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研究生： 戴裕聰
Yu-Tsung Tai
論文名稱： 土壤吸力對路基土壤之力學特性影響探討
指導教授： 李崇正
Chung-Jung Lee
黃偉慶
Wei-Hsing Huang
口試委員:
學位類別： 碩士
Master
系所名稱： 工學院 - 土木工程學系
Department of Civil Engineering
畢業學年度： 92
語文別： 中文
論文頁數： 99
中文關鍵詞： 土壤吸力 、濾紙法 、不飽和土壤 、回彈模數
外文關鍵詞： unsaturated soil, resilient modulus, soil suction, filer paper method
相關次數： 點閱：9  下載：0 
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    • 台灣地處亞熱帶地區，頻繁的季節性變化可能是影響鋪面成效的關
    鍵，但因國內缺乏長期鋪面成效觀測數據，故援用美國長期鋪面成效觀測
    計劃LTPP (Long Term Pavement Performance) 資料庫軟體(DataPave 3.0)中
    現地觀測資料，擷取現地數據，探討季節性環境變化如降雨、凍融、地下
    水位昇降等對路基土壤行為特性的影響，結果發現路基土壤含水量會受到
    季節性降雨影響而產生變動。以凝聚性土壤而言，變動多於最佳含水量
    (Optimum Moisture Content, OMC)濕側，變動範圍小於3 %之內，此因乃土
    壤自身組構能力與環境達到一平衡狀態，此稱平衡含水量(Equilibrium
    moisture content, EMC)。回彈模數會因為降雨引致含水量的增加而折減，
    變化趨勢及反應時間上與降雨歷時曲線較相似。
    路基土壤地層位置因常位於地下水位面以上，而呈現不飽和狀態。土
    壤在不飽和狀態時，土壤吸力是一項重要的參數，因土壤有效應力會受到
    土壤吸力(Soil Suction)作用而改變，利用實驗室夯實試體，控制不同單位
    重及含水量變化，進而模擬現地路基土壤自建造時OMC 狀態至鋪面開通
    服務後，在現地環境所受之應力狀態及EMC 對回彈模數的影響，並利用
    濾紙法(Filter Paper Method)量測不飽和土壤之吸力強度，結果發現土壤吸
    力會隨含水量增加及相對夯實度的降低而折減。
    實驗結果藉由建立回彈模數-土壤吸力模式能有效預測路基土壤回彈
    模數受季節性變因之變動，取代繁鎖且昂貴的回彈模數試驗，幫助對現地
    回彈模數的預測及監控，而影響路基土壤回彈模數的因子，依權重大小依
    序為土壤單位重、土壤吸力、應力狀態，故建構時夯實度的控制，可能是
    將來鋪面成效的一項重要因素。

    Moisture content of pavement materials plays a significant role in the
    performance of pavements. Variation in moisture content in the subgrade can
    induce volume change of swelling soil and result in detrimental deformation to
    the pavement structure. An increase in moisture content of the subgrade and
    unbound subbase/base often results in decreases in the bearing capacity of
    these materials, weakens the pavement’s response to loads, and reduces
    pavement service life.
    Soil suction will affect the mechanical properties of unsaturated soils
    much, such as effective stress, resilient modulus, and strength. This study
    attempted to collect information from LTPP database and study the climatic
    model of subgrade soil under seasonal environmental variation. Resilient
    modulus tests were conducted for 2 cohesive subgrade soils at a range of water
    contents that is likely to occur in the field. Also, soil suction was determined by
    filter paper method at various water contents to correlate with the resilient
    modulus test results.
    Experimental results indicate that: (1) field water content of cohesive soils
    are found to remain in the wet side of OMC, while that of granular soils varies
    in both the wet and dry side of OMC; (2) the resilient modulus of cohesive
    soils reduces sharply with increasing water content and decreasing degree of
    compaction; (3) the relative compaction of subgrade during construction is of
    great importance and may affect the performance of pavements; (4) the matric
    suction was found to be a good indicator of the stiffness of the subgrade and is
    used to establish a model for predicting the resilient modulus of subgrade with
    varying water contents; (5) the dry unit weight of soil also plays an important
    role in the resilient modulus-matric suction model.

