{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,29]],"date-time":"2026-08-29T09:06:46Z","timestamp":1787994406130,"version":"build-2784847793"},"reference-count":40,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,3,17]],"date-time":"2025-03-17T00:00:00Z","timestamp":1742169600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["52369026"],"award-info":[{"award-number":["52369026"]}]},{"name":"National Natural Science Foundation of China","award":["52069029"],"award-info":[{"award-number":["52069029"]}]},{"name":"National Natural Science Foundation of China","award":["202302AN360003"],"award-info":[{"award-number":["202302AN360003"]}]},{"name":"National Natural Science Foundation of China","award":["202401BD070001-071"],"award-info":[{"award-number":["202401BD070001-071"]}]},{"name":"Yunnan Key Laboratory of Water Conservancy and Hydropower Engineering Safety","award":["52369026"],"award-info":[{"award-number":["52369026"]}]},{"name":"Yunnan Key Laboratory of Water Conservancy and Hydropower Engineering Safety","award":["52069029"],"award-info":[{"award-number":["52069029"]}]},{"name":"Yunnan Key Laboratory of Water Conservancy and Hydropower Engineering Safety","award":["202302AN360003"],"award-info":[{"award-number":["202302AN360003"]}]},{"name":"Yunnan Key Laboratory of Water Conservancy and Hydropower Engineering Safety","award":["202401BD070001-071"],"award-info":[{"award-number":["202401BD070001-071"]}]},{"name":"Yunnan Agricultural Basic Research Joint Special Project\u2014General Project","award":["52369026"],"award-info":[{"award-number":["52369026"]}]},{"name":"Yunnan Agricultural Basic Research Joint Special Project\u2014General Project","award":["52069029"],"award-info":[{"award-number":["52069029"]}]},{"name":"Yunnan Agricultural Basic Research Joint Special Project\u2014General Project","award":["202302AN360003"],"award-info":[{"award-number":["202302AN360003"]}]},{"name":"Yunnan Agricultural Basic Research Joint Special Project\u2014General Project","award":["202401BD070001-071"],"award-info":[{"award-number":["202401BD070001-071"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>To investigate the mechanical response characteristics of damming rockfill materials under different confining pressure conditions, this study integrates laboratory triaxial compression tests and PFC2D numerical simulations to systematically analyze their deformation evolution and failure mechanisms from both macroscopic and microscopic perspectives. Laboratory triaxial test results demonstrate that as the confining pressure increases, the peak deviatoric stress rises significantly, with the shear strength of specimens increasing from 769.43 kPa to 2140.98 kPa. Under low confining pressure, rockfill exhibits pronounced dilative behavior, whereas at high confining pressure, it transitions to contractive behavior. Additionally, particle breakage intensifies with increasing confinement, with the breakage rate rising from 4.25% to 8.33%. This particle fragmentation alters the granular skeleton structure, thereby affecting the overall mechanical properties and leading to a reduction in shear strength. Numerical simulations further reveal the micromechanical mechanisms governing rockfill behavior. The simulation results show a shear strength increase from 572.39 kPa to 2059.26 kPa, exhibiting a trend consistent with experimental findings. The shear failure mode manifests as a characteristic \u201cX-shaped\u201d shear band distribution, while at high confining pressures, shear fracture propagation is effectively inhibited, enhancing the overall structural stability. Furthermore, increasing confining pressure promotes denser interparticle contacts, with contact numbers increasing from 16,140 to 18,932 and the maximum contact force rising from 12.19 kN to 59.83 kN. The quantity and frequency of both strong and weak force chains also increase significantly, further influencing the mechanical response of the material. These findings provide deeper insights into the mechanical behavior of rockfill materials under varying confining pressures and offer theoretical guidance and engineering references for dam stability assessment and construction optimization.