{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T18:05:02Z","timestamp":1780682702373,"version":"3.54.1"},"reference-count":72,"publisher":"Public Library of Science (PLoS)","issue":"6","license":[{"start":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T00:00:00Z","timestamp":1780617600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["52274005"],"award-info":[{"award-number":["52274005"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>As oil and gas exploration and development continue to advance, ultra-deep and extra-deep formations have become the primary battleground for increasing global oil and gas reserves and production. The influence of high formation pressure on the macro-mechanical response of rock, particularly the mechanical response of indentations, remains unclear. This paper takes high-porosity rocks, which are commonly found in ultra-deep and extra-deep formations, as the research object. True triaxial compression test(TTCT) and conventional triaxial compression tests(CTCT) were conducted on high-porosity red sandstone to analyze brittle-ductile transition characteristics. A high confining pressure indentation test apparatus was developed to investigate the mechanical response of spherical indentation under high confining pressure. Numerical simulations were employed to analyze the underlying mechanism of this mechanical response. The results indicate that as the confining pressure increases, the sample undergoes three failure modes: shear failure, dilatant failure, and compactive cataclastic flow. The peak points of the stress\u2012strain curves present two distinct failure surfaces on the p-q meridian plane, and the location of these failure surfaces on the p-q meridian plane largely determines the stiffness response of the indentation. The indentation stiffness does not always increase with the increase of confining pressure, but rather exhibits a significant reduction near the brittle-ductile transition point. The release of residual stress leads to significant side crack propagation during indenter unloading, but this phenomenon is significantly inhibited under confining pressure. This paper offers preliminary insights into the mechanical behavior of oil and gas drilling scenarios under high confining pressures, such as those in ultra-deep and extra-deep formations, and provides an initial understanding of the indentation mechanical response of high-porosity rocks under high confining pressure.<\/jats:p>","DOI":"10.1371\/journal.pone.0347234","type":"journal-article","created":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T17:40:36Z","timestamp":1780681236000},"page":"e0347234","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Mechanical response of high-porosity rocks under high triaxial confining pressure and experimental study of indentation tests"],"prefix":"10.1371","volume":"21","author":[{"given":"Jingming","family":"Gai","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4955-5341","authenticated-orcid":true,"given":"Wei","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,6,5]]},"reference":[{"issue":"2","key":"pone.0347234.ref001","first-page":"12","article-title":"Inspiration and practice of drilling and completion in 10 000-meter ultra-deep wells in the Gulf of Mexico","volume":"52","author":"W Haige","year":"2024","journal-title":"Petroleum Drilling Techniques"},{"key":"pone.0347234.ref002","doi-asserted-by":"crossref","unstructured":"Mokaimi BSA, Alsarhan M, Mutairi AA, Al-Habib H, Anton J, Al-Khaldy M, et al. Managed Pressure Drilling Technique Commingled High Pore Pressure Section with Depleted Section, Eliminate Drilling Hazard and Pore Pressure Uncertainty Related High-Pressure High-Temperature in West Kuwait Jurassic Deep Wells. ADIPEC2024. p. D031S85R04.","DOI":"10.2118\/222742-MS"},{"issue":"4","key":"pone.0347234.ref003","first-page":"466","article-title":"Geological characteristics, formation conditions and accumulation model of deep and ultra-deep, high-porosity and high-permeability clastic reservoirs: a case study of Gulf of Mexico Basin","volume":"42","author":"X Zhang","year":"2021","journal-title":"Shiyou Xuebao\/Acta Petrolei