    第1 章 緒論...................................................................................................... 1 1.1. 研究動機與目的.................................................................................. 1 1.2. 研究內容.............................................................................................. 2 1.3. 研究架構與流程.................................................................................. 2 第2 章 文獻回顧.............................................................................................. 5 2.1. 季節性環境變因對路基土壤的影響.................................................. 5 2.1.1. 路基土壤水文循環與路基土壤含水量.......................................... 6 2.1.2. 季節性變動對土壤行為影響的模擬.............................................. 8 2.2. 回彈模數試驗與2002 AASHTO Design Guide................................. 9 2.3. 不飽和土壤力學行為........................................................................ 10 2.4. 實驗室模擬不飽和土壤.................................................................... 12 第3 章 現地不飽和土壤模擬........................................................................ 17 3.1. 美國長期鋪面成效觀測計劃 LTPP 與 DataPave.......................... 17 3.1.1. 擷取DataPave 資料探討現地含水量變化................................... 18 3.1.2. 結果與討論.................................................................................... 19 3.1.3. 平衡含水量 (Equilibrium Moisture Content, EMC) .................... 25 3.2. 實驗室模擬現地EMC 狀態............................................................. 26 3.2.1. 試驗材料與試體準備.................................................................... 27 3.2.2. 夯實試驗........................................................................................ 28 3.2.3. 試體製作方式的差異.................................................................... 28 3.2.4. 飽和度對回彈模數的影響............................................................ 29 3.3. 改良式試體濕治分裂模.................................................................... 29 3.3.1. 模擬條件........................................................................................ 31 3.3.2. 現地土壤模擬................................................................................ 31 3.3.2.1. 現地EMC 含水量模擬.......................................................... 32 3.3.2.2. 過渡狀態模擬......................................................................... 35 3.3.3. 試體含水量均勻性測試................................................................ 37 3.4. 濾紙法(Filter Paper Method)量測土壤吸力..................................... 39 3.4.1. 試驗步驟........................................................................................ 41 3.4.1.1. 校正曲線的建立..................................................................... 41 3.4.1.2. 試體土壤吸力的量測............................................................. 48 3.4.2. 結果與討論.................................................................................... 50 3.4.2.1. 校正曲線比較......................................................................... 50 3.4.2.2. 濾紙中有機質對濾紙法的影響............................................. 51 第4 章 回彈模數與土壤吸力........................................................................ 53 4.1. 回彈模數試驗.................................................................................... 53 4.1.1. 回彈模式........................................................................................ 57 4.1.2. 試驗流程及結果分析.................................................................... 58 4.1.3. 試驗數據........................................................................................ 59 4.1.4. 小結................................................................................................ 71 4.2. 土壤吸力試驗.................................................................................... 71 4.2.1. 試驗結果........................................................................................ 72 4.3. 土壤吸力與回彈模數行為探討........................................................ 76 4.3.1. 土壤回彈模數與土壤吸力預測模式............................................ 79 4.3.2. 迴歸結果與土壤關係討論............................................................ 