{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,16]],"date-time":"2025-10-16T08:41:23Z","timestamp":1760604083500,"version":"build-2065373602"},"reference-count":35,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2025,10,16]],"date-time":"2025-10-16T00:00:00Z","timestamp":1760572800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Sciences"],"abstract":"<jats:p>The main goal of this study is to analyse and quantify errors, doubts, and uncertainties associated with the use of Q-Barton system parameters. This study also analyses how related factors influence the observer in tunnel openings. Data from six penstock tunnels of an underground hydraulic circuit at a hydroelectric power plant were used to study the application of the Q-Barton index. Records of values adopted at tunnel opening faces were compared with values calculated and quantified objectively. The values adopted by a geologist at the tunnel opening (Q-Barton-geologist) were compared with statistical values of the Q-Barton (Q-Barton-GGDB) generated from a factual database. This comparison enables the evaluation of the accuracy and influence of the Q-Barton system in tunnel openings, as well as the consequences on labour days and geotechnical support costs associated with a structure represented by the sample used. Using Q-Barton-GGDB, savings of 17.5% on geotechnical supports and 12.9% on labour days will be achieved. Final results highlight the need to explore the issues discussed here further.<\/jats:p>","DOI":"10.3390\/app152011075","type":"journal-article","created":{"date-parts":[[2025,10,16]],"date-time":"2025-10-16T07:29:38Z","timestamp":1760599778000},"page":"11075","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Reduction of Q-Barton Uncertainty: Proposal of a New Methodology Based on a Factual Geological\u2013Geotechnical Database to Apply in Tunnels"],"prefix":"10.3390","volume":"15","author":[{"given":"Benedito Calejo","family":"Rodrigues","sequence":"first","affiliation":[{"name":"CCT\u2014Earth Sciences Centre, University of Minho, 4710-057 Braga, Portugal"},{"name":"CONGEO, Consultores de Geologia, Lda., 4400-285 Vila Nova de Gaia, Portugal"}]},{"given":"Jo\u00e3o","family":"Sousa","sequence":"additional","affiliation":[{"name":"Independent Researcher, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6921-358X","authenticated-orcid":false,"given":"Jorge","family":"Pamplona","sequence":"additional","affiliation":[{"name":"CCT\u2014Earth Sciences Centre, University of Minho, 4710-057 Braga, Portugal"}]},{"given":"Ant\u00f3nio Campos e","family":"Matos","sequence":"additional","affiliation":[{"name":"FEUP\u2014Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal"},{"name":"GEG, Gabinete de Estruturas e Geotecnia, Lda., 4200-024 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1007\/BF01239496","article-title":"Engineering classification of rock masses for the design of tunnel support","volume":"6","author":"Barton","year":"1974","journal-title":"Rock Mech."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/S1365-1609(02)00011-4","article-title":"Some new Q-value correlations to assist in site characterisation and tunnel design","volume":"39","author":"Barton","year":"2002","journal-title":"Int. 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