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学者姓名:刘成禹
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A refined 3D numerical model was constructed to reflect the intricate topography, geological structures, and support conditions of the Yuanjue Cave in the Dazu Rock Carvings. The study identifies the main factors influencing the stability of the roof, the deformation and failure modes and key areas, and the current stage of the cave's stability was determined. The results show that the development of cavity depth acts as the trigger for roof deformation and failure, while the breakage of strip stones is the primary controlling factor. The overall deformation and failure mode of the roof is a combination of bending and torsion, with the key failure area located at the left front of the cave entrance. The current state of deformation in the cave's roof indicates it is in the mid-term accelerated change stage. These findings offer a reference for the stability analysis of other similarly complex caves.
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GB/T 7714 | Wu, Changyu , Liu, Chengyu , Yan, Shuming et al. Stability study of complex caves: a case study of Yuanjue Cave in the Dazu Rock Carvings [J]. | NPJ HERITAGE SCIENCE , 2025 , 13 (1) . |
MLA | Wu, Changyu et al. "Stability study of complex caves: a case study of Yuanjue Cave in the Dazu Rock Carvings" . | NPJ HERITAGE SCIENCE 13 . 1 (2025) . |
APA | Wu, Changyu , Liu, Chengyu , Yan, Shuming , Wang, Xugang . Stability study of complex caves: a case study of Yuanjue Cave in the Dazu Rock Carvings . | NPJ HERITAGE SCIENCE , 2025 , 13 (1) . |
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The presence of surface cracks in stone cultural relics can induce secondary deterioration pathologies, ultimately leading to surface exfoliation. Focusing on the petroglyphs in Damaidi, Northwest China, this study establishes a numerical model of rock mass containing surface cracks to investigate their mechanical impacts on petroglyph surfaces under two distinct mechanisms: thermal stress and water freezing within cracks. Furthermore, the influence of crack spacing on stress distribution and surface displacement was systematically examined. Key findings reveal that (1) Thermal stress induces new crack formation surrounding existing surface cracks; (2) Repeated thermal cycling leads to progressively denser crack networks; (3) When crack spacing reaches a critical threshold (<= 1.5 cm for Damaidi petroglyphs), frost heaving of interstitial water initiates granular disintegration; (4) Subsequent freeze-thaw cycles expand the affected areas, eventually causing scaling exfoliation. These mechanistic insights show excellent agreement with field documentation of crack patterns and exfoliation pathologies at the Damaidi site.
Keyword :
Crack spacing Crack spacing fissure water freezing fissure water freezing spalling spalling stone cultural heritage stone cultural heritage surface cracks surface cracks thermal stress thermal stress
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GB/T 7714 | Hu, Dong , Liu, Chengyu , Wu, Changyu et al. Surface Crack Hazards in Arid-Region Petroglyphs: Coupled Thermal and Freezing Effects from Northwest China [J]. | INTERNATIONAL JOURNAL OF ARCHITECTURAL HERITAGE , 2025 . |
MLA | Hu, Dong et al. "Surface Crack Hazards in Arid-Region Petroglyphs: Coupled Thermal and Freezing Effects from Northwest China" . | INTERNATIONAL JOURNAL OF ARCHITECTURAL HERITAGE (2025) . |
APA | Hu, Dong , Liu, Chengyu , Wu, Changyu , Wang, Jinhua . Surface Crack Hazards in Arid-Region Petroglyphs: Coupled Thermal and Freezing Effects from Northwest China . | INTERNATIONAL JOURNAL OF ARCHITECTURAL HERITAGE , 2025 . |
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In photovoltaic systems, the installation tilt angle of modules plays a critical role in determining both performance and economic returns. Existing methods for calculating the optimal tilt angle typically rely on complex solar radiation and anisotropic sky scattering models, which, despite their accuracy, involve intensive computational efforts. Based on the relationships between the proportion of direct radiation, latitude, and the optimal monthly tilt angle, this study proposed a method to calculate the monthly optimal tilt angle. Taking Zhangye City as an example, the accuracy and reliability of the proposed method were verified in comparison with the traditional method. Using this method, the monthly optimal tilt angles were calculated for three cities in China located at different latitudes, to reveal the annual variation patterns of these angles. The results showed that, at the same proportion of direct radiation, the monthly optimal tilt angle increases with latitude. Over the course of a year, the monthly optimal tilt angle first decreases and then increases. In low latitude cites, the monthly optimal tilt angle may even become negative.