80 4.4. 回彈模數與LVDT 架設方式及位置............................................... 84 4.4.1. 內置式LVDT 架設........................................................................ 85 4.4.2. 實驗結果........................................................................................ 89 4.4.3. 修正模式........................................................................................ 91 4.4.4. 小結................................................................................................ 92 第5 章 結論與建議........................................................................................ 94 5.1. 結論.................................................................................................... 94 5.1.1. 季節性環境變因對路基土壤的影響............................................ 94 5.1.2. 土壤吸力與回彈模數關係............................................................ 94 5.1.3. LVDT 架設位置回彈模數的影響................................................. 95 5.2. 建議.................................................................................................... 96 參考文獻........................................................................................................... 97 圖 1.1 研究架構流程圖..................................................................................... 4 圖 2.1 路基土壤水文循環示意圖(Hossain et. al., 1997) ................................. 6 圖 2.2 LTPP 資訊管理系統中路基土壤含水量變化範圍.............................. 7 圖 2.3 路基土壤回彈模數定義........................................................................ 9 圖 2.4 典型土壤水分特性曲線...................................................................... 11 圖 2.5 Uzan (1998)模擬環境影響裝置.......................................................... 14 圖 2.6 Tadkamalla (1995)模擬環境影響裝置................................................ 15 圖 3.1 Site 48-4143 含水量與回彈模數隨時間變化情形............................. 21 圖 3.2 Site 13-1005 含水量與回彈模數隨時間變化情形............................. 21 圖 3.3 Site 48-1122 含水量與回彈模數隨時間變化情形............................. 22 圖 3.4 Site 24-1634 含水量與回彈模數隨時間變化情形............................. 22 圖 3.5 Site 48-1077 含水量與回彈模數隨時間變化情形............................. 23 圖 3.6 Site 35-1112 含水量與回彈模數隨時間變化情形............................. 23 圖 3.7 LTPP 中二個測站之降雨量與回彈模數變化關係............................ 24 圖 3.8 土壤試體濕治分裂模詳圖.................................................................. 30 圖 3.9 濕治模及不織布架設.......................................................................... 32 圖 3.10 A-7-6 土壤濕治裝置架設.................................................................. 33 圖 3.11 A-7-6 土壤不同夯實度濕治結果...................................................... 34 圖 3.12 A-2-7 土壤於不同夯實度濕治結果.................................................. 34 圖 3.13 PVC 膠膜包覆濕治裝置.................................................................... 36 圖 3.14 試體濕治配置圖................................................................................ 37 圖 3.16 切除試體端部較濕潤部位................................................................ 39 圖 3.15 試體取樣位置配置............................................................................ 38 圖 3.17 總吸力對應不同相對濕度關係........................................................ 42 圖 3.18 相對濕度對應不同吸力關係............................................................ 43 圖 3.19 純水中飽和蒸汽壓受溶質濃度影響............................................... 44 圖 3.20 濾紙進行校正試驗儀器配置............................................................ 47 圖 3.21 濾紙進行校正試驗儀器照片............................................................ 47 圖 3.22 氯化鈉溶液建立之實驗室校正曲線............................................... 48 圖 3.23 濾紙法量測土壤吸力試驗裝置配置............................................... 49 圖 3.24 濾紙校正曲線比較............................................................................ 51 圖 3.25 接觸式試驗之濾紙表面因有機質作用而生成黑斑....................... 52 圖 3.26 未接觸式試驗之濾紙未產生黑斑.................................................... 52 圖 4.1 荷重延時及週期示意圖...................................................................... 54 圖 4.2 試驗加載過程力量與變位波型.......................................................... 