International Journal of Rock Mechanics and Mining Sciences最新文献

{"title":"Comprehensive in-situ stress estimation in a fractured geothermal reservoir in Pohang, South Korea using drilling data, hydraulic stimulations, and induced seismicity","authors":"Sehyeok Park ,&nbsp;Kwang-Il Kim ,&nbsp;Hwajung Yoo ,&nbsp;Juhyi Yim ,&nbsp;Ki-Bok Min","doi":"10.1016/j.ijrmms.2024.105978","DOIUrl":"10.1016/j.ijrmms.2024.105978","url":null,"abstract":"<div><div>A comprehensive in situ stress estimation is carried out in the fractured reservoir at the enhanced geothermal system development site in Pohang, South Korea. Various types of stress indicators were collected from the hydraulic stimulation data, drilling records, lost circulation records, well logs, seismic events, and the stress constraints from previously proposed stress models. The comprehensive comparison of the collected stress constraints was performed, and resulted in the possible stress magnitude range and corresponding limits on the range of possible friction coefficients. The resulting stress ratio is <em>S</em>_<em>V</em>: <em>S</em>_{<em>hmin</em>}: <em>S</em>_{<em>Hmax</em>} = 1 : 0.92–0.94 : 1.42–1.66 with the azimuth of <em>S</em>_{<em>Hmax</em>} in N101°E –N110°E range, based on the compilation of both direct and indirect stress information. The results also suggest a friction coefficient range of 0.35–0.38 that can best explain the involved stress constraints. The stress model suggested in this study can explain the characteristics of the M_w 5.5 Pohang earthquake in November 2017 in terms of reproducing the slip rake of mainshock and the slip tendency of the corresponding fault. Therefore, the result can be used for clarifying the causal mechanism of the Pohang earthquake, providing an insight for fault stability analysis or possible geo-energy application in the southeastern part of the Korean Peninsula. Comprehensive in-situ stress estimation method suggested in this study integrating extensive direct and indirect stress indicators can improve the credibility of the in-situ stress model at a fractured reservoir.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 105978"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142793448","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":"Experimental study of hydraulic fracture propagation in multi-hole synchronous fracturing in horizontal wells in sandstone","authors":"Yulong Jiang ,&nbsp;Weiguo Liang ,&nbsp;Haojie Lian ,&nbsp;Wei He","doi":"10.1016/j.ijrmms.2024.106013","DOIUrl":"10.1016/j.ijrmms.2024.106013","url":null,"abstract":"<div><div>Hydraulic fracture propagation in multi-hole synchronous fracturing plays a critical role in forming complex fracture networks in unconventional reservoirs. However, the propagation mechanism of multi-hole synchronous fracturing is still unclear, especially the effects of the fracturing borehole spacing and natural fracture. In this study, a series of experiments using a triaxial loading system were conducted to investigate the stress shadow effect in multi-hole hydraulic fractures propagation with different borehole spacings and the interaction between hydraulic fractures and natural fractures in specimens during hydraulic fracturing. The results indicated the following: 1) There is an obvious stress shadow effect in multiple fracture propagation, significantly influencing the fracture propagation path, direction and fracture initiation pressure. Hydraulic fracture propagation in multi-hole fracturing tests in specimens with different fracturing borehole spacings is significantly different, and increasing the fracturing borehole spacing can effectively change the fracture propagation path in the interior borehole and reduce the stress shadow effect. Compared to single cluster fracturing, hydraulic fractures in multi-hole fracturing show a single-wing form instead of double-wing propagation at the pre-existing artificial fractures, presenting asymmetrical and elliptical propagation of hydraulic fractures network. (2) The stress shadow effect effectively helps communicate adjacent fractures, resulting in a more complex fractures network. Under the stress conditions of 5/8/12 MPa and specimen size of 300 × 300 × 50 mm, when the fracturing hole spacing is small (less than 50 mm), hydraulic fractures perpendicular to the direction of the minimum horizontal principal stress generate from the external fracturing holes on both sides, and the hydraulic fractures parallel to the direction of the minimum horizontal principal stress generate from the middle fracturing hole. These hydraulic fractures propagate and interconnect, forming a complex fracture network. There is a critical spacing of 50 mm. (3) Under the influence of stress shadow, multiple fractures are more likely to penetrate artificial pre-existing fractures compared to hydraulic fractures in single fracturing hole, and can more effectively connect artificial pre-existing fractures, resulting in more complex fracture shapes.