Keyword :
calculation model calculation model fixed photovoltaic panel fixed photovoltaic panel monthly optimal tilt angle monthly optimal tilt angle proportion of direct radiation proportion of direct radiation
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GB/T 7714 | Zhang, Xiang-Xiang , Chen, Jia-Long , Dou, Hong-Qiang et al. CALCULATION MODEL FOR THE MONTHLY OPTIMAL TILT ANGLE OF FIXED PHOTOVOLTAIC PANELS [J]. | THERMAL SCIENCE , 2025 , 29 (2B) : 1403-1409 . |
MLA | Zhang, Xiang-Xiang et al. "CALCULATION MODEL FOR THE MONTHLY OPTIMAL TILT ANGLE OF FIXED PHOTOVOLTAIC PANELS" . | THERMAL SCIENCE 29 . 2B (2025) : 1403-1409 . |
APA | Zhang, Xiang-Xiang , Chen, Jia-Long , Dou, Hong-Qiang , Liu, Cheng-Yu , Hou, Xian-Ye . CALCULATION MODEL FOR THE MONTHLY OPTIMAL TILT ANGLE OF FIXED PHOTOVOLTAIC PANELS . | THERMAL SCIENCE , 2025 , 29 (2B) , 1403-1409 . |
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Liquid nitrogen (LN2) fracturing has been proposed to be used in unconventional gas engineering, including shale reservoirs. However, the effect of LN2 cooling on the fracture behaviors of bedding shale has not been well studied. In this study, three-point bending tests were conducted on shale samples at room temperature and under LN2 cooling condition, respectively. Different bedding angles were considered in these tests. The phenomenon of acoustic emission was monitored during the fracture initiation and propagation of bedding shale. The results showed that the tensile strength, fracture toughness, bending elastic modulus and fracture energy decreased with the increase of bedding angle under the same temperature condition, but the bedding angle has no significant effect on energy storage ratio and speed. There was a linear relationship between the tensile strength and fracture toughness of bedding shale. The crack initiation was inconsistent with the loading reference line except in 90 degrees bedding shale, and then turned to the direction parallel to the loading reference line, resulting in various fracture morphology of bedding shale. The acoustic emission signals were mainly concentrated in the failure stage because of the severe brittleness of bedding shale. Under LN2 cooling condition, the tensile strength, fracture toughness, bending elastic modulus, energy storage ratio, fracture energy and AE cumulative ringing counts of bedding shale with the same bedding angle significantly increased, but the energy storage speed decreased. The crack length along bedding direction was longer and the crack inflection point was clearer than those of bedding shale at room temperature.
Keyword :
Anisotropy Anisotropy Bedding shale Bedding shale Fracture behaviors Fracture behaviors Fracture toughness Fracture toughness Liquid-nitrogen Liquid-nitrogen Tensile strength Tensile strength Three-point bending test Three-point bending test
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GB/T 7714 | Zhang, Xiangxiang , Wu, Shaoyan , Liu, Chengyu et al. An experimental investigation into the effect of liquid nitrogen cooling on fracture behaviors of bedding shale [J]. | THEORETICAL AND APPLIED FRACTURE MECHANICS , 2025 , 136 . |
MLA | Zhang, Xiangxiang et al. "An experimental investigation into the effect of liquid nitrogen cooling on fracture behaviors of bedding shale" . | THEORETICAL AND APPLIED FRACTURE MECHANICS 136 (2025) . |
APA | Zhang, Xiangxiang , Wu, Shaoyan , Liu, Chengyu , Su, Shanjie . An experimental investigation into the effect of liquid nitrogen cooling on fracture behaviors of bedding shale . | THEORETICAL AND APPLIED FRACTURE MECHANICS , 2025 , 136 . |
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In Southwest China's high-temperature, humid, and rainy climate, ancient sandstone structures face significant deterioration due to acid rain and water accumulation, which cause dynamic and static dissolution. This degradation weakens the sandstone's physical and mechanical properties, threatening the preservation of cultural heritage sites. Dynamic dissolution is the process of matter and energy exchange during fluid-rock or fluid-mineral interactions under dynamic conditions. Under dynamic conditions, continuously renewed fluids supply chemicals for dissolution and remove dissolved products, sustaining