Time dependent behavior of discontinuities and its relationship with long-term strength

• 資料種別: 博士論文
• タイトル: Time dependent behavior of discontinuities and its relationship with long-term strength
• 著者・編者: Liu, Ang
• 著者標目: Liu, Ang
• 出版年月日等: 2019-03-06
• 出版年（W3CDTF）: 2019-03-06
• 並列タイトル等: 応力緩和・クリープ試験に基づく岩石不連続面の長期挙動に関する研究
• 授与機関名: 徳島大学
• 授与年月日: 2019-03-06
• 授与年月日（W3CDTF）: 2019-03-06
• 報告番号: 甲第3286号
• 学位: 博士（工学）
• 博論授与番号: 甲第3286号
• 本文の言語コード: eng
• 件名標目: Discontinuity; Stress relaxation; ICLM; Creep; Long-term strength; discontinuities; artificial rocks
• 対象利用者: 一般
• 一般注記: Rock mass, as an engineering material, is a complex geological material containing numerous discontinuities such as geological faults, joints, fractures, etc. Discontinuities are among the most important factors that governing the mechanical behavior of a rock mass. Investigated data has demonstrated that the failure of the rock engineering along discontinuities is always not a brittle behavior but progressive damage after years or decades by creep and stress relaxation. Currently, intensive emphasis has been put on studying the time-dependent behaviors of rock masses through laboratory creep tests. However, stress relaxation behaviors and its correlation with long-term strength has been rarely investigated.A series of conventional shear tests, shear creep tests and shear relaxation tests under different normal stresses were performed on artificial discontinuities with different Joint Roughness Coefficient (JRC). Special interests of this study are given to understand the time dependent behaviors of discontinuities, especially stress relaxation behaviors, and their relationship with long-term strength of discontinuities.The main research contents are as follows:1) A series of conventional shear tests on discontinuities with various normal stresses and JRC were conducted to explore the shear mechanical behaviors impacted by normal stress and JRC.2）A series of stepwise shear creep tests of discontinuities were conducted, and evolutions of creep and creep rates are analyzed. Accordingly, an improved K-B model was proposed to describe the creep characteristics of discontinuities, and the fitting results present a good agreement with test results.3) The isostress cyclic loading method (ICLM) was proposed to study the shear stress relaxation behaviors of discontinuities. The evolutions of stress relaxation curves under different normal stress as well as cyclic loading were analyzed. Accordingly, a nonlinear model (H-K-M) was proposed to describe the stress relaxation characteristics of discontinuities, and the fitting results agree well with test results.4) Correlation between stress relaxation behavior and long-term strength, as well as between creep behaviors and long-term strength are analyzed. Stress relaxation method is put forward and proposed to determine long-term strength of discontinuities, from which the obtained long-term strengths present a good agreement with Mohr-Coulomb shear formula. Besides, long-term strengths were also obtained by creep tests. Differences between these methods were compared, which shows that stress relaxation method is more accurate.
• 国立国会図書館永続的識別子: info:ndljp/pid/11710971; https://dl.ndl.go.jp/pid/11710971
• コレクション（共通）: 障害者向け資料
• コレクション（障害者向け資料：レベル1）: テキストデータ
• コレクション（個別）: 国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文; https://dl.ndl.go.jp/collections/A00014
• 収集根拠: 博士論文（自動収集）
• 受理日（W3CDTF）: 2021-08-09T17:15:52+09:00
• 記録形式（IMT）: application/pdf
• オンライン閲覧公開範囲: 国立国会図書館内限定公開
• デジタル化資料送信: 図書館・個人送信対象外
• 遠隔複写可否（NDL）: 可
• 掲載誌（URI）: http://repo.lib.tokushima-u.ac.jp/113313
• 連携機関・データベース: 国立国会図書館 : 国立国会図書館デジタルコレクション; https://dl.ndl.go.jp