Pub Date : 2026-01-01Epub Date: 2025-08-22DOI: 10.1016/j.rockmb.2025.100238
Yiming Gu , Zhe Li , Yun Chen , Yuliang Zhang
High-temperature damage in rocks significantly affects ultrasonic amplitude attenuation. Inverting rock damage through amplitude attenuation offers a rapid, non-destructive, and convenient detection method. However, the single-frequency ultrasonic testing method, due to its single amplitude attenuation parameter and relatively large experimental error, is difficult to fully reflect the material's characteristics, ultrasonic flaw detection methods based on multi-frequency amplitude attenuation are relatively scarce. To address this, the study proposes a multi-frequency ultrasonic amplitude attenuation detection method, eliminating single-frequency measurement errors and accurately characterizing the attenuation behavior of thermally damaged rocks. Experimental results show that after high-temperature treatment, P-wave amplitude attenuation increases progressively with frequency (by 50%), whereas S-wave attenuation first decreases and then rises. A correlation model between amplitude attenuation and damage variables was established, confirming that P-wave attenuation effectively quantifies rock damage. The study initially explored the interaction mechanism between multi-frequency ultrasonic and fractures: low-frequency waves exhibit increased attenuation due to boundary reflections, while high-frequency waves show enhanced attenuation as diffraction effects weaken. These findings bridge a critical gap in multi-frequency amplitude attenuation research and provide a scientific basis for identifying high-temperature damage in rocks.
{"title":"A multi-frequency ultrasonic amplitude attenuation method for identifying damage of rock","authors":"Yiming Gu , Zhe Li , Yun Chen , Yuliang Zhang","doi":"10.1016/j.rockmb.2025.100238","DOIUrl":"10.1016/j.rockmb.2025.100238","url":null,"abstract":"<div><div>High-temperature damage in rocks significantly affects ultrasonic amplitude attenuation. Inverting rock damage through amplitude attenuation offers a rapid, non-destructive, and convenient detection method. However, the single-frequency ultrasonic testing method, due to its single amplitude attenuation parameter and relatively large experimental error, is difficult to fully reflect the material's characteristics, ultrasonic flaw detection methods based on multi-frequency amplitude attenuation are relatively scarce. To address this, the study proposes a multi-frequency ultrasonic amplitude attenuation detection method, eliminating single-frequency measurement errors and accurately characterizing the attenuation behavior of thermally damaged rocks. Experimental results show that after high-temperature treatment, P-wave amplitude attenuation increases progressively with frequency (by 50%), whereas S-wave attenuation first decreases and then rises. A correlation model between amplitude attenuation and damage variables was established, confirming that P-wave attenuation effectively quantifies rock damage. The study initially explored the interaction mechanism between multi-frequency ultrasonic and fractures: low-frequency waves exhibit increased attenuation due to boundary reflections, while high-frequency waves show enhanced attenuation as diffraction effects weaken. These findings bridge a critical gap in multi-frequency amplitude attenuation research and provide a scientific basis for identifying high-temperature damage in rocks.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"5 1","pages":"Article 100238"},"PeriodicalIF":7.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The failure of support systems in deep coal mine roadways is a critical issue that hinders the development of deep coal resources. As a critical support element, the surface retaining element (SRE) plays a more prominent role in deep conditions. A comprehensive investigation into the anti-impact mechanism of an SRE on bolted surrounding rock under a dynamic load is greatly needed. In this study, split Hopkinson pressure bar (SHPB) tests were conducted to investigate the strengthening effect of different SRE areas on the mechanical properties of bolted specimens under dynamic and static loading. Moreover, the reinforcement effect of the SRE on the surrounding rock under various dynamic loadings was examined by FLAC3D. The results indicate that increasing the SRE area enhances the overall mechanical properties of the bolted specimens under combined dynamic and static loading conditions. By constructing an engineering-scale roadway numerical model, the impact of the SRE area on the amount of roof subsidence increases with increasing dynamic loading. The research findings enrich the study of the bearing capacity of SREs on bolted surrounding rock and provide a theoretical basis for controlling the surrounding rock in deep dynamic load roadways.