Sinica"},{"issue":"5","key":"pone.0347234.ref004","first-page":"527","article-title":"Status and research suggestions on the drilling and completion technologies for onshore deep and ultra deep wells in China","volume":"42","author":"S Yinao","year":"2020","journal-title":"Oil Drilling & Production Technology"},{"key":"pone.0347234.ref005","doi-asserted-by":"crossref","first-page":"105619","DOI":"10.1016\/j.enggeo.2020.105619","article-title":"Rock strengthening or weakening upon heating in the mild temperature range?","volume":"272","author":"LNY Wong","year":"2020","journal-title":"Engineering Geology"},{"key":"pone.0347234.ref006","doi-asserted-by":"crossref","unstructured":"Alturkey K, Hunaidi F, Alarfaj M, Alharbi M. Review of Temperature Stabilization for Logging Operations in High-Pressure High-Temperature Wells. Middle East Oil, Gas and Geosciences Show (MEOS GEO)2025.","DOI":"10.2118\/227636-MS"},{"key":"pone.0347234.ref007","doi-asserted-by":"crossref","first-page":"112150","DOI":"10.1016\/j.engfracmech.2026.112150","article-title":"Coupled thermo-hydro-mechanical modeling of hydraulic fracture propagation in hot dry rock","volume":"340","author":"K Meng","year":"2026","journal-title":"Eng Fract Mech"},{"issue":"1","key":"pone.0347234.ref008","doi-asserted-by":"crossref","first-page":"1186","DOI":"10.1038\/s41598-023-28513-3","article-title":"Brittle-ductile transition stress of different rock types and its relationship with uniaxial compressive strength and Hoek-Brown material constant (mi)","volume":"13","author":"SM Davarpanah","year":"2023","journal-title":"Sci Rep"},{"issue":"12","key":"pone.0347234.ref009","doi-asserted-by":"crossref","first-page":"5993","DOI":"10.1007\/s00603-021-02595-9","article-title":"A New Perspective on the Brittle\u2013Ductile Transition of Rocks","volume":"54","author":"G Walton","year":"2021","journal-title":"Rock Mech Rock Eng"},{"issue":"3","key":"pone.0347234.ref010","first-page":"701","article-title":"Mechanical behavior of brittle-ductile transition in rocks at different depths","volume":"46","author":"H Xie","year":"2021","journal-title":"Meitan Xuebao\/Journal of the China Coal Society"},{"key":"pone.0347234.ref011","doi-asserted-by":"crossref","first-page":"19289","DOI":"10.1029\/2000JB900133","article-title":"Dilatancy, compaction, and failure mode in Solnhofen limestone","volume":"105","author":"P Baud","year":"2000","journal-title":"J Geophys Res"},{"key":"pone.0347234.ref012","article-title":"Shear\u2010enhanced compaction and strain localization: Inelastic deformation and constitutive modeling of four porous sandstones","volume":"111","author":"P Baud","year":"2006","journal-title":"J Geophys Res"},{"key":"pone.0347234.ref013","doi-asserted-by":"crossref","first-page":"21529","DOI":"10.1029\/2000JB900185","article-title":"Conditions for compaction bands in porous rock","volume":"105","author":"KA Issen","year":"2000","journal-title":"J Geophys Res"},{"issue":"1","key":"pone.0347234.ref014","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.mechmat.2004.01.004","article-title":"Numerical simulation of compaction bands in high-porosity sedimentary rock","volume":"37","author":"R Katsman","year":"2005","journal-title":"Mech Mater"},{"key":"pone.0347234.ref015","first-page":"2593","article-title":"Field evidence and experimental research on localized deformation bands in high-porosity rocks","volume":"27","author":"L Ting","year":"2008","journal-title":"Chin J Rock Mech Eng"},{"key":"pone.0347234.ref016","article-title":"Compaction, dilatancy, and failure in porous carbonate rocks","volume":"109","author":"V Vajdova","year":"2004","journal-title":"J Geophys Res"},{"key":"pone.0347234.ref017","article-title":"Micromechanics of cataclastic pore collapse in limestone","volume":"115","author":"W Zhu","year":"2010","journal-title":"J Geophys Res"},{"issue":"12","key":"pone.0347234.ref018","doi-asserted-by":"crossref","first-page":"1873","DOI":"10.1016\/j.jsg.2010.02.004","article-title":"Pure and shear-enhanced compaction bands in Aztec Sandstone","volume":"32","author":"P Eichhubl","year":"2010","journal-title":"Journal of Structural Geology"},{"issue":"10","key":"pone.0347234.ref019","doi-asserted-by":"crossref","first-page":"1477","DOI":"10.1016\/j.jsg.2011.08.001","article-title":"Conditions