{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T18:27:06Z","timestamp":1762453626811,"version":"build-2065373602"},"reference-count":31,"publisher":"Public Library of Science (PLoS)","issue":"11","license":[{"start":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T00:00:00Z","timestamp":1762387200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100013076","name":"National Major Science and Technology Projects of China","doi-asserted-by":"publisher","award":["2024ZD1700206"],"award-info":[{"award-number":["2024ZD1700206"]}],"id":[{"id":"10.13039\/501100013076","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Key Research and Development Special Project of Henan Province","award":["241111320800"],"award-info":[{"award-number":["241111320800"]}]},{"DOI":"10.13039\/501100018551","name":"Science and Technology Innovation Talents in Universities of Henan Province","doi-asserted-by":"publisher","award":["23HASTIT011"],"award-info":[{"award-number":["23HASTIT011"]}],"id":[{"id":"10.13039\/501100018551","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>\n                    To investigate the permeability enhancement effect of microorganisms (Methanogens) on anthracite and their impact on coal strength, static fracture tests were conducted on semi-circular SCB specimens with prefabricated cracks of varying angles after immersion in neutral and microbial solutions. The fracture process was monitored using digital image correlation DIC and VIC-2D techniques. The effects of different solutions and prefabricated angle cracks on the strength, deformation characteristics and fracture toughness of anthracite were analyzed. Simultaneously, the influence of the displacement field at the prefabricated crack tip of the coal sample during the failure process and the evolution characteristics of the strain field of the coal sample at different stages of the process were analyzed. The test results show that the composite specimens with different slit angles and different solution environments have significant differences in the loading process. The samples mainly experience tensile failure, with shear failure as a supplement. Fracture toughness decreased as the angle between the crack and loading direction diminished. In the microbial-solution environment, the ability of the samples to resist crack propagation is further reduced. Tensile deformation initiation occurred at 57.97\u2009~\u200986.7% P\n                    <jats:sub>max<\/jats:sub>\n                    for neutral solutions and 36.36\u2009~\u200960.52% P\n                    <jats:sub>max<\/jats:sub>\n                    for microbial solutions. Microbial solutions induced earlier crack tip tensile deformation, promoting tensile failure and extending the fracture process zone (FPZ) length.\n                  <\/jats:p>","DOI":"10.1371\/journal.pone.0333227","type":"journal-article","created":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T18:23:14Z","timestamp":1762453394000},"page":"e0333227","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Study on fracture of coal samples with different fracture angles under microbial environment"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4258-9592","authenticated-orcid":true,"given":"Wen","family":"Wang","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuxiang","family":"Song","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daping","family":"Xia","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaowei","family":"Lu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Songsong","family":"Guan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chuanjiu","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yiwen","family":"Ju","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2025,11,6]]},"reference":[{"key":"pone.0333227.ref001","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.coal.2018.02.013","article-title":"Potential application of developed methanogenic microbial consortia for coal biogasification","volume":"188","author":"J Fuertez","year":"2018","journal-title":"Int J Coal Geol"},{"key":"pone.0333227.ref002","doi-asserted-by":"crossref","first-page":"118935","DOI":"10.1016\/j.energy.2020.118935","article-title":"Feasibility study of enhanced biogenic coalbed methane production by super-critical CO2 extraction","volume":"214","author":"H Guo","year":"2021","journal-title":"Energy"},{"issue":"1","key":"pone.0333227.ref003","first-page":"335","article-title":"Experimental research on microbial increasing permeability of coal reservoir