reactions similar to acid rain dissolution. Static dissolution is the dissolution-erosion process between fluids and rocks or minerals in a relatively stationary fluid environment. Unlike dynamic dissolution, which involves moving fluids, static dissolution occurs in nearly stagnant fluids, where rising product concentrations from acid-rock reactions may hinder further dissolution, akin to static immersion dissolution. This study systematically examined how different dissolution conditions affect sandstone's pore structure, mechanical properties, and hygroscopic behavior. Nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM) were used to analyze pore structure changes, while ultrasonic testing and Leeb hardness measurements assessed mechanical strength. Hygroscopicity was evaluated through non-destructive moisture testing in controlled environments. The results show that dynamic dissolution has a greater impact on sandstone than static dissolution. Both conditions increased porosity in two stages, but dynamic dissolution enhanced pore connectivity while static dissolution caused gradual porosity growth and localized cracks. Dynamic dissolution significantly reduced surface hardness and P-wave velocity, increasing hardness heterogeneity, whereas static dissolution had a milder effect. Additionally, dynamic dissolution notably increased sandstone's hygroscopicity, with moisture absorption rising over time. This study highlights the distinct effects of dynamic and static dissolution on sandstone deterioration, offering insights for the preventive conservation of ancient stone structures. Tailored preservation strategies are essential for addressing these varying degradation mechanisms.
Keyword :
differential dissolution differential dissolution distribution of mechanical strength distribution of mechanical strength hygroscopic properties hygroscopic properties pore structure pore structure
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GB/T 7714 | Lyu, Quansheng , Liu, Chengyu , Hu, Dong et al. Comparative Study on the Deterioration of Surface Physical and Mechanical Properties of Sandstone Cultural Heritage Under Different Dissolution Conditions [J]. | APPLIED SCIENCES-BASEL , 2025 , 15 (8) . |
MLA | Lyu, Quansheng et al. "Comparative Study on the Deterioration of Surface Physical and Mechanical Properties of Sandstone Cultural Heritage Under Different Dissolution Conditions" . | APPLIED SCIENCES-BASEL 15 . 8 (2025) . |
APA | Lyu, Quansheng , Liu, Chengyu , Hu, Dong , Wu, Changyu . Comparative Study on the Deterioration of Surface Physical and Mechanical Properties of Sandstone Cultural Heritage Under Different Dissolution Conditions . | APPLIED SCIENCES-BASEL , 2025 , 15 (8) . |
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In South China, due to climatic factors, highly weathered granite is distributed across a large area and easily disintegrates after encountering water, causing many geological disasters and other problems. To determine the disintegration mechanism of highly weathered granite in South China, disintegration tests were carried out on highly weathered granite in the Fuzhou area under different immersion durations, cycle times, and flow rates, with the help of a self-designed disintegration test device. Moreover, the disintegration mechanism of the highly weathered granite was revealed using nuclear magnetic resonance (NMR) technology. The results demonstrated an increase in the cumulative relative disintegration with prolonged immersion time and the number of dry-wet cycles. Beyond a certain flow rate, the cumulative relative disintegration amount stabilized. There was a strong correlation between the steady disintegration rate and immersion time (or dry-wet cycles). The disintegration process of the highly weathered granite was divided into three stages: rapid, moderate, and stable disintegration. Notably, disintegration primarily occurred around the large pores. This study revealed that the variation in the immersion time (or wet-dry-scouring cycles) was fundamentally linked to changes in the relative volume of the large pores in the rock samples. These findings provide valuable insights for predicting and mitigating surface disasters on highly weathered granite slopes.