and implications for compaction band formation in the Navajo Sandstone, Utah","volume":"33","author":"H Fossen","year":"2011","journal-title":"Journal of Structural Geology"},{"issue":"2","key":"pone.0347234.ref020","doi-asserted-by":"crossref","DOI":"10.1029\/2024JB030022","article-title":"Development of Permeability Heterogeneity During Compaction of Porous Sandstone","volume":"130","author":"N Brantut","year":"2025","journal-title":"JGR Solid Earth"},{"issue":"6","key":"pone.0347234.ref021","doi-asserted-by":"crossref","first-page":"2351","DOI":"10.1016\/j.jrmge.2023.07.022","article-title":"A review of rock macro-indentation: Theories, experiments, simulations, and applications","volume":"16","author":"W Xie","year":"2024","journal-title":"Journal of Rock Mechanics and Geotechnical Engineering"},{"issue":"1410","key":"pone.0347234.ref022","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1038\/055006f0","article-title":"Hertz\u2019s Miscellaneous Papers","volume":"55","author":"G GFF","year":"1896","journal-title":"Nature"},{"issue":"8","key":"pone.0347234.ref023","doi-asserted-by":"crossref","first-page":"1977","DOI":"10.1111\/j.1151-2916.1998.tb02580.x","article-title":"Indentation of Ceramics with Spheres: A Century after Hertz","volume":"81","author":"BR Lawn","year":"1998","journal-title":"Journal of the American Ceramic Society"},{"issue":"1","key":"pone.0347234.ref024","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1557\/jmr.2004.19.1.3","article-title":"Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology","volume":"19","author":"WC Oliver","year":"2004","journal-title":"J Mater Res"},{"issue":"6","key":"pone.0347234.ref025","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1016\/S0148-9062(97)00334-3","article-title":"Indentation hardness testing of rock","volume":"35","author":"T Szwedzicki","year":"1998","journal-title":"International Journal of Rock Mechanics and Mining Sciences"},{"issue":"1","key":"pone.0347234.ref026","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.tust.2008.04.002","article-title":"Assessment of brittleness using rock strength and density with punch penetration test","volume":"24","author":"S Yagiz","year":"2009","journal-title":"Tunnelling and Underground Space Technology"},{"key":"pone.0347234.ref027","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/j.petrol.2018.03.024","article-title":"Development of a new rock drillability index for oil and gas reservoir rocks using punch penetration test","volume":"166","author":"M Anemangely","year":"2018","journal-title":"Journal of Petroleum Science and Engineering"},{"issue":"2","key":"pone.0347234.ref028","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1007\/BF01583958","article-title":"A force-indentation model for brittle rocks","volume":"22","author":"SS Pang","year":"1989","journal-title":"Rock Mech Rock Engng"},{"issue":"4","key":"pone.0347234.ref029","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1007\/s10064-008-0162-1","article-title":"Indentation hardness test to estimate the sawability of carbonate rocks","volume":"67","author":"S Kahraman","year":"2008","journal-title":"Bull Eng Geol Environ"},{"key":"pone.0347234.ref030","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.petrol.2013.11.027","article-title":"A new method for correlating rock strength to indentation tests","volume":"112","author":"M Haftani","year":"2013","journal-title":"Journal of Petroleum Science and Engineering"},{"key":"pone.0347234.ref031","doi-asserted-by":"crossref","first-page":"104647","DOI":"10.1016\/j.ijrmms.2021.104647","article-title":"Experimental investigation of rock strength using indentation test and point load test","volume":"139","author":"W-Q Xie","year":"2021","journal-title":"International Journal of Rock Mechanics and Mining Sciences"},{"issue":"12","key":"pone.0347234.ref032","article-title":"Experimental investigation and numerical analyses for red sandstone rock fragmentation","volume":"20","author":"J Zou","year":"2020","journal-title":"Int J Geomech"},{"issue":"3","key":"pone.0347234.ref033","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1016\/j.ijmst.2022.02.002","article-title":"Experimental