{"title":"Research on the effect of surface retaining elements on the dynamic load resistance of bolted rock","authors":"Hao Feng , Lishuai Jiang , Qingjia Niu , Chunang Li , Atsushi Sainoki","doi":"10.1016/j.rockmb.2025.100214","DOIUrl":"10.1016/j.rockmb.2025.100214","url":null,"abstract":"<div><div>The failure of support systems in deep coal mine roadways is a critical issue that hinders the development of deep coal resources. As a critical support element, the surface retaining element (SRE) plays a more prominent role in deep conditions. A comprehensive investigation into the anti-impact mechanism of an SRE on bolted surrounding rock under a dynamic load is greatly needed. In this study, split Hopkinson pressure bar (SHPB) tests were conducted to investigate the strengthening effect of different SRE areas on the mechanical properties of bolted specimens under dynamic and static loading. Moreover, the reinforcement effect of the SRE on the surrounding rock under various dynamic loadings was examined by FLAC3D. The results indicate that increasing the SRE area enhances the overall mechanical properties of the bolted specimens under combined dynamic and static loading conditions. By constructing an engineering-scale roadway numerical model, the impact of the SRE area on the amount of roof subsidence increases with increasing dynamic loading. The research findings enrich the study of the bearing capacity of SREs on bolted surrounding rock and provide a theoretical basis for controlling the surrounding rock in deep dynamic load roadways.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"5 1","pages":"Article 100214"},"PeriodicalIF":7.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-07-10DOI: 10.1016/j.rockmb.2025.100220
Chunguang Wang , Ji Wang , Zhigang Tao , Manchao He , Haichao Liu , Shuai Li , Zhiyou Gao , Guojie Liang
How to determine reduction strategy between cohesion (c) and internal friction angle (ϕ) is crucial for slope stability evaluation using the dual-strength reduction method (DSRM). Given that the slope sliding evolution is recognized as a dynamically mechanical system, interaction between sliding mass and sliding bed is governed by minimization of the action, which is consistent with minimum factor of safety of Pan's Extremum Principle. This study introduces an improved dual-strength reduction method by using Hill Climbing Algorithm to determine reduction strategy for the dual-strength parameters. Through employing this approach to analyze the stability of an embankment slope under unsaturated steady seepage, the reduction path of dual-strength parameters is obtained. It is found that the internal friction angle degrades preferentially during the transition from stable state to critical state, followed by the cohesion degradation. The results are in agreement with the rate-and-state friction law. Pore water pressure can reduce frictional resistance, leading to greater degradation of friction angle at critical state. Conversely, the water-rock softening effect can lead to a smaller reduction in the friction angle than in cohesion. This method can provide a new insight into developing dual-strength parameters reduction strategy for the slope stability analysis.
{"title":"An improved dual-strength reduction method of slope stability analysis using Hill Climbing Algorithm","authors":"Chunguang Wang , Ji Wang , Zhigang Tao , Manchao He , Haichao Liu , Shuai Li , Zhiyou Gao , Guojie Liang","doi":"10.1016/j.rockmb.2025.100220","DOIUrl":"10.1016/j.rockmb.2025.100220","url":null,"abstract":"<div><div>How to determine reduction strategy between cohesion (<em>c</em>) and internal friction angle (<em>ϕ</em>) is crucial for slope stability evaluation using the dual-strength reduction method (DSRM). Given that the slope sliding evolution is recognized as a dynamically mechanical system, interaction between sliding mass and sliding bed is governed by minimization of the action, which is consistent with minimum factor of safety of Pan's Extremum Principle. This study introduces an improved dual-strength reduction method by using Hill Climbing Algorithm to determine reduction strategy for the dual-strength parameters. Through employing this approach to analyze the stability of an embankment slope under unsaturated steady seepage, the reduction path of dual-strength parameters is obtained. It is found that the internal friction angle degrades preferentially during the transition from stable state to critical state, followed by the cohesion degradation. The results are in agreement with the rate-and-state friction law. Pore water pressure can reduce frictional resistance, leading to greater degradation of friction angle at critical state. Conversely, the water-rock softening effect can lead to a smaller reduction in the friction angle than in cohesion. This method can provide a new insight into developing dual-strength parameters reduction strategy for the slope stability analysis.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"5 1","pages":"Article 100220"},"PeriodicalIF":7.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-06-06DOI: 10.1016/j.rockmb.2025.100213
Jie Zhou , Chengjun Liu , Chao Ban , Zhenming Shi , Junjie Ren , Huade Zhou , Zhong Liu , Yiqun Tang