<\/jats:p>","DOI":"10.3390\/ma18061316","type":"journal-article","created":{"date-parts":[[2025,3,17]],"date-time":"2025-03-17T06:36:23Z","timestamp":1742193383000},"page":"1316","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Study on the Mechanical and Mesoscopic Properties of Rockfill Under Various Confining Pressures"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7456-1949","authenticated-orcid":false,"given":"Bin","family":"Ou","sequence":"first","affiliation":[{"name":"College of Water Conservancy, Yunnan Agricultural University, Kunming 650201, China"},{"name":"Yunnan Key Laboratory of Water Conservancy and Hydropower Engineering Safety, Kunming 650051, China"},{"name":"National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-8094-1215","authenticated-orcid":false,"given":"Haoquan","family":"Chi","sequence":"additional","affiliation":[{"name":"College of Water Conservancy, Yunnan Agricultural University, Kunming 650201, China"},{"name":"National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zixuan","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Water Conservancy, Yunnan Agricultural University, Kunming 650201, China"},{"name":"National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haoyu","family":"Qiu","sequence":"additional","affiliation":[{"name":"College of Water Conservancy, Yunnan Agricultural University, Kunming 650201, China"},{"name":"National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiahao","family":"Li","sequence":"additional","affiliation":[{"name":"College of Water Conservancy, Yunnan Agricultural University, Kunming 650201, China"},{"name":"National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanming","family":"Feng","sequence":"additional","affiliation":[{"name":"Yunnan Key Laboratory of Water Conservancy and Hydropower Engineering Safety, Kunming 650051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuyan","family":"Fu","sequence":"additional","affiliation":[{"name":"College of Water Conservancy, Yunnan Agricultural University, Kunming 650201, China"},{"name":"Yunnan Key Laboratory of Water Conservancy and Hydropower Engineering Safety, Kunming 650051, China"},{"name":"National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1007\/s11709-021-0693-0","article-title":"Experimental Study on Compaction-Induced Anisotropic Mechanical Property of Rockfill Material","volume":"15","author":"Zhang","year":"2021","journal-title":"Front. Struct. Civ. Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1007\/s40948-024-00883-6","article-title":"Investigation of the Particle Crushing Characteristics of Stacked Stone Materials under Different Stress Path Conditions","volume":"10","author":"Zhou","year":"2024","journal-title":"Geomech. Geophys. Geo-Energy Geo-Resour."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"5561427","DOI":"10.1155\/2021\/5561427","article-title":"Investigation of Lade-Kim Plastic Potential Applicability under Various Stress Paths for Rockfill Materials","volume":"2021","author":"Chen","year":"2021","journal-title":"Adv. Mater. Sci. Eng."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"120568","DOI":"10.1016\/j.powtec.2024.120568","article-title":"DEM Analysis of Wetting Deformation Characteristics of Rockfill Material Considering the Influence of Different Compaction Levels","volume":"452","author":"Chen","year":"2025","journal-title":"Powder Technol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Ning, F., Liu, J., Zou, D., Kong, X., and Cui, G. (2024). Super-Large-Scale Triaxial Tests to Study the Effects of Particle Size on the Monotonic Stress\u2013Strain Response of Rockfill Materials. Acta Geotech., 1\u201312.","DOI":"10.1007\/s11440-024-02471-0"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"506","DOI":"10.1007\/s10064-024-03944-y","article-title":"Particle Breakage, Deformation and Shear Strength of Conglomerate Rockfill Material: A Case Study of Masjed Soleyman Dam Cracking and Settlement","volume":"83","author":"Sadeghian","year":"2024","journal-title":"Bull. Eng. Geol. Environ."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Yang, Q., Zhang, J., Dai, X., Ye, Z., Wang, C., and Lu, S. (2024). Research on Permeability Characteristics and Gradation of Rockfill Material Based on Machine Learning. Water, 16.","DOI":"10.3390\/w16081135"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"101229","DOI":"10.1016\/j.trgeo.2024.101229","article-title":"Supervised Intelligent Prediction of Shear Strength of Rockfill Materials Based on Data Driven and a Case Study","volume":"45","author":"Li","year":"2024","journal-title":"Transp. Geotech."