investigation on hard rock fragmentation of inserted tooth cutter using a newly designed indentation testing apparatus","volume":"32","author":"J Zou","year":"2022","journal-title":"Int J Min Sci Technol"},{"key":"pone.0347234.ref034","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.ijrmms.2019.04.018","article-title":"Rock cone penetration test under lateral confining pressure","volume":"119","author":"K Fang","year":"2019","journal-title":"International Journal of Rock Mechanics and Mining Sciences"},{"key":"pone.0347234.ref035","doi-asserted-by":"crossref","first-page":"104063","DOI":"10.1016\/j.ijrmms.2019.104063","article-title":"Experimental investigation of rock breakage by a conical pick and its application to non-explosive mechanized mining in deep hard rock","volume":"122","author":"S Wang","year":"2019","journal-title":"International Journal of Rock Mechanics and Mining Sciences"},{"issue":"1","key":"pone.0347234.ref036","doi-asserted-by":"crossref","DOI":"10.1007\/s40948-022-00345-x","article-title":"Experimental investigation and theoretical analysis of indentations on cuboid hard rock using a conical pick under uniaxial lateral stress","volume":"8","author":"S Wang","year":"2022","journal-title":"Geomech Geophys Geo-energ Geo-resour"},{"issue":"6","key":"pone.0347234.ref037","doi-asserted-by":"crossref","first-page":"1766","DOI":"10.1016\/S1003-6326(21)65615-7","article-title":"Analyses and predictions of rock cuttabilities under different confining stresses and rock properties based on rock indentation tests by conical pick","volume":"31","author":"S Wang","year":"2021","journal-title":"Transactions of Nonferrous Metals Society of China"},{"key":"pone.0347234.ref038","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1016\/j.ijrmms.2014.07.022","article-title":"Use of indentation tests to study the influence of confining stress on rock fragmentation by a TBM cutter","volume":"72","author":"LJ Yin","year":"2014","journal-title":"International Journal of Rock Mechanics and Mining Sciences"},{"issue":"9","key":"pone.0347234.ref039","doi-asserted-by":"crossref","first-page":"2786","DOI":"10.1007\/s11771-021-4766-y","article-title":"Influence of brittleness and confining stress on rock cuttability based on rock indentation tests","volume":"28","author":"S Wang","year":"2021","journal-title":"J Cent South Univ"},{"key":"pone.0347234.ref040","doi-asserted-by":"crossref","first-page":"603","DOI":"10.1007\/BF00876527","article-title":"Volume changes during fracture and frictional sliding: A review","volume":"116","author":"WF Brace","year":"1978","journal-title":"Pure Appl Geophys"},{"key":"pone.0347234.ref041","unstructured":"Moronkeji DA, Shouse R, Prasad U, Franquet JA. Size Effects on Triaxial Strength Measurements and Brittle-Ductile Behavior of Carbonate Rock. 50th US Rock Mechanics\/Geomechanics Symposium2016. p. ARMA-2016-371."},{"issue":"10","key":"pone.0347234.ref042","doi-asserted-by":"crossref","first-page":"2959","DOI":"10.1007\/s11771-020-4521-9","article-title":"In-site core disking phenomenon and break mechanism of hard marble: Investigation in 2400 m deep-buried underground laboratory","volume":"27","author":"S Zhong","year":"2020","journal-title":"J Cent South Univ"},{"key":"pone.0347234.ref043","doi-asserted-by":"crossref","first-page":"3027","DOI":"10.1029\/96JB03282","article-title":"The transition from brittle faulting to cataclastic flow: Permeability evolution","volume":"102","author":"W Zhu","year":"1997","journal-title":"J Geophys Res"},{"issue":"3","key":"pone.0347234.ref044","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1016\/j.jrmge.2018.08.001","article-title":"The Hoek\u2013Brown failure criterion and GSI \u2013 2018 edition","volume":"11","author":"E Hoek","year":"2019","journal-title":"J Rock Mech Geotech Eng"},{"key":"pone.0347234.ref045","unstructured":"Mogi K, editor Pressure Dependence of Rock Strength and Transition from Brittle Fracture to Ductile Flow1966."