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106013"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901910","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 mathematical model for the shape prediction of bedded salt cavern used for energy storage","authors":"Tao He ,&nbsp;Tongtao Wang ,&nbsp;Chunhe Yang ,&nbsp;Youqiang Liao ,&nbsp;Dongzhou Xie ,&nbsp;Zhekang Ding ,&nbsp;J.J.K. Daemen","doi":"10.1016/j.ijrmms.2025.106029","DOIUrl":"10.1016/j.ijrmms.2025.106029","url":null,"abstract":"<div><div>The vertical layering and anisotropic characteristics of bedded rock salt are different from those of salt mounds, and the brine reinjection operation during the cavern creation process makes it difficult to predict the distribution of brine concentration in the cavern. The accumulation of slag in the complex cavern affects the brine flow characteristics and cavern volume, which makes the water-soluble cavern formation in bedded rock salt deviate from the expected design. In this paper, we propose the control scheme and required technology for cavern construction system in bedded rock salt, establish the prediction theory of brine cavern concentration and flow rate considering the cavern morphology and brine injection and drainage scheme, establish the prediction theory of dissolution morphology and insoluble matter morphology considering the difference of mineral components, and complete the coupled solution of the flow field, concentration field, morphology expansion, and insoluble matter morphology prediction, and give an example of software platform development with parameter input and graphic display function. A software platform development example with parameter input and graphic display functions is provided to facilitate engineers’ use. After the function test and the calculation of the cavern creation example, this paper can improve the stability of the control of cavern creation in bedded rock salt.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106029"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990425","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 data-driven method for the deformation analysis of layered rocks","authors":"Fanding Feng,&nbsp;Diansen Yang,&nbsp;Qinghui Jiang","doi":"10.1016/j.ijrmms.2025.106030","DOIUrl":"10.1016/j.ijrmms.2025.106030","url":null,"abstract":"<div><div>This paper proposes a data-driven method for the deformation analysis of layered rocks, which consists of generating a stress–strain database and using a data-driven computational solution. The method does not require defining the material's constitutive relationship to conduct analysis of layered rock deformation under loading of the same material. First, the data-driven identification (DDI) algorithm infers and builds a stress‒strain database of the material based on the strain field and loading force. Then, this database is used to calculate the response of the same material structure with arbitrary geometry and boundary conditions using data-driven computational mechanics (DDCM). The specific workflow of the method is demonstrated, and the computational accuracy and reliability are verified through an experimental application example. The method naturally combines the DDI algorithm and the DDCM solver, providing a new concept for analysing the deformation of layered rocks. Through this method, it is possible to conduct more accurate deformation analysis of layered rocks without defining their constitutive relationships. This has significant engineering application value in the design of excavations for layered rock slopes, foundations, and underground caverns.