本研究係探討邊坡滑動時，滑動面上土壤可能產生之粒徑分佈變化，其中包括土壤顆粒於高覆土壓力下，受剪造成之顆粒破碎，及滑動面因逕流入滲沖蝕所造成之細粒料流失情況。而低塑性粉土與砂土一樣不具凝聚性，但在滲流過程中，顆粒易受水影響，因此沖蝕作用對於低塑性粉土造成的影響甚高，且土壤顆粒受沖蝕作用易造成土壤顆粒流失。因此，本研究利用自行研發之沖蝕直接剪力試驗儀(Seepage Flow Direct Shear device)，以里港砂製作不同細粒料含量之重模土樣，探討內部沖蝕對低塑性粉土之影響。
由各系列試驗結果可知，可印證本研究之沖蝕直剪試驗儀(SFDS)可結合直剪試驗及沖蝕試驗，使試驗結果更符合現地土壤受沖蝕作用後，力學行為之變化。
土壤內部滲流行為將導致低塑性粉土顆粒流失，而土樣試體受內沖蝕後，土樣試體會轉由粗顆粒控制，使得相同孔隙比下，沖蝕後之土樣摩擦角高於未沖蝕土樣之摩擦角，且隨孔隙比越大，土壤摩擦角越小。而於剪動與沖蝕同時施作(S test)試驗結果，在高細粒料含量之試驗土樣，與W test(剪動間距為0mm)試驗結果比較，其降伏剪力強度折減60%~70%，土壤摩擦角(ϕorig)則降低10˚~12˚，亦即說明低塑性粉土有類似於黏土的遇水軟化之行為，期可作為工程界設計規劃參考之用。

This study investigated the change of soil particle-size distribution on a sliding surface during a slope slide. An independently researched and developed Seepage Flow Direct Shear device (SFDS) and remolded soil samples with various fines content consisting of Li-Gang sand were used to examine the effects of internal erosion on low plasticity silty sand.
The study results reveal that the SFDS device can be applied to combine the direct shear test and the erosion test to further resemble the change of mechanical behaviors of in situ soil after erosion.
The behavior of soil seepage resulted in particle losses of low plasticity silty sand. Consequently, the coarse particles dominated the composition of the soil specimen after internal erosion. Therefore, under the same void ratio, the friction angle of the eroded samples exceeded that of the not eroded sample. Additionally, the void ratio was inversely proportional to the friction angle. The S test, in which the shear and erosion processes were conducted simultaneously, demonstrated that the soil samples with high fines content contained a 60%~70% lower yield shear strength and a 10˚~12˚ lower friction angle (ϕorig) than did the soil samples of the W-test (0mm of shear gap). In addition, the S test results reveal that the structure of low plasticity silty sand softens with water, exhibiting soil property similar to that of clay. The study results may serve as a reference for planning and designing in the engineering industry.

1. 經濟部中央地質調查所(1991)，「屏東縣里港地區地質鑽探與試驗工程-鑽探報告書」，屏東：力權營造有限公司。
2. 何志麟(2012)，「低塑性粉土內沖蝕性質之研究─驟變壓力差試驗狀況」，碩士論文，國立成功大學土木工程研究所。
3. 吳偉特、楊騰芳(1987)，「細粒料含量在不同程度影響因素中對台灣地區沉積性砂土液化特性之研究」，土木水利，第十四卷，第三期，第59-74頁。
4. 吳佳峻(2010)，「小林村災害歷程重現之探討」，碩士論文，國立成功大學水利及海洋工程研究所。
5. 呂銘浩(2008)，「不同砂土之阻尼比關係應用於減震箱之初步研究」，碩士論文，國立交通大學土木工程研究所。
6. 呂偉哲(2011)，「由顆粒間微觀鍵結破壞探討邊坡張力裂縫發展及塊體運動行為」，碩士論文，國立臺灣大學土木工程研究所。
7. 李政忠(2011)，「雲母細粒料含量對顆粒性土壤極限狀態參數之影響」，碩士論文，國立成功大學土木工程研究所。
8. 沈茂松(2000)，「實用土壤力學試驗」，第七版，臺北：文笙書局。
9. 周鴻昇(1994)，「NGI單剪應力定體積與不排水狀況下砂土行為之研究」，碩士論文，國立台灣大學土木工程研究所。
10. 林昀葦(2006)，「台灣中部地區崩積層抗剪強度之簡易現地試驗」，碩士論文，國立中興大學土木工程研究所。
11. 林智偉(2006)，「無塑性細粒料對砂質土壤液化阻抗之研究」，碩士論文，國立成功大學土木工程研究所。