and its significance","volume":"7","author":"G Hongyu","year":"2013","journal-title":"J Pure Appl Microbiol"},{"issue":"09","key":"pone.0333227.ref004","first-page":"1886","article-title":"Analysis of microbial antireflection effect and mechanism of different rank coal","volume":"39","author":"u Guo H o n g y","year":"2014","journal-title":"Coal J"},{"issue":"1","key":"pone.0333227.ref005","doi-asserted-by":"crossref","first-page":"7","DOI":"10.3390\/en13010007","article-title":"Comprehensive Fractal Model and Pore Structural Features of Medium- and Low-Rank Coal from the Zhunnan Coalfield of Xinjiang, China","volume":"13","author":"H Lin","year":"2019","journal-title":"Energies"},{"issue":"01","key":"pone.0333227.ref006","first-page":"27","article-title":"Interaction between pore structure of different rank coals and biomethane from coal","volume":"46","author":"D Xia","year":"2023","journal-title":"Coal conversion"},{"key":"pone.0333227.ref007","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1016\/j.fuel.2015.10.011","article-title":"Micro-pores and fractures of coals analysed by field emission scanning electron microscopy and fractal theory","volume":"164","author":"J Pan","year":"2016","journal-title":"Fuel"},{"key":"pone.0333227.ref008","doi-asserted-by":"crossref","first-page":"104081","DOI":"10.1016\/j.coal.2022.104081","article-title":"Characterizing mechanical heterogeneity of coal at nano-to-micro scale using combined nanoindentation and FESEM-EDS","volume":"261","author":"A Liu","year":"2022","journal-title":"Int J Coal Geol"},{"issue":"05","key":"pone.0333227.ref009","first-page":"63","article-title":"Fine characterization of pore evolution during coal biodegradation based on micro-CT","volume":"47","author":"Z Dong","year":"2019","journal-title":"Coalfield geology and exploration"},{"key":"pone.0333227.ref010","doi-asserted-by":"crossref","first-page":"1051","DOI":"10.1515\/pac-2014-1117","article-title":"Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution","volume":"87","author":"M Thommes","year":"2015","journal-title":"Pure and Applied Chemistry"},{"issue":"6","key":"pone.0333227.ref011","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0247908","article-title":"Dynamic fracture mechanics and energy distribution rate response characteristics of coal containing bedding structure","volume":"16","author":"S Gong","year":"2021","journal-title":"PLoS One"},{"issue":"11","key":"pone.0333227.ref012","first-page":"90","article-title":"Variation of pore structure of bituminous coal under the action of Firmicutes","volume":"45","author":"i Zhao C h e n g c a","year":"2024","journal-title":"Safety"},{"key":"pone.0333227.ref013","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.ijsolstr.2020.03.004","article-title":"Mode I fracture growth in anisotropic rocks: Theory and experiment[J","volume":"195","author":"M Nejati","year":"2020","journal-title":"International J Solids and Structures"},{"key":"pone.0333227.ref014","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.engfracmech.2018.08.017","article-title":"On the link between fracture toughness, tensile strength, and fracture process zone in anisotropic rocks","volume":"201","author":"N Dutler","year":"2018","journal-title":"Eng Fracture Mechanics"},{"issue":"10","key":"pone.0333227.ref015","first-page":"2010","article-title":"Study on dynamic strength characteristics of saturated coal samples under true triaxial dynamic and static combined loading","volume":"38","author":"W Wang","year":"2019","journal-title":"Rock mechanics and engineering"},{"issue":"03","key":"pone.0333227.ref016","first-page":"611","article-title":"Mechanical characteristics and meso-mechanical analysis of water-bearing coal samples under dynamic and static combined loading","volume":"41","author":"W Wang","year":"2016","journal-title":"Journal of Coal"},{"key":"pone.0333227.ref017","first-page":"3965","article-title":"Analysis of energy dissipation characteristics of water-bearing coal samples under combined static and dynamic loading","volume":"34","author":"W Wang","year":"2015","journal-title":"J Rock Mechanics and Engineering"},{"issue":"9","key":"pone.0333227.ref018","doi-asserted-by":"crossref","first-page":"4965","DOI":"10.1007\/s00603-021-02541-9","article-title":"Influences of Loading Method and Notch Type on Rock Fracture Toughness Measurements: From the Perspectives of T-Stress and Fracture Process Zone","volume":"54","author":"M Wei","year":"2021","journal-title":"Rock Mech Rock