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106030"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077707","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 micro-macro fracture model for evaluating the brittle-ductile transition and rockburst of rock in true triaxial compression","authors":"Xiaozhao Li,&nbsp;Lianjie Li,&nbsp;Yujie Yan,&nbsp;Chengzhi Qi","doi":"10.1016/j.ijrmms.2024.105993","DOIUrl":"10.1016/j.ijrmms.2024.105993","url":null,"abstract":"<div><div>In deep underground engineering, true triaxial compressive stress and internal microcrack characteristics significantly influence the brittle-ductile transition and anisotropic mechanical behavior of rock, thereby affecting the engineering life cycle. However, current research on the micro-macro mechanical model under true triaxial compressive stress, particularly regarding the rock's brittle-ductile transition and anisotropic damage, is extremely limited. This paper aims to propose a macro-micromechanical model to describe the aforementioned physical and mechanical properties of rocks. The model introduces a lateral stress function into the micro-macro damage formula and derives the axial stress-strain relationship during crack propagation by incorporating the stress-crack length relationship under true triaxial stress. By considering the stress effects on the effective elastic modulus and nominal Poisson's ratio, the lateral stress-strain relationship is derived, resulting in a complete stress-strain curve. Finally, based on the relationships between triaxial principal strains, elastic deformation and triaxial principal stresses, the relationships between rock volumetric strain, crack volumetric strain, and triaxial principal stress are separately established. The influence of lateral principal stress on characteristic stresses is analyzed. The resulting model is combined with the brittleness evaluation index and the residual elastic energy index, respectively, to analyze the effects of micro parameters and principal stresses on brittleness and rockburst proneness. A comparative analysis of the similarities and differences between brittleness and rockburst proneness is conducted, revealing a positive correlation between the ratio of residual elastic energy and the post-peak to pre-peak brittleness index, expressed as <span><math><mrow><msub><mi>C</mi><mtext>EF</mtext></msub><mo>∝</mo><msub><mi>B</mi><mrow><mi>i</mi><mn>2</mn></mrow></msub><mo>/</mo><msub><mi>B</mi><mrow><mi>i</mi><mn>1</mn></mrow></msub></mrow></math></span>. The proposed model theoretically addresses the issues of brittle-ductile transition and anisotropic damage under true triaxial conditions. It can also be applied to explain and predict rockburst proneness.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 105993"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825395","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":"Analytical solutions of two-liner tunnels constructed in time-dependent plastic rocks considering loading-unloading stress paths","authors":"Hua-ning Wang ,&nbsp;Qian Liu ,&nbsp;Fei Song ,&nbsp;Rui-cong Fu ,&nbsp;Ming-jing Jiang","doi":"10.1016/j.ijrmms.2024.106017","DOIUrl":"10.1016/j.ijrmms.2024.106017","url":null,"abstract":"<div><div>The mechanical behaviours of soft rocks are time-dependent and significantly influenced by the loading and unloading histories. The main objective of this study is to investigate the tunnelling behaviours of supported tunnels constructed in time-dependent plastic geotechnical materials, taking into account the tunnelling advancement, the viscoelastic-plastic behaviour of host rocks, sequentially installation of primary and secondary support systems, as well as the actual stress path throughout the entire excavation and construction stages. In the determination, the Burgers viscoelastic model and the unified strength theory respectively represent the time-dependency and plasticity of geotechnical materials. Furthermore, the interactions at both rock-support and support-support interfaces are considered. Finally, the time-dependent solutions of stresses, displacements, and supporting pressure are obtained, by using the compatibility and boundary conditions. As verification and validation steps, the results obtained from these solutions match well with numerical predictions and monitoring data. Finally, in the parametric analyses, the developed analytical solutions are performed to investigate the influence of the supporting time, and different material properties of host rocks and support systems on the stability of tunnels.