},{"key":"pone.0347234.ref046","doi-asserted-by":"crossref","first-page":"105894","DOI":"10.1016\/j.ijrmms.2024.105894","article-title":"Effect of artificially induced microcracks near the rock surface on granite fragmentation performance under heating treatment","volume":"182","author":"Y Li","year":"2024","journal-title":"International Journal of Rock Mechanics and Mining Sciences"},{"key":"pone.0347234.ref047","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.ijmecsci.2014.10.007","article-title":"Experimental studies of the resultant contact forces in drillbit\u2013rock interaction","volume":"91","author":"OK Ajibose","year":"2015","journal-title":"Int J Mech Sci"},{"issue":"6","key":"pone.0347234.ref048","doi-asserted-by":"crossref","first-page":"1539","DOI":"10.1007\/s10706-015-9920-6","article-title":"Microstructure effect on hard rock damage and fracture during indentation process","volume":"33","author":"S Souissi","year":"2015","journal-title":"Geotech Geol Eng"},{"issue":"2","key":"pone.0347234.ref049","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1007\/s006030050010","article-title":"Normal Wedge Indentation in Rocks with Lateral Confinement","volume":"31","author":"H Huang","year":"1998","journal-title":"Rock Mechanics and Rock Engineering"},{"key":"pone.0347234.ref050","doi-asserted-by":"crossref","DOI":"10.1016\/j.compgeo.2022.104693","article-title":"Cavity expansion analysis of normal indention of rocks with lateral confinement","volume":"145","author":"Y Cheng","year":"2022","journal-title":"Comput Geotech"},{"issue":"4","key":"pone.0347234.ref051","doi-asserted-by":"crossref","first-page":"2027","DOI":"10.1007\/s00603-021-02732-4","article-title":"Normal Indentation of Rock Specimens with a Blunt Tool: Role of Specimen Size and Indenter Geometry","volume":"55","author":"H Yang","year":"2022","journal-title":"Rock Mech Rock Eng"},{"issue":"2","key":"pone.0347234.ref052","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1017\/S1727719100002677","article-title":"Acoustic emission at wedge indentation fracture in quasi-brittle materials","volume":"25","author":"LH Chen","year":"2011","journal-title":"J Mech"},{"issue":"4","key":"pone.0347234.ref053","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1007\/s006030070003","article-title":"An Analytical Model for the Indentation of Rocks by Blunt Tools","volume":"33","author":"H Alehossein","year":"2000","journal-title":"Rock Mechanics and Rock Engineering"},{"key":"pone.0347234.ref054","doi-asserted-by":"crossref","first-page":"104899","DOI":"10.1016\/j.ijrmms.2021.104899","article-title":"Development and application of an in-situ indentation testing system for the prediction of tunnel boring machine performance","volume":"147","author":"X-P Zhang","year":"2021","journal-title":"International Journal of Rock Mechanics and Mining Sciences"},{"key":"pone.0347234.ref055","doi-asserted-by":"crossref","DOI":"10.1017\/CBO9781139171731","volume-title":"Contact Mechanics","author":"KL Johnson","year":"1985"},{"key":"pone.0347234.ref056","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/j.ijrmms.2016.05.012","article-title":"Experimental and numerical study of Kuru granite under confined compression and indentation","volume":"87","author":"D Tkalich","year":"2016","journal-title":"International Journal of Rock Mechanics and Mining Sciences"},{"issue":"13","key":"pone.0347234.ref057","doi-asserted-by":"crossref","first-page":"1483","DOI":"10.1002\/nag.974","article-title":"Numerical modelling of bit\u2013rock fracture mechanisms in percussive drilling with a continuum approach","volume":"35","author":"T Saksala","year":"2010","journal-title":"Num Anal Meth Geomechanics"},{"key":"pone.0347234.ref058","doi-asserted-by":"crossref","first-page":"94","DOI":"10.1016\/j.powtec.2015.04.023","article-title":"Physical interpretations for cap parameters of the modified Drucker-Prager cap model in relation to the deviator stress curve of a particulate compact in conventional triaxial testing","volume":"280","author":"H Shin","year":"2015","journal-title":"Powder Technology"},{"issue":"10","key":"pone.0347234.ref059","doi-asserted-by":"crossref","first-page":"3627","DOI":"10.1007\/s00603-019-01783-y","article-title":"Coupled Modeling of Sedimentary Basin and Geomechanics: A Modified Drucker\u2013Prager Cap Model to Describe Rock Compaction in Tectonic Context","volume":"52","author":"N Guy","year":"2019","journal-title":"Rock Mech Rock Eng"},{"key":"pone.0347234.ref060","unstructured":"Corp DSS. ABAQUS Theory Manual 6.13. 