The shear strength of cemented soil-soil interface is affected by the size effect of experimental sample. With the advancing density of urban underground space and the wide application of grouting reinforcement for adjacent underground structures, the inaccurate interface strength results due to size effects are receiving increasing attention. This study conducted different scaled interface shear tests and numerical simulation to evaluate the influence of size effect on the cemented soil-soil shear strength. In large scale interface shear experiments, the shear stress increased with the accumulation of shear displacement in two stages and finally stabilized at interface shear strength. But in small scale direct shear tests, interface shear stress dropped after reaching a much higher interface shear strength. With the increasing of sample size, the interface shear strength gradually reduced to a stable value. This relation was analyzed and the characteristic sample size for interface unaffected by size effect was determined, which, for cuboid sample, is 300 mm. The relation of the cemented soil-soil interface shear strength from commonly used direct shear sample and sample with characteristics size was concluded by a series of comparative experiments. By analyzing the failure properties of cemented soil-soil agglutinate layer and the displacement pattern of material grains, the internal mechanism of size effect on cemented soil-soil interface were proposed. The conclusions can advance the accurate acquisition of cemented soil-soil interface, provide references to the unification of research achievements with different sample size, and give recommendations to the standard interface shear experimental method in the future.
{"title":"Cemented soil-soil interface shear strength evaluation I: Size effect and characteristic experimental size quantization","authors":"Jie Zhou , Chengjun Liu , Chao Ban , Zhenming Shi , Junjie Ren , Huade Zhou , Zhong Liu , Yiqun Tang","doi":"10.1016/j.rockmb.2025.100213","DOIUrl":"10.1016/j.rockmb.2025.100213","url":null,"abstract":"<div><div>The shear strength of cemented soil-soil interface is affected by the size effect of experimental sample. With the advancing density of urban underground space and the wide application of grouting reinforcement for adjacent underground structures, the inaccurate interface strength results due to size effects are receiving increasing attention. This study conducted different scaled interface shear tests and numerical simulation to evaluate the influence of size effect on the cemented soil-soil shear strength. In large scale interface shear experiments, the shear stress increased with the accumulation of shear displacement in two stages and finally stabilized at interface shear strength. But in small scale direct shear tests, interface shear stress dropped after reaching a much higher interface shear strength. With the increasing of sample size, the interface shear strength gradually reduced to a stable value. This relation was analyzed and the characteristic sample size for interface unaffected by size effect was determined, which, for cuboid sample, is 300 mm. The relation of the cemented soil-soil interface shear strength from commonly used direct shear sample and sample with characteristics size was concluded by a series of comparative experiments. By analyzing the failure properties of cemented soil-soil agglutinate layer and the displacement pattern of material grains, the internal mechanism of size effect on cemented soil-soil interface were proposed. The conclusions can advance the accurate acquisition of cemented soil-soil interface, provide references to the unification of research achievements with different sample size, and give recommendations to the standard interface shear experimental method in the future.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"4 4","pages":"Article 100213"},"PeriodicalIF":7.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-05-12DOI: 10.1016/j.rockmb.2025.100211
Hongjun Lu , Yin Qi , Wenbin Chen , Chuan Li , Xuefeng Li
The coupling effect of temperature and confining pressure on fracture toughness is a critical issue in deep shale gas development that cannot be overlooked. Field and laboratory studies have shown that this coupling effect significantly alters shale fracture toughness, but the underlying mechanisms of it remain poorly understood. To investigate the mechanisms of the temperature-pressure coupling effect on the fracture toughness of transversely isotropic shale, this study develops a thermal-mechanical DEM (discrete element method) model that integrates a customized thermal algorithm and a shining-lamp algorithm. The model validity is verified by using experimental results from high-temperature SCB (semi-circular bend) tests. Additionally, a series of SCB tests under different temperatures and confining pressures are simulated based on this model. The loading curves, fracture toughness evolution, crack morphology, and microcrack statistics results obtained from simulations are analyzed to provide insights into the mechanisms of the temperature-pressure coupling effect. The simulation results indicate that the stimulation of thermal-induced microcracks on crack propagation may be the primary microscopic mechanism behind the thermal-induced weakening of shale fracture toughness. Meanwhile, confining pressure has an inhibitory influence on the thermal effect of shale fracture toughness. The activation of shear microcracks under the application of confining pressure is identified as the leading microscopic mechanism of confining pressure inhibition. The findings in this study enhance the understanding of the fracture property evolution of deep shale reservoirs and provide guidance for site selection, engineering design, and reservoir stability assessment in deep shale gas development.
