姓名 |
曾淑瑜(Shu-Yu Zeng)
查詢紙本館藏 |
畢業系所 |
土木工程學系 |
論文名稱 |
探討人造軟岩節理面粗糙度與其剪力強度關係
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相關論文 | |
檔案 |
[Endnote RIS 格式]
[Bibtex 格式]
[相關文章] [文章引用] [完整記錄] [館藏目錄] 至系統瀏覽論文 (2025-10-1以後開放)
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摘要(中) |
岩體中的節理面構造不止影響岩體的本身材料強度,節理面粗糙度係數(JRC)也會影響岩體整體的剪力強度。Barton(1977)提出以視覺對照法判斷JRC,惟此判斷法較為主觀,近年來已有許多學者提出利用數值量化的方式評估JRC。為了更瞭解節理面粗糙程度與 JRC 值的關聯,魏培杰(2015)、廖明傑(2017)、羅宇軒(2018)蒐集並數位化 136 條岩石節理剖面,針對剖面高程差之標準差對其進行統計分析,迴歸出標準差與 JRC 的關係式。
本研究利用其關係式隨機產生 JRC=3、JRC=10、JRC=19.6 之剖面,利用 3D 列印技術列印出模型,並採用石膏與石英砂的複合材料灌製翻模符合指定節理面粗糙度的人造軟岩。上述人造節理面試體皆進行下列兩個步驟:(1)利用文獻中的四種 JRC 估算法驗證是否接近指定 JRC。(2)在正向力為0.5MPa、1.0MPa、 2.0MPa 下進行直剪試驗,以了解人造軟岩之節理試體在給定 JRC 下,其剪力強度是否亦符合 Barton 建議之公式。
研究結果顯示:(1)翻模後的人造軟岩節理面,其剖面 JRC 相較於指定JRC 更小,其原因可能與石膏試體於養治過程之收縮有關;(2) 以Barton經驗公式,並依試體真實 JRC 以及其單壓強度,推估之剪力強度與實驗之尖峰剪力強度差異百分比為 20%以內,顯示其人造軟岩之節理面剪力強度可大致以公式推估。(3)試體受剪後之破壞面積比與正向應力為正相關,試體JRC 對其較無影響。(4)低粗糙度試體在受剪後粗糙度會提高,高粗糙度試體受剪後其粗糙度會降低。
本研究也利用 PFC 軟體進行人造軟岩之單壓模擬及直剪模擬,以更進一步分析直剪試體之微觀力學行為,以單壓試驗為數值模型驗證之目標,為數值模型取得校正參數,並以此參數進行人造軟岩節理面之直剪模擬。
數值模擬結果顯示:(1)單壓模擬得到之結果與物理實驗高度吻合,包含其勁度、波松比以及尖峰強度。(2)以單壓模擬所得之數值參數進行直剪試驗模擬,直剪模擬結果之尖峰剪應力與勁度皆遠大於物理實驗,且破壞產狀與物理實驗不符。(3)以改善後之數值參數,其直剪模擬之尖峰剪應力及勁度已大致符合物理實驗,此結果亦顯示不同破壞機制之模擬,其參數亦可能有所不同。 |
摘要(英) |
The mechanical strength of the rock mass is affected by the joint surface structure and the joint surface roughness coefficient (JRC). Barton (1977) proposed an empirical chart to estimate the JRC by visual classification, but this method seems subjective. In recent years, many researchers have proposed using analytical methods to evaluate JRC more objectively. To better understand the relationship between the roughness of the joint surface and the JRC value, prior researchers in our group collected and digitized 136 rock joint profiles and performed statistical analysis on the standard deviation of the profile elevation difference. As a result, a relationship between the standard deviation and JRC profile height difference was proposed and proved valid.
In this study, the joint profiles of JRC=3, JRC=10, and JRC=19.6 were randomly generated by the proposed equation, and the cast model was printed using 3D printing technology.In addition, a large amount of artificial gypsum soft rock specimens was prepared by pouring the material into the model. We used these artificial soft rock jointed specimens to perform the following tasks: (1) Use the existing JRC estimation methods to verify the jointed specimen with the specified JRC values. (2) Carry out the direct shear tests under the normal stresses of 0.5MPa, 1.0MPa, and 2.0MPa.
The research results showed that: (1) the actual JRC of the artificial soft rock joint surface after curing is much smaller than that of the specified JRC (2) the peak shear strength estimated by the Barton empirical formula and the direct shear test is comparable. The percentage difference is within 20%. (3) The failure area ratio of the specimen after shearing is positively correlated with the normal stress, and the JRC of the specimen does not affect the failure area ratio. (4) The roughness of the low-JRC specimen is higher after shearing, and the roughness of the high-JRC specimen is reduced after shearing.
This study also uses PFC software to simulate artificial soft rock for uniaxial compression and direct shear tests to analyze the micromechanical behavior. In addition, the physical uniaxial compression test was used to verify the numerical parameters in the PFC model, and the direct shear simulation was carried out with these parameters.