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106017"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990459","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":"Anisotropic acoustoelastic effective-medium model for stress-dependent elastic moduli of fractured rocks","authors":"Bo-Ye Fu ,&nbsp;Li-Yun Fu","doi":"10.1016/j.ijrmms.2024.105979","DOIUrl":"10.1016/j.ijrmms.2024.105979","url":null,"abstract":"<div><div>Prestress significantly influences the mechanical properties of fractured rocks due to stress-induced anisotropy in the surrounding matrix and the stress-induced closure of cracks. Understanding the stress-dependent elastic moduli and anisotropic properties is crucial for various geoscience applications. The theory of acoustoelasticity only accounts for weak nonlinear elasticity with finite strains through the third-order elastic constants (3oECs) that are strictly valid for an isotropic homogeneous medium. Incorporating the David-Zimmerman (DZ) and Mori-Tanaka (MT) models into the theory of acoustoelasticity leads to an acoustoelastic DZ-MT model of fractured rocks. In this study, we extend the isotropic acoustoelastic DZ-MT model to address anisotropic conditions by examining two scenarios: one involving isotropic prestress applied to rocks with aligned cracks, and the other involving uniaxial prestress applied to rocks with isotropic cracks. The resulting anisotropic acoustoelastic DZ-MT model of fractured rocks is validated by experiment data measured from an artificial sample with aligned cracks and three isotropic sandstones (Massilon, Portland, and Berea). For the artificial sample, applying isotropic pressure will reduce the crack-induced anisotropy due to crack closure, leading in turn to increase the acoustoelastic effect on the background matrix as well as the effective elastic moduli of rocks. Aligned cracks primarily reduce the P-wave modulus for waves propagating perpendicular to the crack surfaces, making the P-wave modulus undergo significant changes because of its sensitivity to crack closure. For the natural sandstones with isotropic cracks subjected to uniaxial prestress, some existing cracks are closed, strongly depending on the relativity between crack orientation and loading direction. The P-wave modulus normal to the loading direction exhibits a slight increase, indicating the integrated effect of both acoustoelasticity and crack deformation. The complex microstructural changes in the case of uniaxial loading influence the application of acoustoelasticity and crack-closure model, potentially reducing the accuracy of the proposed DZ-MT model.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 105979"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142793153","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":"Deterioration mechanisms of coal mechanical properties under uniaxial multi-level cyclic loading considering initial damage effects","authors":"Qican Ran ,&nbsp;Yunpei Liang ,&nbsp;Zhili Yang ,&nbsp;Quanle Zou ,&nbsp;Chunfeng Ye ,&nbsp;Chenglin Tian ,&nbsp;Zhaopeng Wu ,&nbsp;Bichuan Zhang ,&nbsp;Weizhi Wang","doi":"10.1016/j.ijrmms.2024.106006","DOIUrl":"10.1016/j.ijrmms.2024.106006","url":null,"abstract":"<div><div>With the increase in global energy demand, coal remains a vital energy resource. However, during coal mining, coal often experiences both initial damage and cyclic loading, which leads to the deterioration of its mechanical properties. In this study, uniaxial multi-level cyclic loading experiments were performed on initial damage coal specimens (IDCSs) to examine their deformation evolution, energy characteristics, acoustic emission (AE) characteristics, and internal fracture distribution. The results indicate that a higher degree of initial damage leads to a shorter fatigue life of IDCSs, a more significant reduction in strength, and a noticeable decline in the deformation modulus. This indicated that the internal microfractures in the high IDCSs were more fully developed, leading to a reduction of the effective bearing area, an increase in the linear energy dissipation capacity, and the percentage of dissipated energy. Meanwhile, the AE characteristics revealed intense large-scale fracture extension in the coal specimens with higher initial damage, lower AE <em>b</em> -values, and an increased percentage of shear cracks. The spatial and temporal distribution of AE events demonstrated a positive correlation with initial damage. The AE signal parameters of IDCSs exhibited multifractal characteristics, further indicating a more complex failure mode in highly damaged specimens. Additionally, the three-dimensional fracture volume percentage and fractal dimension, which are quantitative measures of internal fractures, also increased with initial damage. Meanwhile, localized areas of high IDCSs were more likely to form domino structures. Ultimately, the macroscopic and microscopic deterioration mechanisms of coal's mechanical properties under the combined influence of initial damage and cyclic loading were revealed. The interaction of initial damage and cyclic loading accelerated the expansion of internal pores and microfractures, reduced inter-particle forces, and significantly deteriorated the coal's mechanical properties. This study enhances the understanding of the deterioration mechanisms in IDCSs and provides a scientific basis for coal mine disaster prevention.