{"title":"Coupling effect of temperature and confining pressure on fracture toughness of transversely isotropic shale: Insights from a thermal-mechanical DEM model","authors":"Hongjun Lu , Yin Qi , Wenbin Chen , Chuan Li , Xuefeng Li","doi":"10.1016/j.rockmb.2025.100211","DOIUrl":"10.1016/j.rockmb.2025.100211","url":null,"abstract":"<div><div>The coupling effect of temperature and confining pressure on fracture toughness is a critical issue in deep shale gas development that cannot be overlooked. Field and laboratory studies have shown that this coupling effect significantly alters shale fracture toughness, but the underlying mechanisms of it remain poorly understood. To investigate the mechanisms of the temperature-pressure coupling effect on the fracture toughness of transversely isotropic shale, this study develops a thermal-mechanical DEM (discrete element method) model that integrates a customized thermal algorithm and a shining-lamp algorithm. The model validity is verified by using experimental results from high-temperature SCB (semi-circular bend) tests. Additionally, a series of SCB tests under different temperatures and confining pressures are simulated based on this model. The loading curves, fracture toughness evolution, crack morphology, and microcrack statistics results obtained from simulations are analyzed to provide insights into the mechanisms of the temperature-pressure coupling effect. The simulation results indicate that the stimulation of thermal-induced microcracks on crack propagation may be the primary microscopic mechanism behind the thermal-induced weakening of shale fracture toughness. Meanwhile, confining pressure has an inhibitory influence on the thermal effect of shale fracture toughness. The activation of shear microcracks under the application of confining pressure is identified as the leading microscopic mechanism of confining pressure inhibition. The findings in this study enhance the understanding of the fracture property evolution of deep shale reservoirs and provide guidance for site selection, engineering design, and reservoir stability assessment in deep shale gas development.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"4 4","pages":"Article 100211"},"PeriodicalIF":7.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-06-19DOI: 10.1016/j.rockmb.2025.100216
Yunpeng Guo , Dongqiao Liu , Jieyu Li , Jian Liu , Xiao Tong
The damage process is categorized into two phases from the perspective of crack evolution, damage recovery induced by the closure of primary cracks and damage growth induced by the propagation of new cracks, to establish a damage evolution equation and constitutive relationship that accounts for the initial damage recovery characteristics of rocks. The damage recovery and growth variables are determined through coordinate transformation and the deformation modulus attenuation method, using the damage stress threshold as the critical point. The corresponding theoretical damage evolution equation is developed using the logistic model. In addition, based on the strain equivalence hypothesis, a comprehensive damage evolution equation and constitutive model incorporating the rock's initial compaction process are developed. Finally, the validity of the proposed model is confirmed using uniaxial compression data from gabbro, granite, red sandstone, and yellow sandstone. The results show that the model curve closely aligns with the experimental data.