12. 林煒喬(2011)，「不同圍壓狀態對低塑性粉土內部沖蝕性質之影響」，碩士論文，國立成功大學土木工程研究所。
13. 財團法人臺灣營建研究院(2006)，「高雄捷運工程橘線CO2區段標LUO09潛盾隧道坍陷原因鑑定報告」。
14. 財團法人臺灣營建研究院(2007)，「高雄捷運工程橘線CO1區段標SUO01車站連續壁滲水坍塌事故再分析與對應契約影響之研究報告」。
15. 張育誠(2012)，「地下水壓對頁岩邊坡穩定影響之研究」，碩士論文，國立成功大學土木工程研究所。
16. 許琦、吳佳宜、潘建宏(2006)，「剪力盒間隙對礫石剪力強度之影響」，岩盤工程研討會論文集，第31-40頁，台南。
17. 陳澤仁(1987)，「砂土顆粒破碎效應與其剪力強度之關係」，碩士論文，國立臺灣大學土木工程研究所。
18. 陳俊吉(2013)，「低塑性粉土工程性質之研究」，博士論文，國立成功大學土木工程學研究所。
19. 陳宣佑(2013)，「顆粒組構對低塑性粉土內沖蝕性質影響」，碩士論文，國立成功大學土木工程研究所。
20. 陳宏銘(2014)，「張力裂縫對邊坡滑動面分佈之影響研究」，碩士論文，淡江大學土木工程研究所。
21. 游家豪(2007)，「低塑性細料對粉質砂土動態性質之影響」，碩士論文，國立成功大學土木工程研究所。
22. 黃安斌、林志平、紀雲曜、古志生、蔡錦松、李德河、林炳森(2005)，「台灣中西部粉土細砂液化行為分析」，地工技術，第103期，第5-30頁。
23. 黃宏洋(2011)，「深層崩壞之行為研究─以小林村獻肚山為例」，碩士論文，國立高雄應用科技大學土木工程與防災科技研究所。
24. 黃奕誠(2014) ，「土壤內沖蝕行為探討」，碩士論文，國立成功大學土木工程研究所。
25. 黃彥翔(2014)，「顆粒破碎對粉土細砂行為影響之探討」，碩士論文，國立成功大學土木工程研究所。
26. 萬鼎工程公司(2001)，「高雄捷運紅橘線路網補充地質調查工程地質調查報告書」。
27. 葉思辰(2015)，「低塑性粉土質砂顆粒破碎狀況下力學行為探討」，碩士論文，國立成功大學土木工程研究所。
28. 鄒永銘(1985)，「端座潤滑對體積膨脹與顆粒破碎之影響」，碩士論文，國立臺灣大學土木工程研究所。
29. 廖元憶(2005)，「台灣西南沿海高細粒料含量砂土的探討」，碩士論文，國立成功大學土木工程研究所。
30. 廖泓韻(2013)，「以微觀角度探討顆粒狀材料在直剪試驗下行為」，碩士論文，國立中央大學土木工程研究所。
31. 劉全修(2008)，「台灣中南部粉土質細砂的壓縮性」，碩士論文，國立交通大學土木工程研究所。
32. 蕭吉良(2010)，「低塑性粉土內部沖蝕性質之研究」，碩士論文，國立成功大學土木工程研究所。
33. 繆建德(2015)，「低塑性粉土質砂內沖蝕狀況下力學行為探討」，碩士論文，國立成功大學土木工程研究所。
34. 謝明紋(2000)，「砂性土壤與地工止水膜直剪試驗尺寸與承壓效應之研究」，碩士論文，國立屏東科技大學土木工程研究所。
35. 謝忠勤(2002)，「不同塑性黏土不排水剪力強度之研究」，碩士論文，國立成功大學土木工程研究所。
36. 蘇聖惟(1999)，「砂土排水與不排水受剪行為之比較」，碩士論文，國立台灣大學土木工程研究所。
37. 行政院農委會(2003)，「水土保持技術規範」。
38. 陳榮河、洪勇善(1999)，「崩塌地整治工法之介紹」，地工技術，第72期，第5-12頁。
39. ASTM D3080M-11 (2011), "Standard Test Method for Direct Shear Test of Soils Under Consolidated Drained Conditions", ASTM International, West Conshohocken, PA.
40. ASTM D452M-91 (2013), "Standard Test Method for Sieve Analysis of Surfacing for Asphalt Roofing Products".
41. Anubhav and Basudhar, P. K. (2013), "Interface Behavior of Woven Geotextile with Rounded and Angular Particle Sand", Journal of Materials in Civil Engineering, Vol. 25, No. 12, pp. 1970-1974.
42. Bishop, A. W. (1966), "The Strength of Soils as Engineering Materials", Geotechnique, Vol. 16, No. 2, pp. 91-130.
43. Bolton, M. D. (1986), "The Strength and Dilatancy of Sands", Geotechnique, Vol. 36, No. 1, pp. 65-78.
44. Chen, J. W., Chen, C. C., Lee, W. F. and Ishihara, K. (1993), "Study on the Engineering Properties of Non-Plastic Silty sand in Taiwan", Chinese institute of civil and hydraulic engineering, Vol. 24, No. 4, pp. 367-376.
45. Das, B. M. (2010), "Principles of Geotechnical Engineering - SI version", 7th edition, Cengage Learning, USA.
46. Erik I. Hjeldnes and Bhagwat V. K. Lavania (1980), "Cracking, Leakage, and Erosion of Earth Dam Materials", Journal of the Geotechnical Engineering Division, Vol. 106, pp.117-135.