2013."},{"key":"pone.0347234.ref061","author":"C Lu","year":"2009"},{"issue":"2","key":"pone.0347234.ref062","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/0167-6636(95)00002-X","article-title":"Experimental determination of probability distributions for parameters of a salem limestone cap plasticity model","volume":"21","author":"AF Fossum","year":"1995","journal-title":"Mech Mater"},{"issue":"2","key":"pone.0347234.ref063","doi-asserted-by":"crossref","first-page":"238","DOI":"10.1115\/1.482793","article-title":"Densification behavior of ceramic powder under cold compaction","volume":"122","author":"KT Kim","year":"1998","journal-title":"J Eng Mater Technol"},{"issue":"12","key":"pone.0347234.ref064","doi-asserted-by":"crossref","first-page":"2911","DOI":"10.1023\/A:1017902503839","article-title":"Mechanical properties and shear failure surfaces for two alumina powders in triaxial compression","volume":"36","author":"DH Zeuch","year":"2001","journal-title":"J Mater Sci"},{"issue":"12","key":"pone.0347234.ref065","doi-asserted-by":"crossref","first-page":"2523","DOI":"10.1016\/S0020-7403(02)00189-3","article-title":"Near net shape processing of a sintered alumina component: adjustment of pressing parameters through finite element simulation","volume":"44","author":"H Kim","year":"2002","journal-title":"Int J Mech Sci"},{"issue":"3","key":"pone.0347234.ref066","doi-asserted-by":"crossref","first-page":"928","DOI":"10.1016\/j.apt.2015.03.008","article-title":"Determination of the constants of cap model for compaction of three metal powders","volume":"26","author":"GH Majzoobi","year":"2015","journal-title":"Advanced Powder Technology"},{"issue":"1","key":"pone.0347234.ref067","doi-asserted-by":"crossref","first-page":"104302","DOI":"10.1016\/j.apt.2023.104302","article-title":"Novel method for the accurate calculation of Drucker\u2013Prager cap model parameters and reduction of experimental time and effort","volume":"35","author":"T Sato","year":"2024","journal-title":"Advanced Powder Technology"},{"key":"pone.0347234.ref068","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.commatsci.2014.10.024","article-title":"A simulation-based determination of cap parameters of the modified Drucker\u2013Prager cap model by considering specimen barreling during conventional triaxial testing","volume":"100","author":"H Shin","year":"2015","journal-title":"Comput Mater Sci"},{"key":"pone.0347234.ref069","doi-asserted-by":"crossref","unstructured":"Green S, Judzis A, Curry D, Black A, Prasad U, Rogers J. Single Cutter Impact Tests Investigate Deep-Well Hammer-Drilling Performance. SPE Annual Technical Conference and Exhibition2005. p. SPE-97173-MS.","DOI":"10.2118\/97173-MS"},{"issue":"2","key":"pone.0347234.ref070","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1007\/BF00047063","article-title":"Determination of fracture energy, process zone longth and brittleness number from size effect, with application to rock and conerete","volume":"44","author":"KMT Ba","year":"1990","journal-title":"Int J Fract"},{"issue":"14","key":"pone.0347234.ref071","doi-asserted-by":"crossref","first-page":"4741","DOI":"10.1029\/JB073i014p04741","article-title":"Brittle-ductile transition in rocks","volume":"73","author":"JD Byerlee","year":"1968","journal-title":"J Geophys Res"},{"key":"pone.0347234.ref072","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1007\/BF00876528","article-title":"Friction of rocks","volume":"116","author":"J Byerlee","year":"1978","journal-title":"PAGEOPH"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0347234","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T17:40:50Z","timestamp":1780681250000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0347234"}},"subtitle":[],"editor":[{"given":"Guojin","family":"Qin","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,6,5]]},"references-count":72,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,6,5]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0347234","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,5]]}}}