{"title":"A logistic-based constitutive model for rocks under uniaxial compression considering the initial damage recovery characteristics","authors":"Yunpeng Guo , Dongqiao Liu , Jieyu Li , Jian Liu , Xiao Tong","doi":"10.1016/j.rockmb.2025.100216","DOIUrl":"10.1016/j.rockmb.2025.100216","url":null,"abstract":"<div><div>The damage process is categorized into two phases from the perspective of crack evolution, damage recovery induced by the closure of primary cracks and damage growth induced by the propagation of new cracks, to establish a damage evolution equation and constitutive relationship that accounts for the initial damage recovery characteristics of rocks. The damage recovery and growth variables are determined through coordinate transformation and the deformation modulus attenuation method, using the damage stress threshold as the critical point. The corresponding theoretical damage evolution equation is developed using the logistic model. In addition, based on the strain equivalence hypothesis, a comprehensive damage evolution equation and constitutive model incorporating the rock's initial compaction process are developed. Finally, the validity of the proposed model is confirmed using uniaxial compression data from gabbro, granite, red sandstone, and yellow sandstone. The results show that the model curve closely aligns with the experimental data.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"4 4","pages":"Article 100216"},"PeriodicalIF":7.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-05-17DOI: 10.1016/j.rockmb.2025.100210
Jinxuan Li , Songfeng Guo , Guoxiang Yang , Shengwen Qi
Tensile strength is a crucial parameter for assessing rock stability and fracture characteristics, which play a significant role in the prediction and engineering design of geohazards. However, fault slip activity can weaken the strength of the surrounding rock mass, thereby influencing its mechanical behavior and failure mode. This study investigates the spatial variation of the tensile strength (σt), compressive strength (σc), P-wave velocity (Vp), and acoustic emission (AE) characteristics at varying distances from the Xianshuihe Fault zone (XSHF), focusing on three representative profiles. The results show that the σt, σc, and Vp significantly decrease near the fault (0–5 km). Specifically, the relative change rates of σt, σc, and Vp at approximately 5 km from the fault are 1.55–1.8 times, 1.22–1.86 times, and 1.02–1.25 times greater, respectively, compared to the near-fault zone. As the distance from the fault increases (10–20 km), the rock integrity improves, and the mechanical properties recover. AE monitoring reveals increased microcracks near the fault, with higher b-value and dominant tensile failure modes. Further from the fault, the rock exhibits increased brittleness, and tensile cracking becomes more prevalent. Overall, the mechanical parameters and AE characteristics demonstrate predictable spatial variation with distance, providing valuable insights for identifying stress concentration zones and potential geohazards.
{"title":"The influence of faults on adjacent rock mechanical behavior and acoustic emission characteristics: A case study of the xianshuihe fault zone","authors":"Jinxuan Li , Songfeng Guo , Guoxiang Yang , Shengwen Qi","doi":"10.1016/j.rockmb.2025.100210","DOIUrl":"10.1016/j.rockmb.2025.100210","url":null,"abstract":"<div><div>Tensile strength is a crucial parameter for assessing rock stability and fracture characteristics, which play a significant role in the prediction and engineering design of geohazards. However, fault slip activity can weaken the strength of the surrounding rock mass, thereby influencing its mechanical behavior and failure mode. This study investigates the spatial variation of the tensile strength (<em>σ</em><sub>t</sub>), compressive strength (<em>σ</em><sub>c</sub>), P-wave velocity (<em>V</em><sub>p</sub>), and acoustic emission (AE) characteristics at varying distances from the Xianshuihe Fault zone (XSHF), focusing on three representative profiles. The results show that the <em>σ</em><sub>t</sub>, <em>σ</em><sub>c</sub>, and <em>V</em><sub>p</sub> significantly decrease near the fault (0–5 km). Specifically, the relative change rates of <em>σ</em><sub>t</sub>, <em>σ</em><sub>c</sub>, and <em>V</em><sub>p</sub> at approximately 5 km from the fault are 1.55–1.8 times, 1.22–1.86 times, and 1.02–1.25 times greater, respectively, compared to the near-fault zone. As the distance from the fault increases (10–20 km), the rock integrity improves, and the mechanical properties recover. AE monitoring reveals increased microcracks near the fault, with higher <em>b</em>-value and dominant tensile failure modes. Further from the fault, the rock exhibits increased brittleness, and tensile cracking becomes more prevalent. Overall, the mechanical parameters and AE characteristics demonstrate predictable spatial variation with distance, providing valuable insights for identifying stress concentration zones and potential geohazards.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"4 4","pages":"Article 100210"},"PeriodicalIF":7.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-06-21DOI: 10.1016/j.rockmb.2025.100215