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Du, H., Zhang, S., Ma, W., Mu, Y., Cheng, T., and Zhang, Y. (2023). Experimental Study on the Characteristics of the Failure Strain Energy Density of Undisturbed Ice-Rich Frozen Clay. Atmosphere, 14.","DOI":"10.3390\/atmos14020203"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"110781","DOI":"10.1016\/j.engfracmech.2024.110781","article-title":"Fracture Mode of Water-Immersed Sandstone Based on Micro CT and Statistical Damage Model under Triaxial Compression","volume":"315","author":"Wang","year":"2025","journal-title":"Eng. Fract. Mech."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"04020012","DOI":"10.1061\/(ASCE)GM.1943-5622.0001601","article-title":"Particle Breakage and Deformation Behavior of Carbonate Sand under Drained and Undrained Triaxial Compression","volume":"20","author":"Wang","year":"2020","journal-title":"Int. J. Geomech."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Hu, F., Li, Z., Tian, Y., and Hu, R. (2021). Failure Patterns and Morphological Soil\u2013Rock Interface Characteristics of Frozen Soil\u2013Rock Mixtures under Compression and Tension. Appl. Sci., 11.","DOI":"10.3390\/app11010461"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"893","DOI":"10.1080\/19648189.2018.1552898","article-title":"Mathematical Model Revealing the Evolution of Particle Breakage and Particle-Size Distribution for Rockfill during Triaxial Shearing","volume":"25","author":"Guo","year":"2021","journal-title":"Eur. J. Environ. Civ. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"04023223","DOI":"10.1061\/IJGNAI.GMENG-8776","article-title":"Particle Breakage Model for Granular Geomaterials Considering Stress Paths","volume":"23","author":"Luo","year":"2023","journal-title":"Int. J. Geomech."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"116998","DOI":"10.1016\/j.oceaneng.2024.116998","article-title":"Macroscopic Behaviour and Mesoscopic Mechanism of Shear Strength Characteristics of Pile-Soil Interface under Cyclic Loading","volume":"297","author":"Zhou","year":"2024","journal-title":"Ocean Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"120544","DOI":"10.1016\/j.powtec.2024.120544","article-title":"Effect of Particle Size and Loading Frequency on the Small-Strain Modulus of Rockfill Materials: A DEM Study","volume":"452","author":"Yan","year":"2025","journal-title":"Powder Technol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"120403","DOI":"10.1016\/j.powtec.2024.120403","article-title":"Microscopic Simulation on Triaxial Compression Creep of Rockfill Based on Subcritical Crack Propagation Theory","volume":"449","author":"Zhou","year":"2025","journal-title":"Powder Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"134420","DOI":"10.1016\/j.conbuildmat.2023.134420","article-title":"Study on Reinforcing Mechanism of Carbon Nanotubes on Tensile Behavior of Gangue Cemented Rockfill","volume":"411","author":"Yu","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Han, H., Li, J., Shi, J., and Yang, C. (2022). Influence of Scale Effect on Strength and Deformation Characteristics of Rockfill Materials. Materials, 15.","DOI":"10.3390\/ma15155467"},{"key":"ref_20","first-page":"937","article-title":"Characteristics of Particle Breakage and Constitutive Model of Coarse Granular Material Incorporating Gradation Evolution","volume":"71","author":"Zhao","year":"2021","journal-title":"G\u00e9otechnique"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"4617","DOI":"10.1007\/s00366-021-01500-w","article-title":"The 3D Reconstruction of a Digital Model for Irregular Gangue Blocks and Its Application in PFC Numerical Simulation","volume":"38","author":"Li","year":"2021","journal-title":"Eng. Comput."},{"key":"ref_22","first-page":"433","article-title":"Numerical Simulation of the Effect of Confining Pressure and Tunnel Depth on the Vertical Settlement Using Particle Flow Code (With Direct Tensile Strength Calibration in PFC Modeling)","volume":"25","author":"Haeri","year":"2020","journal-title":"Smart Struct. Syst."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1007\/s10706-022-02286-4","article-title":"Mechanical Behavior and Rock Breaking Mechanism of Shield Hob Based on Particle Flow Code (PFC) Method","volume":"41","author":"Yang","year":"2022","journal-title":"Geotech. Geol. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Han, H., Ma, Y., He, W., Yang, W., and Fu, X. (2021). Numerical Simulation of Rockfill Materials Based on Fractal Theory. Appl. Sci., 12.","DOI":"10.3390\/app12010289"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1799","DOI":"10.1007\/s11668-024-01965-z","article-title":"Crack Initiation and Propagation Mechanism of Flawed Rock Mass Based on Improved Maximum Distortion Energy Theory and PFC Numerical Simulation","volume":"24","author":"Jing","year":"2024","journal-title":"J. Fail. Anal. Prev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"104342","DOI":"10.1016\/j.coldregions.2024.104342","article-title":"Mesoscopic Shear Evolution Characteristics of Frozen Soil-Concrete Interface","volume":"229","author":"Wan","year":"2025","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1007\/s12665-022-10411-y","article-title":"Effect of Joint Microcharacteristics on Macroshear Behavior of Single-Bolted Rock Joints by the Numerical Modeling with PFC","volume":"81","author":"Chen","year":"2022","journal-title":"Environ. Earth Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"105310","DOI":"10.1016\/j.jappgeo.2024.105310","article-title":"Acoustic Emission Response Characteristics and Numerical Simulation of Soil Failure under Uniaxial Compression","volume":"222","author":"Li","year":"2024","journal-title":"J. Appl. Geophys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"104709","DOI":"10.1016\/j.compgeo.2022.104752","article-title":"Multiscale Analysis of Tunnel Surrounding Rock Disturbance: A PFC3D-FLAC3D Coupling Algorithm with the Overlapping Domain Method","volume":"147","author":"Bai","year":"2022","journal-title":"Comput. Geotech."},{"key":"ref_30","first-page":"1116","article-title":"Study on Mechanical Properties and Mesoscopic Simulation of Coarse-Grained Soil Subgrade","volume":"51","author":"He","year":"2020","journal-title":"J. Cent. South Univ. (Sci. Technol.)"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1080\/10298436.2018.1435879","article-title":"Macro-Meso Freeze-Thaw Damage Mechanism of Soil-Rock Mixtures with Different Rock Contents","volume":"21","author":"Xing","year":"2020","journal-title":"Int. J. Pavement Eng."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1007\/s11204-023-09897-w","article-title":"Microscopic Mechanism of Coarse-Grained Soil under Triaxial Test Based on PFC-FLAC Coupling Method","volume":"60","author":"Zhang","year":"2023","journal-title":"Soil. Mech. Found. Eng."},{"key":"ref_33","unstructured":"(2019). Standard for Geotechnical Testing Methods (Standard No. GB\/T 50123-2019)."},{"key":"ref_34","first-page":"1","article-title":"Research Progress on Scaling Methods and Effects for Coarse-Grained Soil","volume":"40","author":"Pan","year":"2023","journal-title":"J. Yangtze River Sci. Res. Inst."},{"key":"ref_35","unstructured":"(2019). Standard for Soil Test Methods (Standard No. GB\/T 50213-2019)."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1007\/s40571-024-00786-z","article-title":"Rock Joint Filling Breakage under Three Different Instant Loading Conditions: Physical Test and PFC Simulation","volume":"12","author":"Zhou","year":"2024","journal-title":"Comput. Part. Mech."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1007\/s43452-024-00872-2","article-title":"Mesoscopic Analysis of Creep Characteristics of Hard Tuff Considering Damage","volume":"24","author":"Song","year":"2024","journal-title":"Arch. Civ. Mech. Eng."},{"key":"ref_38","first-page":"487","article-title":"Correlation Study on Macro-Mesoscopic Parameters of Sandstone Particle Flow Parallel Bond Model","volume":"8","author":"Wu","year":"2023","journal-title":"J. Min. Sci. Technol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1007\/s10035-024-01428-0","article-title":"Particle Breakage of Ultra-High Dam Rockfills under Drained Shearing","volume":"26","author":"Jin","year":"2024","journal-title":"Granul. Matter"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"3363","DOI":"10.1080\/19648189.2022.2136248","article-title":"Numerical Study of Dynamic Fracture Behaviors of Rock Containing Double Pre-Existing Flaws under Different Confined Stress and Flaw Geometry","volume":"27","author":"Wei","year":"2023","journal-title":"Eur. J. Environ. Civ. Eng."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/6\/1316\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:54:49Z","timestamp":1760028889000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/6\/1316"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,17]]},"references-count":40,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2025,3]]}},"alternative-id":["ma18061316"],"URL":"https:\/\/doi.org\/10.3390\/ma18061316","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,17]]}}}