55 圖 4.3 A-2-7 土壤於OMC 含水量下之遲滯圈............................................. 60 圖 4.4 A-7-6 土壤於OMC 含水量下之遲滯圈............................................. 60 圖 4.5 A-2-7 土壤相對夯實度100%，試體含水量與回彈模數關係.......... 62 圖 4.6 A-2-7 土壤相對夯實度95 %，試體含水量與回彈模數關係........... 63 圖 4.7 A-2-7 土壤相對夯實度88 %，試體含水量與回彈模數關係........... 64 圖 4.8 A-2-7 土壤OMC 含水量，不同夯實度之回彈模數......................... 65 圖 4.9 A-2-7 土壤於不同夯實度下，試體含水量與回彈模數關係............ 66 圖 4.10 A-7-6 土壤相對夯實度100%，試體含水量與回彈模數關係........ 67 圖 4.11 A-7-6 土壤相對夯實度95%，試體含水量與回彈模數關係.......... 68 圖 4.12 A-7-6 土壤於相對夯實度88%，試體含水量與回彈模數關係...... 69 圖 4.13 A-7-6 土壤於OMC 含水量下，不同夯實度之回彈模數............... 70 圖 4.14 A-7-6 土壤於不同夯實度下，試體含水量與回彈模數關係.......... 70 圖 4.15 A-7-6 土壤不同夯實度與土壤吸力關係.......................................... 73 圖 4.16 A-2-7 土壤不同夯實度與土壤吸力關係.......................................... 74 圖 4.17 A-7-6 土壤孔隙率與土壤吸力關係.................................................. 75 圖 4.18 A-2-7 土壤孔隙率與土壤吸力關係.................................................. 75 圖 4.19 含水量與回彈模數對應關係(Naji, et. al., 2003) ............................. 78 圖 4.20 土壤總吸力與基質吸力對回彈模數的關係................................... 79 圖 4.21 A-7-6 土壤模式一迴歸預測與量測值比較...................................... 82 圖 4.22 A-7-6 土壤模式二迴歸預測與量測值比較...................................... 83 圖 4.23 A-2-7 土壤模式一迴歸預測與量測值比較...................................... 83 圖 4.24 A-2-7 土壤模式二迴歸預測與量測值比較...................................... 84 圖 4.25 回彈模數試驗用三軸裝置與LVDT 架設詳圖............................... 86 圖 4.26 橡皮膜進行預處理及黏貼錫箔........................................................ 87 圖 4.27 釘針穿透內置式LVDT 架設裝置................................................... 88 圖 4.28 內置式LVDT 裝置架設完成圖....................................................... 88 圖 4.29 OMC 狀態下內置與外置式量測結果比較...................................... 89 圖 4.30 過渡含水量狀態下內置與外置式量測結果比較........................... 90 圖 4.31 EMC 狀態下內置與外置式量測結果比較....................................... 91 表 次 表 3.1 試驗路段路基土壤性質...................................................................... 20 表 3.2 試驗路段建造時間與平衡含水量..................................................... 26 表 3.3 試驗土壤基本物理性質及土壤分類................................................. 27 表 3.4 台灣省道斷面設計特性...................................................................... 31 表 3.5 夯實度與土壤最終EMC 關係*.......................................................... 35 表 3.6 濕治後均勻性試驗結果...................................................................... 38 表 3.7 不同濃度氯化鈉溶液對應之吸力..................................................... 46 表 4.1 荷重延時與頻率的規定(sec).............................................................. 54 表 4.2 回彈模數動態試驗要求與 MTS-810 系統能力比較....................... 55 表 4.3 T 292-91 預處理及回彈模數試驗程序(kPa) ...................................... 56 表 4.4 A-2-7 土壤相對夯實度與含水量關係................................................ 61 表 4.5 A-7-6 土壤相對夯實度與含水量關係................................................ 66 表 4.6 式(4-7)模式一迴歸分析結果.............................................................. 81 表 4.7 式(4-8)模式二迴歸分析結果.............................................................. 81 表 4.8 不同量測位置於各軸差應力作用下之回彈模數............................. 92

    ASTM Standard, 2000, D5298-94: Standard Test Method for the Measurement
    of Soil Potential (Suction) Using Filter Paper, Annual Book of ASTM
    Standards, Vol. 04.09, Soil and Rock ( ): D4943 Ⅱ -latest, ASTM
    International, West Conshohocken, PA, pp. 1113-1118.
    AASHTO, (1992). Designation: T292-91; Standard Method of Test for
    Resilient Modulus of Subgrade Soils and Untreated Base/Subbase
    Materials, American Association of State Highway and Transportation
    Officials.
    Carmichael, R.F. III and Stuart. E. (1985). “Predicting resilient modulus: a
    study to determine the mechanical properties of subgrade soils.”
    Transportation Research Record 1043, pp. 145-148.
    Elliott, R.P., and, Thornton, S.I. (1986). “Resilient modulus-what does it
    mean?” Proceedings 37th Highway Geology Symposium, Helena, Montana,
    pp. 283-301.