The numerical simulation results show that: (1) The results obtained from the uniaxial compression simulation are highly consistent with the physical experiments. (2) The direct shear simulation was first carried out using the verified parameters by a uniaxial compression test. As a result, the peak shear stress and stiffness of the simulation results are much larger than those of the physical experiment, and the failure conditions of the specimen are also inconsistent with the physical experiment. (3) The numerical parameters were modified to improve the simulation, as mentioned in earlier results. The peak shear stress and stiffness of the direct shear simulation are roughly in line with the physical experiments. |
關鍵字(中) |
★ 人造軟岩 ★ 3D列印 ★ 節理面粗糙度 ★ 直剪試驗 ★ 離散元素法 |
關鍵字(英) |
★ Jointed soft rock ★ 3D printing ★ JRC ★ Direct shear test ★ distinct element method |
論文目次 |
圖目錄 vii
表目錄 x
符號表 xi
第一章 緒論 1
1.1 研究背景 1
1.2 研究目的 2
1.3 研究流程 3
第二章 文獻回顧 4
2.1 岩石節理面力學性質 4
2.2 岩石節理面粗糙度定義 4
2.2.1 標準節理面剖面對照 4
2.2.2 方均根法 5
2.2.3 傾角擬合法 6
2.2.4 碎形維度法 8
2.3 人造岩石節理面之剪力強度 9
2.3.1 人造岩石之單壓強度 10
2.3.2 人造岩石之基本摩擦角 10
2.3.3 人造岩石之剪力強度 11
2.4 隨機產生節理面之物理實驗與數值模擬 12
2.4.1 標準差與 JRC 之關係 12
2.4.2 隨機產生剖面之數值模擬 13
2.4.3 隨機產生剖面進行直剪試驗 17
第三章 研究方法 20
3.1 產生指定 JRC 的節理面 20
3.2 人造岩石材料 22
3.3 岩石直接剪力試驗 23
3.3.1 翻模用模具製作方法 23
3.3.2 人造節理面試體灌製 25
3.3.3 製作基本摩擦角量測試體 25
3.3.4 試驗配置及步驟 26
3.4 單軸抗壓試驗 27
3.4.1 試體製作 27
3.4.2 試驗步驟及配置 28
第四章 隨機產生節理面-物理力學行為 30
4.1 隨機產生節理面 JRC 分佈 30
4.2 單軸壓縮試驗結果 37
4.3 岩石直接剪力試驗結果 38
4.3.1 基本摩擦角 38
4.3.2 隨機產生節理面剪力強度 40
4.4 節理面受剪後產狀分析 47
4.4.1 節理面受剪後破壞面積比 47
4.4.2 節理面受剪後 JRC 變化 60
第五章 單壓與直剪試驗之數值分析 66
5.1 PFC 基本理論 66
5.1.1 線性接觸模式 68
5.1.2 平行鍵結模式 69
5.1.3 平滑節理接觸模式 70
5.2 人造軟岩之單壓試驗模擬 72
5.3 隨機產生節理面之直剪模擬 75
5.3.1單壓模擬參數模擬直剪試驗 75
5.3.2修正單壓試驗參數進行直剪模擬 82
第六章 結論與建議 88
6.1 本研究之建議 88
6.2 未來建議 89
參考文獻 90
附錄 92
問題與討論 92 |
參考文獻 |
1. 魏培杰,「不同粗糙度係數下岩石節理面剖面之空間變異性探討」,國立中央大學土木工程學系研究所碩士論文,中壢(2015)
2. 廖明傑,「岩石節理面之隨機模擬與其離散元素模型之力學性質分析」,國立中央大學土木工程學系研究所碩士論文,中壢(2017)
3. 羅宇軒,「以隨機產生之岩石節理面進行數值模擬與直剪試驗」,國立中央大學土木工程學系研究所碩士論文,中壢(2018)
4. 黃文泓,「電腦輔助製造節理剖面之剪力強度規模效應」,國立台灣大學土木工程學系研究所碩士論文,台北(2000)
5. 簡志峻,「以物理試驗及數值耦合分析探討 3D 列印地工格網於軟弱土壤之加勁機制」,國立中央大學土木工程學系研究所博士論文,中壢(2018)
6. 董詠濬,「以離心機及數值模型探討延續性對多節理岩坡楔型塊體之破壞機制」,國立中央大學土木工程學系研究所碩士論文,中壢(2018)
7. Barton, N. and V. Choubey "The shear strength of rock joints in theoryand practice." Rock mechanics 10(1-2): 1-54(1977).
8. Grasselli, G. and P. Egger "Constitutive law for the shear strength of rock joints based on three-dimensional surface parameters." International Journal of Rock Mechanics and Mining Sciences 40(1): 25-40(2003).
9. Itasca Consulting Group Inc., 2017. PFC3D (Particle Flow Code in 2 Dimensions), Version 5.0. Minneapolis, MN: ICG. (2017)
10. JANG, B.A. et al. “A new method for determination of joint roughness coefficient.” Proceedings of the 10th Congress of the International Association for Engineering Geology and the Environment, September 6-10, Nottingham, United Kingdom, No. 95(2006).
11. Lee, Y. H., et al. "The fractal dimension as a measure of the roughness of rock discontinuity profiles." International Journal of Rock Mechanics and Mining Sciences & Geomechanics, 27(6): 453-464(1990).
12. Tatone, B. S. A. and G. Grasselli. "A new 2D discontinuity roughness parameter and its correlation with JRC." International Journal of Rock Mechanics and Mining Sciences 47(8): 1391-1400(2010).
13. Tse, R. and D. M. Cruden. "Estimating joint roughness coefficients." International Journal of Rock Mechanics and Mining Sciences & Geomechanics, 16(5): 303-307 (1979). |
指導教授 |
黃文昭(Wen-Chao Huang)
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審核日期 |
2022-9-29 |
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