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106006"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901912","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":"Carbon negative backfill mining in coal mines for carbon neutralization: Chemical carbon fixation performances with mineralized gangue","authors":"Jixiong Zhang ,&nbsp;Baiyi Li ,&nbsp;Yachen Xie ,&nbsp;Cunbao Li ,&nbsp;Nan Zhou ,&nbsp;Yuming Guo ,&nbsp;Zejun Li ,&nbsp;Heping Xie","doi":"10.1016/j.ijrmms.2024.106016","DOIUrl":"10.1016/j.ijrmms.2024.106016","url":null,"abstract":"<div><div>Safe, efficient, and low-carbon coal mining is vital, especially for China, where coal remains the main energy source. Minimizing rockburst risks and ecological damage, as well as developing low, zero, and carbon negative mining, become the main task of the coal industry. However, their realization is hindered by the increasing accumulation of by-products of coal mining and utilization, such as abundant gangue, fly ash, coal-based solid waste, and CO₂. To mitigate these problems, the current study focuses on carbon negative backfill mining (CNBM), proposing two CNBM approaches: (i) physical carbon fixation with high-porosity gangue and (ii) chemical carbon fixation with mineralized gangue. To this end, a sealed carbon fixation stirred autoclave was designed for experiments on solid waste gangue, and results were analyzed to reveal the effects of stirring rate, reaction temperature, CO₂ pressure, and solid-liquid ratio on carbon fixation performance. The gangue under study had carbon fixation potential, with a theoretical maximum carbon fixation capacity of 10.17 g/kg. Carbon fixation capacity and carbonation degree were positively related to stirring rate and pressure, being negatively related to temperature and solid-liquid ratio. Noteworthy that CO₂ pressure, which had the highest correlation with carbon fixation capacity, was classified into a group of “smooth-influencing factors”. In contrast, temperature and solid-liquid ratio were considered “abrupt-influencing factors”, which should be finely adjusted to avoid sharp deterioration of carbon fixation capacity. Finally, the main challenges faced by CNBM were summarized, and potential research directions for backfill mining under carbon fixation were discussed, including CO₂ migration and fixation mechanism, collaboration between filling body and CO₂, surface activation of coal-based solid waste, CO₂-related accelerated mineralization approaches, as well as safe and efficient CO₂ transport approaches.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106016"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142929217","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":"Charge signals characterizing the influence of bedding angles on shale damage under cyclic loading and unloading","authors":"Long Ren ,&nbsp;Baolong Zhu ,&nbsp;Jing Li ,&nbsp;Liming Qiu","doi":"10.1016/j.ijrmms.2024.106001","DOIUrl":"10.1016/j.ijrmms.2024.106001","url":null,"abstract":"<div><div>The role of bedding angle on the mechanic properties and failure modes of shale under cyclic loading and unloading conditions is unclear. This study conducted uniaxial cyclic loading and unloading tests on shales from the Longmaxi Formation with different bedding angles (<em>θ</em> = 0°, 22.5°, 45°, 67.5° and 90°), and characterized their damage evolution through both AE and charge signals. Results show that the compressive strengths are higher, and the loading cycles are more in specimens with <em>θ</em> = 0° and 90° than those with <em>θ</em> = 22.5°, 45° and 67.5° during cyclic loading tests, resulting in a silent period of signaling presented in former but not in latter <em>θ</em>. Both AE and charge signals can well reflect the major damages in time-domain analysis, while only charge signals can characterize the minor damages at the silent stages by continuous wavelet transforming into time-frequency plots, leading to their advantages in characterizing the damage evolution in specimens with <em>θ</em> = 0° and 90°, but not with <em>θ</em> = 22.5°, 45° and 67.5°. These differences can be attributed to their different signal acquirement mechanisms. These findings highlight the effectiveness of charge signals in characterizing the shale damage evolution under loading and unloading conditions.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":"186 ","pages":"Article 106001"},"PeriodicalIF":7.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825390","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}