Eng"},{"issue":"2","key":"pone.0333227.ref019","doi-asserted-by":"crossref","first-page":"177","DOI":"10.3390\/math10020177","article-title":"Study on Mechanical Characteristics and Failure Modes of Coal\u2013Mudstone Combined Body with Prefabricated Crack","volume":"10","author":"H Lv","year":"2022","journal-title":"Mathematics"},{"issue":"05","key":"pone.0333227.ref020","first-page":"1041","article-title":"Study on fracture characteristics of coal samples based on straight crack semicircle three-point bending test","volume":"39","author":"i Yang L e","year":"2022","journal-title":"J Mining and Safety Engineering"},{"key":"pone.0333227.ref021","doi-asserted-by":"crossref","first-page":"103014","DOI":"10.1016\/j.tafmec.2021.103014","article-title":"Estimation of the mode I fracture toughness and evaluations on the strain behaviors of the compacted mine tailings from full-field displacement fields via digital image correlation","volume":"114","author":"N Zhang","year":"2021","journal-title":"Theoretical Applied Fracture Mechanics"},{"key":"pone.0333227.ref022","doi-asserted-by":"crossref","first-page":"103377","DOI":"10.1016\/j.tafmec.2022.103377","article-title":"Comparative study on modes I and II fracture characteristics of bituminous coal using asymmetric semi-circular bend specimen","volume":"120","author":"Y Zhao","year":"2022","journal-title":"Theoretical and Applied Fracture Mechanics"},{"key":"pone.0333227.ref023","doi-asserted-by":"crossref","first-page":"108524","DOI":"10.1016\/j.petrol.2021.108524","article-title":"Influence of the fracture process zone on fracture propagation mode in layered rocks","volume":"202","author":"R Pan","year":"2021","journal-title":"Journal of Petroleum Science and Engineering"},{"issue":"03","key":"pone.0333227.ref024","first-page":"433","article-title":"Experimental study on the influence of bedding and pre-crack direction on the fracture mechanical properties of coal","volume":"41","author":"i Wang W e","year":"2022","journal-title":"Journal of Rock Mechanics and Engineering"},{"key":"pone.0333227.ref025","unstructured":"Su Xianbo, Xia Daping, Zhao Weizhong, Fu Haijiao, Guo Hongguang, He Huan, Bao Yuan, Li Dan, Wei Guoqin.Research progress of coalbed methane bioengineering[J].Coal science and technology, 2020,48 (06): 1\u201330."},{"issue":"08","key":"pone.0333227.ref026","first-page":"3399","article-title":"Experimental study on fracture toughness and fracture process zone anisotropy of anthracite","volume":"49","author":"S Gong","year":"2024","journal-title":"Journal of Coal"},{"issue":"07","key":"pone.0333227.ref027","first-page":"1097","article-title":"Effects of biomethane metabolism on coal pore structure","volume":"25","author":"D Xia","year":"2014","journal-title":"Natural Gas Geoscience"},{"key":"pone.0333227.ref028","doi-asserted-by":"crossref","first-page":"111135","DOI":"10.1016\/j.engfracmech.2025.111135","article-title":"Evaluation of low-temperature fracture and damage of asphalt concrete using SCB test combined with DIC","volume":"321","author":"S Zhu","year":"2025","journal-title":"Engineering Fracture Mechanics"},{"issue":"08","key":"pone.0333227.ref029","first-page":"25","article-title":"Study on the effect of fulcrum friction on the I-II mixed stress field of SCB specimen","volume":"43","author":"Y Li","year":"2024","journal-title":"J Chongqing Jiaotong University (Natural Science Edition)"},{"issue":"03","key":"pone.0333227.ref030","first-page":"528","article-title":"Effect of crack length and angle on fracture characteristics of red sandstone semi-circular specimens","volume":"33","author":"K Zhou","year":"2025","journal-title":"Gold Science and Technol"},{"issue":"06","key":"pone.0333227.ref031","first-page":"154","article-title":"Study on tensile properties and fracture characteristics of NSCB brittle specimens based on DIC method","volume":"45","author":"i Liu L o n g f e","year":"2025","journal-title":"Mining Res development"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0333227","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T18:23:22Z","timestamp":1762453402000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0333227"}},"subtitle":[],"editor":[{"given":"Karen","family":"Alavi","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2025,11,6]]},"references-count":31,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2025,11,6]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0333227","relation":{},"ISSN":["1932-6203"],"issn-type":[{"type":"electronic","value":"1932-6203"}],"subject":[],"published":{"date-parts":[[2025,11,6]]}}}