parameters. The correlation between each parameter was analysed, and the classification‒regression cascaded network model was constructed to provide a multitask early warning method for rockbursts. The method addressed the problem of imbalanced samples with different rockburst intensity grades and achieved multitask early warning for rockburst intensity grade classification, occurrence time, and location. Through comprehensive evaluation, the convolutional neural network - gated recurrent unit (CNN–GRU) and convolutional neural network ‒ feedforward neural network (CNN‒FNN) models outperform the ResNet18–GRU and UNet–GRU models in terms of the prediction of the rockburst intensity grade, occurrence time, and location. Concurrently, a dynamic prevention and control strategy for rockbursts, which involves ‘short‒term prediction to ensure personnel safety and long‒term prediction to adjust support and prevention and control’, was proposed. Finally, the weighting of the influence of each input parameter on the prediction of the rockburst intensity grade, occurrence time, and location was discussed. The findings indicate a high weighting of the combined effect of energy, static stress drop, and <em>E</em>_S/<em>E</em>_P on rockbursts. This study proposes an innovative and practical method for rockburst prediction, providing theoretical and technical support for early warning and control of rockburst in underground engineering.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"189 ","pages":"Article 106103"},"PeriodicalIF":7.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738075","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":"What if chalk becomes mechanically weaker during supercritical CO2 injection in a depleted gas reservoir?","authors":"Amour F.,&nbsp;Hosseinzadeh B.,&nbsp;Hajiabadi M.R.,&nbsp;Nick H.M.","doi":"10.1016/j.ijrmms.2025.106093","DOIUrl":"10.1016/j.ijrmms.2025.106093","url":null,"abstract":"<div><div>Even though most past endeavors concluded no significant mechanical weakening of chalk flooded by supercritical CO₂, here, we comprehensively assess the mechanical response of a depleted chalk reservoir by considering the most pessimistic experimental results reported in literature in terms of mechanical alteration of chalk by supercritical CO₂. The primary aim stems from the lack of simulation studies documenting the deformation behaviour of CO₂ storage site in chalk. We perform a series of hydro-mechanical simulations on the Harald East gas field, the first candidate worldwide to store CO₂ in chalk formations located in the Danish North Sea. Different scenarios are considered by modifying the injection schemes (intermittent <em>vs</em>. continuous, low <em>vs.</em> high injection rate) and assumptions regarding the CO₂-induced alteration of the rock's properties. The subsidence trends of the reservoir top and the distribution of stress and elasto-visco-plastic strain across the reservoir, underburden, and along the wells are compared between scenarios. Besides, the mechanical responses of subsurface chalk upon pressure depletion during gas production and repressurisation by CO₂ injection are reviewed. The results highlight the effects of stress arching occurring during production as well as the injection rate, distance of porous chalk from injectors, timing between repressurisation and CO₂ propagation, and elastic strain rebound on the deformation response of the storage site. The present study also indicates that the field exhibits an overall negligible to minor deformation during the injection phase compared to the production phase, thereby providing encouraging results on the feasibility of re-purposing depleted chalk reservoirs as storage sites.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"189 ","pages":"Article 106093"},"PeriodicalIF":7.0,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724883","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":"Physical modeling experiment of a novel concrete lining for high-pressure tunnels","authors":"Qiang Zhang ,&nbsp;Chaojun Jia ,&nbsp;Zhengyun Qin ,&nbsp;Lipeng Liu ,&nbsp;Liang Wang ,&nbsp;Yujie Wang","doi":"10.1016/j.ijrmms.2025.106094","DOIUrl":"10.1016/j.ijrmms.2025.106094","url":null,"abstract":"<div><div>The unpredictable development of random cracks in reinforced concrete linings under high internal water pressures poses significant challenges for the operational safety and management of hydraulic tunnels, particularly in water-permeable linings used in pumped storage power stations. To address this issue, this study introduces an innovative structural design: a reinforced concrete water-permeable lining with a prefabricated crack (also referred to as a contraction joint). This design enhances the measurability, controllability, and prevention of crack propagation in high-pressure tunnels, offering a groundbreaking solution to mitigate uncertainty in lining behavior. A custom physical model testing system was developed to simulate the filling and draining processes of high-pressure tunnels, enabling precise measurement of critical parameters such as internal and external water pressures, reinforcement stresses, concrete strains, and crack widths. Physical model tests on linings with prefabricated cracks revealed their operational mechanisms, demonstrating that cracks initiate at predetermined locations during the initial water-filling phase. Subsequently, the lining and reinforcements transition from a tensile to a compressive stress state, effectively preventing the formation of additional random cracks. Throughout operational cycles, the lining remains in compression, with no new crack development. The detailed elucidation of the stress evolution and cracking mechanisms in water-permeable linings, while its engineering significance is underscored by the development of a practical, replicable design and testing methodology. These advancements provide a robust framework for improving the design and management of high-pressure tunnel linings, with broad applicability to pumped storage power stations and similar infrastructure.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"189 ","pages":"Article 106094"},"PeriodicalIF":7.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706353","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":"Novel insights into grain size effect of stressed crystalline rock using weakened grain boundary model","authors":"Zheng Yang ,&nbsp;Ming Tao ,&nbsp;P.G. Ranjith","doi":"10.1016/j.ijrmms.2025.106098","DOIUrl":"10.1016/j.ijrmms.2025.106098","url":null,"abstract":"<div><div>The grain size effect of rocks is crucial for engineering applications, including mining, tunneling, and oil extraction. Previous studies on the effect of grain size revealed discrepancies between experimental results and numerical simulations, hindering accurate predictions of rock strength and deformation. Initially, a parallel bond model was applied to describe the grain boundary contacts and investigate the effect of the grain size under initial stress conditions. The results of this model indicated that the uniaxial compressive strength (UCS) and Young's modulus increased with an increasing grain size, thus contradicting the experimental findings. Under the initial stress, the sample strength exhibited an irregular variation with grain size in this model. By analyzing the differences between the experimental and numerical results, a novel weakening grain boundary model (WGBM) that considers the strength and Young's modulus is proposed. The introduction of a grain boundary degradation factor provides a practical method by which to simulate the reductions in the strength and Young's modulus at grain boundaries as the grain size increases, which thereby enables a more realistic representation of the rock grain boundary behavior. The WGBM captured the experimental trends more accurately, and the UCS and Young's modulus decreased with an increasing grain size. Without the initial stress, the ratio of intergranular to intragranular cracks exceeded 2.5. The initial stress suppressed the propagation of intergranular cracks, and the intergranular and intragranular cracks were concentrated in one or more shear bands. Under initial stress conditions, the strength fluctuated slightly with an increasing grain size but showed an overall decreasing trend. The results and methods provide new insights into rock mechanics and related applications.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"189 ","pages":"Article 106098"},"PeriodicalIF":7.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714685","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}