臺灣博碩士論文加值系統

本研究為探討粒徑效果之影響，進行一系列符合平面應變變型模式之回包式牆面加勁擋土牆垂直承載力試驗。本研究之模型牆體尺寸為183cm(長)×80cm(寬)×112cm(高)。本試驗採用30公分寬之剛性條型基礎進行垂直加壓。背填材材料分別採用砂土(D50 = 0.6mm)及礫石( D50 = 10.1mm)，加勁材則採用兩種勁度相異之PET地工格網。於此模型試驗中為求擋土牆之整體行為，於加載過程中，除監測擋土牆之垂直承載力與基礎沉陷量外，並藉由影像分析方法以量測土體內部各點之位移與牆面之側向位移，並觀測出土體剪裂帶的漸進發展趨勢。本研究結果顯示，加勁土之基礎極限承載力皆較未加勁者有顯著的成長，且試驗不同標稱強度之加勁材時，標稱強度較高之試體承載力亦較高。粒徑越大之試體較粒徑小者更能大幅地提升承載力。當基礎持續被加載時，於相同的基礎垂直壓力下，未加勁試體之牆面變形皆大於加勁者之牆面變形。將影像分析結果所得之照格點變形圖、最大剪應變等值圖及零伸張壓縮應變方向向量圖進行相互對照皆可觀察出剪裂帶的漸進式發展趨勢。藉由分析最大剪應變等值圖能發現，粒徑越大之背填材其剪裂帶範圍愈大，且對應之剪應變量愈小。綜合上述試驗結果可知，基礎極限承載力、擋土牆側向牆面變形及土體剪裂帶樣式皆受粒徑效果之影響甚深。

In this study, a series of plane strain model tests on wrap-faced geogrid-reinforced soil (GRS) retaining wall were conducted. Two types of coarse-grained soils, namely, sand and gravel, were adopted as the backfills of GRS retaining wall. Two types of geogrids having different nominal strengths were used. The dimensions of the model wall were 183 cm (width) × 80 cm (depth) × 112 cm (height). A strip footing of 30 cm wide, having its setback distance equal to 50cm was located on the surface of backfill to resist the applied vertical load during model test. The vertical pressure and displacement of footing base were measured in the tests.Besides, by using photogrammetricanalysis method, the deformation patterns of soil particle, the lateral movement of facing and the progressive failure process of soil based on the calculated shear straincontours were also obtained. The test results indicated that compared to unreinforced soil, the bearing capacity of reinforced soil was increased and the higher stiffness of reinforcement the higher value of bearing capacity. Under the same footing pressure, the lateral movement of facing of unreinforced soil was larger than that of reinforced one. The figure of deformed grid point, the contour of maximum shear strain and vector of the zero-extension line of soil all revealed the process of progressive shear failure of retaining wall. The larger mean particle size the wider area of shear zone and lower value of its corresponding shear strain. To sum up, the ultimate bearing capacity, the lateral deformation of facing and the deformation pattern of wrap-faced retaining wall were found to be significantly influenced by the mean particle size of backfill.

摘要
ABSTRACT
目錄
表目錄
圖目錄
第一章 緒論
1.1 研究動機及目的
1.2 研究方法
1.3 研究內容
第二章 文獻回顧
2.1 加勁擋土牆介紹與基本原理
2.2 加勁土的加勁機制
2.2.1 直接剪力試驗
2.2.2 拉出試驗
2.2.3 平面應變試驗
2.3 粗顆粒土壤之粒徑效果
2.4 加勁擋土牆模型試驗之變形與破壞機制的觀測
第三章 模型試驗與儀器介紹
3.1 前言與模型試驗介紹
3.2 擋土牆模型介紹
3.3 MTS垂直加載系統
3.4 試驗材料
3.4.1 背填材料
3.4.2 安息角試驗
3.4.3 地工合成材
3.5 擋土牆模型試體與牆面變形之量測方式
3.5.1 影像設備
3.5.2 橡皮膜與矽利康油脂
3.5.3 牆面形式
3.6 模型試驗使用之相關器具
3.6.1 搬運器材
3.6.2 夯實機
3.6.3 捲揚機
3.6.4 資料擷取系統
第四章 加勁擋土牆試驗規劃與方法
4.1 加勁擋土牆試驗填築流程
4.1.1 擋土牆試驗填築前準備事項
4.1.2 擋土牆試驗填築流程
4.1.3 儀器架設與試體加載過程
4.1.4 試驗後處理事宜
4.2 以影像分析方法計算土體應變
4.2.1 照片分析前處理
4.2.2 橡皮膜點位之座標擷取
4.2.3 擋土牆內部變形之應變量計算
4.2.4 剪裂帶繪製
4.3 以影像分析方法處理牆面水平位移
4.4 試驗規劃
第五章 試驗結果與討論
5.1 基礎承載力曲線
5.1.1 地工格網標稱強度大小之影響
5.1.2 背填材粒徑大小之影響
5.1.3 安息角關係
5.1.4 綜合討論
5.2 擋土牆之牆面變形
5.2.1 基礎於相同沉陷量下牆面變形之樣式
5.2.2 基礎於相同承載力下牆面變形之樣式
5.2.3 綜合討論
5.3 擋土牆內部之變形模式
5.3.1 數位化格點變形圖
5.3.2 最大剪應變γmax等值圖
5.3.3 零伸張壓縮應變方向向量圖
5.3.4 剪裂帶發展樣式圖
5.3.5 綜合討論
5.4 加勁材拉出破壞樣式
第六章 結論與建議
6.1 結論
6.2 建議
參考文獻
附錄A MatLab_Normal True.m
附錄B 安息角試驗
附錄C 影像分析九區域原始圖

1.FHWA, 2001, “Mechanical stability of the walls and reinforced soil slopes design and construction guidelines,” Pub. No. FHWA-NHI-00-043.