Keyword :
disintegration disintegration disintegration steady flow rate disintegration steady flow rate dry-wet cycles dry-wet cycles highly weathered granite highly weathered granite immersion time immersion time
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GB/T 7714 | He, Xiyang , Liu, Chengyu , Zhang, Xiangxiang et al. Disintegration Characteristics of Highly Weathered Granite under the Influence of Scouring [J]. | WATER , 2024 , 16 (3) . |
MLA | He, Xiyang et al. "Disintegration Characteristics of Highly Weathered Granite under the Influence of Scouring" . | WATER 16 . 3 (2024) . |
APA | He, Xiyang , Liu, Chengyu , Zhang, Xiangxiang , Wu, Changyu , Weng, Zhiyu . Disintegration Characteristics of Highly Weathered Granite under the Influence of Scouring . | WATER , 2024 , 16 (3) . |
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In this paper, uniaxial compression tests were carried out on nine concrete specimens with different coarse aggregate particle size ranges in single and continuous gradation at curing ages of 3, 7 and 28 d, respectively. The acoustic emission (AE) and microseismic (MS) signals of the whole loading process were monitored by combining AE and MS to investigate. The AE and MS signals characteristics of concrete with different coarse aggregate gradations during load damage at different curing ages were analyzedand the effect of the maximum coarse aggregate size on the damage evolution of concrete were investigated. Based on findings from experiments, as the maximum particle size of the coarse aggregate increases, the initial defects within the concrete specimens initially decrease and then increase. A larger size and the more heterogeneous of the coarse aggregate has an accelerating effect on the emergence and expansion of cracks throughout the load-induced damage process in concrete structures. In addition, when the curing age is brief, the expansion of internal cracks in concrete predominantly depends on the curing age, with the relationship to the maximum particle size of coarse aggregate being less evident. © The Author(s), under exclusive licence to Shiraz University 2024.
Keyword :
Acoustic emission Acoustic emission Coarse aggregate gradation Coarse aggregate gradation Curing age Curing age Microseismic Microseismic
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GB/T 7714 | Wu, C. , Zheng, Y. , Liu, C. . Effect of Coarse Aggregate Gradation on the Acoustic Emission and Microseismic Behavior of Concrete Under Load [J]. | Iranian Journal of Science and Technology - Transactions of Civil Engineering , 2024 . |
MLA | Wu, C. et al. "Effect of Coarse Aggregate Gradation on the Acoustic Emission and Microseismic Behavior of Concrete Under Load" . | Iranian Journal of Science and Technology - Transactions of Civil Engineering (2024) . |
APA | Wu, C. , Zheng, Y. , Liu, C. . Effect of Coarse Aggregate Gradation on the Acoustic Emission and Microseismic Behavior of Concrete Under Load . | Iranian Journal of Science and Technology - Transactions of Civil Engineering , 2024 . |
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The slit-cut method for the rockburst prevention and control is believed effective with its easiness in operation, adjustment and compatibility. However, there is limited advance knowledge of the physics of the slit-cut method, which is vital for the engineering designs. In this study, the biaxial compression tests with a synchronous AE (acoustic emission)-DIC (digital image correlation) monitoring are creatively carried out on the slit-contained circular opening specimens with different slit configurations to demonstrate the academic thoughts and mechanisms of the slit-cut method. The experiments document the two typical failure types namely the internal crack propagation and the dynamic rockburst, which occupy different AE hit rate characteristics and different entropy properties. With the occurrence of rockburst, the AE hit rate presents a bouncing ascend-descend trend, and a higher disorder and chaos is faithfully exhibited. Depending on the slit parameters, the slit-cut method can efficiently mitigate rockburst in terms of the occurrence frequency and magnitude. The underlying mechanism lies in the enhancement of the shear mechanism and the development of the internal cracks through which the stored energy can be greatly dissipated. However, due to the unrestricted shear failure in the slit-contained opening specimens, the opening-scale inward instability can be triggered by the internal crack coalescence, thus posing a threat to the safety of the opening. Implementing the slit-cut method with a consideration of the insitu stress conditions is evidently essential for the safe excavation.