Jiong Wang , Jian Jiang , Yiwen Chang , Haosen Wang , Lei Ma , Manchao He , Peng Liu , Siyu Wang
The study investigates the mechanical properties of 1G-NPR (Negative Poisson's Ratio) cable-anchored sandstone under uniaxial compression, employing Acoustic Emission (AE) and Digital Image Correlation (DIC) methods to analyze deformation and fracture behavior. The research aims to provide insights into the failure mechanisms of rock anchored with 1G-NPR cables and their potential applications in engineering practices. A comparative analysis was performed on three anchoring methods—unanchored, conventional cable-anchored, and 1G-NPR cable anchored—under both lateral confinement and unconfined conditions during uniaxial compression. Results show that rock specimens anchored with 1G-NPR cables exhibit significantly higher uniaxial compressive strength compared to unanchored and conventional cable-anchored specimens. The 1G-NPR cables provide constant resistance at peak stress, followed by a stepped decrease in post-peak bearing capacity. Under lateral confinement, AE events are minimal in the early stage and become concentrated during the unstable crack propagation phase, accounting for around 75% of cumulative AE events. This phase features a pronounced AE activity peak at a strain level of 5.24 × 10−3, the highest among the six test groups. Post-failure analysis reveals that 1G-NPR cable-anchored rock exhibits the lowest degree of fragmentation, with cracks not extending through the cable position, indicating that failure did not penetrate the cable-anchored zone. Lateral confinement aids in restricting strain concentration along the anchoring direction. DIC analysis of principal strain fields further indicates that horizontal displacement zones in 1G-NPR cable-anchored specimens emerge at 0.6Pmax at a later stage than in other groups, suggesting that these cables effectively control crack formation and propagation within the rock mass. Findings highlight the effectiveness of 1G-NPR cables in enhancing rock strength, limiting failure, and managing large deformations, thereby playing a critical role in stabilizing surrounding rock under high-ground stress in engineering applications.
{"title":"Experimental study on the mechanical properties of 1G-NPR cable anchored rock with AE-DIC method","authors":"Jiong Wang , Jian Jiang , Yiwen Chang , Haosen Wang , Lei Ma , Manchao He , Peng Liu , Siyu Wang","doi":"10.1016/j.rockmb.2025.100215","DOIUrl":"10.1016/j.rockmb.2025.100215","url":null,"abstract":"<div><div>The study investigates the mechanical properties of 1G-NPR (Negative Poisson's Ratio) cable-anchored sandstone under uniaxial compression, employing Acoustic Emission (AE) and Digital Image Correlation (DIC) methods to analyze deformation and fracture behavior. The research aims to provide insights into the failure mechanisms of rock anchored with 1G-NPR cables and their potential applications in engineering practices. A comparative analysis was performed on three anchoring methods—unanchored, conventional cable-anchored, and 1G-NPR cable anchored—under both lateral confinement and unconfined conditions during uniaxial compression. Results show that rock specimens anchored with 1G-NPR cables exhibit significantly higher uniaxial compressive strength compared to unanchored and conventional cable-anchored specimens. The 1G-NPR cables provide constant resistance at peak stress, followed by a stepped decrease in post-peak bearing capacity. Under lateral confinement, AE events are minimal in the early stage and become concentrated during the unstable crack propagation phase, accounting for around 75% of cumulative AE events. This phase features a pronounced AE activity peak at a strain level of 5.24 × 10<sup>−3</sup>, the highest among the six test groups. Post-failure analysis reveals that 1G-NPR cable-anchored rock exhibits the lowest degree of fragmentation, with cracks not extending through the cable position, indicating that failure did not penetrate the cable-anchored zone. Lateral confinement aids in restricting strain concentration along the anchoring direction. DIC analysis of principal strain fields further indicates that horizontal displacement zones in 1G-NPR cable-anchored specimens emerge at 0.6P<sub>max</sub> at a later stage than in other groups, suggesting that these cables effectively control crack formation and propagation within the rock mass. Findings highlight the effectiveness of 1G-NPR cables in enhancing rock strength, limiting failure, and managing large deformations, thereby playing a critical role in stabilizing surrounding rock under high-ground stress in engineering applications.