2.Gomes, R. C., Palmeria, E. M., and Lanz, D., 1994, “Failure and deformation mechanisms in model reinforced walls subjected to different loading conditions.” GeosyntheticsInternational ,Vol. 1, No. 1, pp. 45-65.

3.Jewell, R. A., Raine, N., and Woods, R. I., 1984, “Design methods for steep reinforced embankments,” ProcSympOn Polymer Grid Reinforcement in Civil Engineerings, London.

4.Jewell, R. A., Milligan, G.W.E., Sarsby, R. W., and Dubois, D., 1984, “Interaction between soil and geogrids Telford,” Prooceedings of the Conference on Polymer Grid Reinforcement in Civil Engineerings, pp. 18-30.

5.Jewell, R. A., and Worth, C. P., 1987, “Direct shear tests on reinforced sand,” Geotechnique, Vol. 37, No. 1, pp. 53-68

6.Jewell, R. A., 1990, “Reinfocement bond capacity,” Geotechnique, Vol. 40, No. 3, pp. 513-518.

7.Liu, C.N., Yang, K.H., and Nguyen, M.D., 2014, “Behavior of geogrid-reinforced sand and effect of reinforcement anchorage in large-scale plane strain compression,” Geotextiles and Geomembranes, Vol. 42, pp. 479-493.

8.Liu, C.N., Ho, Y.H., and Huang, J.W.,2009,“Large scale direct shear tests of soil/PET-yan geogrid interfaces,”” Geotextiles and Geomembranes, Vol. 27, pp. 19-30.

9.Michalowski, R. L., and Shi, L., 2003, “Deformation Patterns of Reinforced Foundation Sand at Failure,” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, pp. 439-449.

10.Palmeira, E. M., 2009, “Soil-geosynthetic interaction: modeling and analysis, ”Geotextiles and Geomembranes, Vol. 27, pp. 368-390.

11.Tatsuoka, F., Nakamura, S., Huang, C-C., and Tani, K., 1990, “Strength anisotropy and shear band direction in plane strain tests on sand,” Soils and Foundations, Vol. 30, No. 1, pp. 35-54.

12.Tensar International, 2009, TensarGeosynthetics in Civil Engineering, Tensar International Ltd., Blackum.

13.Wang, J. J., Zhao, D., Liang, Y., and Wen, H.B., 2013, “Angle of repose of landslide debris deposits induced by 2008 Sichuan Earthquake,”Engineering Geology, Vol. 156, pp. 103-110.

14.Wu, J. T. H., 1994, “Design and Construction of Low Cost Retaining Walls-The Next Generation in Technology,”Colorado transportation institute, U. S. A.

15.Yamamoto, K., Kusuda, K., 2001, “Failure mechanisms and bearing capacities of reinforced foundations,” Geotextiles and Geomembranes, Vol. 19, pp. 127-162.

16.Yoshida, T., and Tatsuoka, F., 1997, Deformation property of shear band in sand subjected to plane strain compression and its relation to particle characteristics, Proc. 14th ICSMFE, Hamburg, Vol. 1, pp. 237-240.

17.Zhou, J., Chen, J.-F., Xue, J.-F., Wang, J. Q., 2012,“Micro-mechanism of the interaction between sand and geogridtransverse ribs,”Geosynth. Int.Vol. 19, No. 6, pp.426-437.

18.日本地盤工學會, 1986, 補強土工法。

19.吳尚哲，2007，粗粒徑土壤加勁擋土牆大型模型試驗程序之測試，國立雲林科技大學，碩士論文。
20.王宸豐，2009，回包式加勁擋土牆之加載試驗，國立雲林科技大學營建工程系，碩士論文。
21.陳漢生，2009，地工格網勁度與土壤粒徑對加勁擋土牆承載力與變形之影響，國立雲林科技大學營建工程系，碩士論文。
22.施昀昇，2010，砂礫回填土加勁擋土牆模型試驗與穩定分析，國立雲林科技大學營建工程系，碩士論文。
23.李宗翰，2012，砂質回填土回包式加勁擋土牆加載試驗與其破壞樣式之觀察，國立雲林科技大學營建工程系，碩士論文。
24.林欽勝，2012，礫石回填土回包式加勁擋土牆加載試驗與其破壞樣式之觀察，國立雲林科技大學營建工程系，碩士論文。
25.楊哲瑋，2014，回包式牆面地工格網加勁擋土牆之牆面變形，國立雲林科技大學營建工程系，碩士論文。