Keyword :
Biaxial compression tests Biaxial compression tests Crack propagation Crack propagation Hard rock excavation Hard rock excavation Rockburst Rockburst Slit-cut method Slit-cut method
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GB/T 7714 | Zhang, Jian-Zhi , Zhou, Yi-Jie , Liu, Cheng-Yu et al. Experimental investigations on the failure characteristics of the slit-contained circular opening under biaxial compression: Insights into the rockburst prevention [J]. | THEORETICAL AND APPLIED FRACTURE MECHANICS , 2024 , 134 . |
MLA | Zhang, Jian-Zhi et al. "Experimental investigations on the failure characteristics of the slit-contained circular opening under biaxial compression: Insights into the rockburst prevention" . | THEORETICAL AND APPLIED FRACTURE MECHANICS 134 (2024) . |
APA | Zhang, Jian-Zhi , Zhou, Yi-Jie , Liu, Cheng-Yu , Yu, Jin , Li, Xing-Shang , Zhang, Ting . Experimental investigations on the failure characteristics of the slit-contained circular opening under biaxial compression: Insights into the rockburst prevention . | THEORETICAL AND APPLIED FRACTURE MECHANICS , 2024 , 134 . |
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Subsurface settlement is often triggered by soil erosion above underground defective pipelines. However, there is currently insufficient research on calculation methods for estimating ground settlement caused by defective pipeline. In this work, a series of laboratory experiments were conducted to investigate the impacts of the soil particle size, hydraulic gradient, thick-span ratio, and full pipe flow velocity on ground settlement around submerged defective pipelines. A sensitivity analysis was performed to further examine these factors. The experimental results revealed that there are three settlement modes, primarily determined by soil skeleton particle size and the thick-span ratio. . The full pipe flow velocity and hydraulic gradient significantly affected the settlement range, with the settlement range increasing as either the flow velocity or hydraulic gradient increased. Additionally, a new calculation model based on Manning's equation was developed to predict soil settlement. The error between the calculation and experiment results was less than 15%, demonstrating the accuracy and effectiveness of the proposed method.
Keyword :
Defective pipeline Defective pipeline Full pipe flow velocity Full pipe flow velocity Ground settlement Ground settlement Soil arch Soil arch Theoretical model Theoretical model
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GB/T 7714 | Chen, Bowen , Liu, Chengyu , Li, Qi et al. Experimental and theoretical investigations of ground settlement around submerged defective pipelines [J]. | TRANSPORTATION GEOTECHNICS , 2024 , 49 . |
MLA | Chen, Bowen et al. "Experimental and theoretical investigations of ground settlement around submerged defective pipelines" . | TRANSPORTATION GEOTECHNICS 49 (2024) . |
APA | Chen, Bowen , Liu, Chengyu , Li, Qi , Onyekwena, Chikezie Chimere . Experimental and theoretical investigations of ground settlement around submerged defective pipelines . | TRANSPORTATION GEOTECHNICS , 2024 , 49 . |
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To study the effect of freeze-thaw temperature change rate on the crack propagation characteristics and failure precursor in freeze-thawed sandstone, uniaxial compression tests were simultaneous monitoring for acoustic emission (AE) and microseismic (MS) signals. The results demonstrate that increased temperature change rates resulted in accelerated crack propagation, earlier rock failure, and lower brittleness; the failure mode changes from tensile to shear-tensile mixing; the proportion of tensile cracks decreases from 90.9% to 70.8%; and shear cracks increase from 9.1% to 29.2%. A comparative analysis of AE and MS provided insights into the evolution of crack propagation at multiple scales, enabling the classification of crack types and their relationship with propagation scale. Based on the precursor characteristic of the original waveform and time-domain curve in AE and MS signals, the advantageous areas of early-warming indicators for rock failure were identified. Compared with traditional indicators, the precursory indicators calculated using MS b-values and AE energy rates can obtain a larger early warning window, with maximum windows of 20.52%-29.29% and 7.09%-13.73% in high initial damage rocks and low initial damage rocks, respectively. Examined temperature change rate effects on mechanics and failure modes. Investigate multi-scale crack propagation evolution during loading using AE and MS. Crack type was classified and identified through normalization and KDE methods. The advantages field of early warning indicators for rock failure were evaluated.
Keyword :
acoustic emission acoustic emission crack classification crack classification failure precursor failure precursor freeze-thaw temperature change rate freeze-thaw temperature change rate microseismic microseismic multiple-scale crack multiple-scale crack
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GB/T 7714 | Zheng, Daozhe , Liu, Chengyu , Zhou, Annan et al. Multiple-scale crack propagation characteristics and failure precursor identification of freeze-thawed sandstone during loading [J]. | FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES , 2024 , 47 (8) : 2934-2954 . |
MLA | Zheng, Daozhe et al. "Multiple-scale crack propagation characteristics and failure precursor identification of freeze-thawed sandstone during loading" . | FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES 47 . 8 (2024) : 2934-2954 . |
APA | Zheng, Daozhe , Liu, Chengyu , Zhou, Annan , Zhang, Xiangxiang , Chen, Chenghai , Huang, Shengfeng . Multiple-scale crack propagation characteristics and failure precursor identification of freeze-thawed sandstone during loading . | FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES , 2024 , 47 (8) , 2934-2954 . |
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