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"4 4","pages":"Article 100215"},"PeriodicalIF":7.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144860435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reliable stability assessment requires an objective and precise assessment of the rock mass quality classification. A deep learning model is developed to create a tool that can provide a rapid and precise assessment of the quality of rock masses. While there are empirical equations to determine RMR values from Q parameters, this study provides an advanced highly accurate deep learning approach to determine RMR values from Q parameters. This serves to reduce the amount of fieldwork related to collecting the rockmass data needed to independently assess rockmass quality using the RMR system and the Q system separately. The RMR values, like Q values, were first determined independently in the field. The deep learning approach was later used to predict the field-determined RMR values from the field-determined Q parameters. This means that each practical field measurement point had an RMR, and a Q value independently determined for it before the deep learning approach was applied. The six rockmass parameters of the Q system (RQD, Jn, Jr, Ja, Jw, SRF) are used as input in this model while the RMR is used as the output variable. In this study, the dataset contains 356 samples, 70%, 15% and 15% of the entire sample data are used to train, test, and validate the model, respectively. The predictive performance of the models was evaluated and compared using metrics such as R2, MAE, and RMSE among many others. The overall R2 values for the ANN, FDA-ANN and SCA-ANN are 0.9951, 0.996 and 0.9955 respectively. The MAE values are 0.099, 0.096 and 0.085 for ANN, FDA-ANN and SCA-ANN respectively. The FDA-ANN model has a higher accuracy than other techniques, such as the ANN and SCA-ANN. The error values obtained for each of the models are very close to their expected value of 0 while their obtained R2 and VAF are also much closer to the targeted value of 1 and 100% respectively. The PI is also close to the expected value of 2. Hence, the three proposed models can be confidently used in predicting RMR values using Q parameters obtained from field investigations without the need to independently determine RMR from the traditional RMR field parameters. The study used the Chord diagram to display the rank of the performance indicators and the sensitivity analysis using the Cosine Amplitude methods (CAM). It shows that the RQD parameter has the highest CAM value followed by Jw and then Jn for all three models. The results offered here provide insight for engineers and academics who are interested in analysing rock mass classification criteria or conducting field investigations.
{"title":"Deep learning-powered rock mass classification: Predicting RMR from Q-system parameters with high accuracy","authors":"Tawanda Zvarivadza , Abiodun Ismail Lawal , Moshood Onifade , Francois Mulenga , Sangki Kwon , Manoj Khandelwal","doi":"10.1016/j.rockmb.2025.100219","DOIUrl":"10.1016/j.rockmb.2025.100219","url":null,"abstract":"<div><div>Reliable stability assessment requires an objective and precise assessment of the rock mass quality classification. A deep learning model is developed to create a tool that can provide a rapid and precise assessment of the quality of rock masses. While there are empirical equations to determine RMR values from Q parameters, this study provides an advanced highly accurate deep learning approach to determine RMR values from Q parameters. This serves to reduce the amount of fieldwork related to collecting the rockmass data needed to independently assess rockmass quality using the RMR system and the Q system separately. The RMR values, like Q values, were first determined independently in the field. The deep learning approach was later used to predict the field-determined RMR values from the field-determined Q parameters. This means that each practical field measurement point had an RMR, and a Q value independently determined for it before the deep learning approach was applied. The six rockmass parameters of the Q system (RQD, <em>J</em><sub><em>n</em></sub>, <em>J</em><sub><em>r</em></sub>, <em>J</em><sub><em>a</em></sub>, <em>J</em><sub><em>w</em></sub>, SRF) are used as input in this model while the RMR is used as the output variable. In this study, the dataset contains 356 samples, 70%, 15% and 15% of the entire sample data are used to train, test, and validate the model, respectively. The predictive performance of the models was evaluated and compared using metrics such as <em>R</em><sup>2</sup>, MAE, and RMSE among many others. The overall <em>R</em><sup>2</sup> values for the ANN, FDA-ANN and SCA-ANN are 0.9951, 0.996 and 0.9955 respectively. The MAE values are 0.099, 0.096 and 0.085 for ANN, FDA-ANN and SCA-ANN respectively. The FDA-ANN model has a higher accuracy than other techniques, such as the ANN and SCA-ANN. The error values obtained for each of the models are very close to their expected value of 0 while their obtained <em>R</em><sup>2</sup> and VAF are also much closer to the targeted value of 1 and 100% respectively. The PI is also close to the expected value of 2. Hence, the three proposed models can be confidently used in predicting RMR values using Q parameters obtained from field investigations without the need to independently determine RMR from the traditional RMR field parameters. The study used the Chord diagram to display the rank of the performance indicators and the sensitivity analysis using the Cosine Amplitude methods (CAM). It shows that the RQD parameter has the highest CAM value followed by <em>J</em><sub><em>w</em></sub> and then <em>J</em><sub><em>n</em></sub> for all three models. The results offered here provide insight for engineers and academics who are interested in analysing rock mass classification criteria or conducting field investigations.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"4 4","pages":"Article 100219"},"PeriodicalIF":7.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Blast-induced ground vibration (BIGV) is one of the detrimental environmental consequences of blasting operations in mining and civil engineering. Hence, accurate prediction of BIGV is highly imperative. Therefore, different novel artificial intelligence (AI) methods such as Bayesian regularized neural network (BRNN), Bayesian regularized causality-weighted neural network (BRCWNN) and Z-number-based Bayesian regularized causality-weighted neural network (Z-BRCWNN) are proposed in this study for the reliable prediction of BIGV in a dolomitic marble quarry using the obtained field data. The outcome of the proposed models is subjected to rigorous statistical analyses. The outcome of analyses revealed that the Z-BRCWNN model outperformed the other models with 70%, 82% and 82% threshold statistic values evaluated at the 5%, 10% and 15% confidence levels for the testing phase and 63%, 91% and 91% threshold values for the validation phase evaluated at the same levels as above. The sensitivity analysis conducted revealed that the distance from the measuring point to the blasting point (DI) has the highest influence on BIGV.
{"title":"Prediction of blast-induced ground vibration in dolomitic marble quarry using Z-number information and fuzzy cognitive map based neural network models","authors":"Shahab Hosseini , Abiodun Ismail Lawal , Francois Mulenga","doi":"10.1016/j.rockmb.2025.100217","DOIUrl":"10.1016/j.rockmb.2025.100217","url":null,"abstract":"<div><div>Blast-induced ground vibration (BIGV) is one of the detrimental environmental consequences of blasting operations in mining and civil engineering. Hence, accurate prediction of BIGV is highly imperative. Therefore, different novel artificial intelligence (AI) methods such as Bayesian regularized neural network (BRNN), Bayesian regularized causality-weighted neural network (BRCWNN) and Z-number-based Bayesian regularized causality-weighted neural network (Z-BRCWNN) are proposed in this study for the reliable prediction of BIGV in a dolomitic marble quarry using the obtained field data. The outcome of the proposed models is subjected to rigorous statistical analyses. The outcome of analyses revealed that the Z-BRCWNN model outperformed the other models with 70%, 82% and 82% threshold statistic values evaluated at the 5%, 10% and 15% confidence levels for the testing phase and 63%, 91% and 91% threshold values for the validation phase evaluated at the same levels as above. The sensitivity analysis conducted revealed that the distance from the measuring point to the blasting point (DI) has the highest influence on BIGV.</div></div>","PeriodicalId":101137,"journal":{"name":"Rock Mechanics Bulletin","volume":"4 4","pages":"Article 100217"},"PeriodicalIF":7.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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