    Elfino, M. K., and Davidson, J. L. (1989). “Modeling field moisture in resilient
    moduli testing.” Geotechnical Special Publication 24 (D. J. Elton and R. P.
    Ray, eds.), ASCE, pp. 31-51.
    Guan, Y., Drumm, E. C., and Jackson, N. M. (1998). “Weighting factor for
    seasonal subgrade resilient modulus.” Transportation Research Record
    1619, pp. 94-101.
    Guymon, L. G. (1994). Unsaturated Zone Hydrology, PTR PRENTICE HALL,
    Englewood Cliffs, pp. 210-210.
    Jin, M. S., Lee, K. W., and Kovacs, W. D. (1994). “Seasonal variation of
    resilient modulus of subgrade.” Journal of Transportation Engineering,
    Vol.120, No.4, pp.603-616.
    Johnson, J. R., Berg, L. R., Chamberlain, J. E., and Cole, M. D. (1986) Frost
    Action Predictive Techniques for Roads and Airfields, A Comprehensive
    Survey of Research Findings. CREEL Report 86-18, US Army Corps of
    Engineers. Cold Regions Research & Engineering Laboratory.
    Heydinger, A. G. (2003). “Evaluation of seasonal effects on subgrade soils.”
    Transportation Research Records, Vol. 1821, pp. 47-55.
    Hillel, Daniel. (1980). Foundamentals Of Soil Physics. Academic Press, New
    York.
    http://www4.trb.org/trb/crp.nsf/All+Projects/NCHRP+9-23
    Mohammad, L.N., Puppala, A.J., and Alavilli, P. (1995). “Influence of testing
    procedure and LVDT location on resilient modulus of soils.”
    Transportation Research Record, 1462, pp. 91-101.
    Mrainho, A. F., and Stuermer, M. (2000). “The influence of the compaction
    energy on the SWCC of a residual soil.” Advances in Unsaturated
    Geotechnics, edited by Shackelford C., Houston, S., and Chang, Nien-Yin,
    ASCE, No. 99, pp. 125-141.
    Naji, K. N., Zaman, M. M., Nevels, J. B., and Mann, J. (2003). “Effect of soil
    suction of resilient modulus of subgrade soil using the filter paper
    technique.” TRB Annual Meeting CD-ROM, paper no. 00-1457.
    Noureldin, S. (1994). “Influence of Stress Level and Seasonal Variations on In
    Situ Pavement Layer Properties.” National Research Council ;
    Transportation Research Record, 1448, pp. 16-24.
    Quintus, H.V., and Killingsworth, B. (1998). “Analyses relating to pavement
    material characterization and their effects on pavementperformance.”
    FHWA, Publication No. FHWA-RD-97-085.
    Rainwate, N. R., Yoder, E. R., Drumm, C. E., and Wilson., V. G. (1999).
    “Comprehensive monitoring systems for measuring subgrade moisture
    conditions.” Journal of Transportation Engineering, Vol. 123, No. 5,
    ASCE pp. 439-448.
    Salem, H. M., Bayomy F. M., and Al-Taher, M. G. (2003). “Prediction of
    seasonal variation of subgrade resilient modulus using LTPP Data.” TRB
    Annual Meeting CD-ROM, paper no. 03-3642.
    Tadkamalla, G. B., and George, K. P. (1995). “Characterization of subgrade
    soils at simulated field moisture.” Transportation Research Record 1481,
    pp. 21-27.
    Uzan, J. (1998). “Characterization of clayey subgrade materials for mechanistic
    design of flexible pavements.” Transportation Research Record 1629, pp.
    189-196.
    Witczak, M. W., Houston, N. W., Zapata, C. E., Richter, C., Larson, G. and
    Walsh, K. (2000). Improvement of the Integrated Climatic Model for
    Moisture Content Predictions. Inter Team Technical Report (Seasonal 4),
    NCHRP 1-37 A, Arizona State University.

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