47. Feda, J. (1973), "Stability of Natural Slopes", 8th International Conference Soil Mechanics and Foundation Engineering, Oral discussion, Session 6.
48. Gan, J. K. M., and Fredlund, D. G. and Rahardjo, H. (1988), "Determination of the Shear Strength Parameters of an Unsaturated Soil using the Direct Shear Test", Canadian Geotechnical Journal, Vol. 25, No. 3, pp. 500-510.
49. Guo, P. (2008), "Modified Direct Shear Test for Anisotropic Strength of Sand", Journal of Geotechnical and Geoenvironmental Engineering, ASCE Vol. 134, No. 9, pp. 1311-1318.
50. Hardin, B. O. (1985), "Crushing of Soil Particles", Journal of the Geotechnical Engineering Division, ASCE, Vol. 3, No. 10, pp. 1177-1192.
51. Head, K. H. (1982), "Manual of Laboratory Testing", Vol. 2, Halsted Press.
52. Head, K. H. (1986), "Manual of soil laboratory testing", Vol. 3, London: Pentech Press.
53. Holtz, R. D., Kovacs, W. D. and Sheahan T. C. (2010), "An Introduction to Geotechnical Engineering", 2nd edition.
54. Iai, M. and Luna, R. (2011), "Direct Shear Tests on JSC-1A Lunar Regolith Simulant", Journal of Aerospace Engineering, Vol. 24, No. 4, pp. 433-441.
55. Ishihara, K. (1993), "Liquefaction and Flow Failure During Earthquakes", Geotechnique, Vol. 43, No. 3, pp. 315-415.
56. Ingold, T. S. (1984), "A Laboratory Investigation of Soil-Geotextile Friction", Ground Engineering, November, pp. 21-28.
57. Ishihara, K. and Lee, W. F. (2008), "Piping Failure in Subway Construction due to Internal Erosion of Silty Sand", Fourth international conference on scour and erosion, pp. 505-512.
58. Ishihara, K. (2013), "Personal discussion".
59. Jewell, R. A. and Wroth, C. P. (1987), "Direct Shear Tests on Reinforced Sand", Geotechnique, Vol. 37, No. 1, pp. 53-68.
60. Kenney, T. C. and Lau, D. (1985), "Internal Stability of Granular Filters", Canadian Geotechnical Journal, Vol. 22, pp.215-225.
61. Kenney, T. C. and Lau, D. (1986), "Discussion on Internal Stability of Granular Filters," Canadian Geotechnical Journal, Vol. 23, pp.420-423.
62. Kiekbusch, M. and Schuppener, B. (1977), "Membrane Penetration and Its Effect on Pore Pressures", Journal of the Geotechnical Engineering Division, ASCE, Vol. 103, No. CT11, pp. 1267-1279.
63. Kim B. S., Shibuya S., Park S.W. and Kato S. (2012), "Effect of Opening on the Shear Behavior of Granular Materials in Direct Shear Test." Journal of Civil Engineering, KSCE, Vol. 16, No. 7, pp. 1132-1142.
64. Kim B. S., Shibuya S., Park S.W. and Kato S. (2013), "Suction Stress and Its Application on Unsaturated Direct Shear Test under Constantvolume Condition", Engineering Geology, Vol. 155, pp. 10-18.
65. Kokusho, T. and Fujikura Y. (2008), "Effect of Particle Gradation on Seepage Failure in Granular Soils", Fourth International Conference on Scour and Erosion, pp. 497-504.
66. Kramer, S. L. (1996), "Geotechnical Earthquake Engineering", New Jersey, Prentice Hall.
67. Lade, P. V. and Hernandez, S. B. (1977), "Membrane Penetration Effect in Undrained Tests", Journal of the Geotechnical Engineering Division, ASCE, Vol. 103, No. CT2, pp. 109-125.
68. Lade, P. V., Liggio, C. D. and Yamamuro, J. A. (1998), "Effects of Non-Plastic Fines on Minimum and Maximum Void Ratios of Sand", Geotechnical Testing Journal, ASTM, Vol. 21, No. 4, pp. 336-347.
69. Lambe, T. W. (1981), "Soil Testing for Engineers", Wiley, pp. 88-97.
70. Lambe, T. W. and Whitman R. V. (1979), "Soil Mechanics SI Version", New York: John Wiley & Sons.
71. Lee, K. L. and Farhoomand, I. (1967), "Drained Strength Characteristics of Sands", Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. 93, No. SM6, Nov., pp. 117-141.
72. Lee, K. L., and Farhoomand, I. (1967), "Compressibility and Crushing of Granular Soil in Anisotropic Triaxial Compression", Canadian Geotechnical Journal, Vol. 4, No. 1, Feb., pp. 68-86.
73. Lee, K. L. and Seed, H. B. (1967), "Drained Strength Characteristics of Sands", Journal of the Soil Mechanics and Foundations Division, ASCE Vol. 93, No. SM6, pp. 117-141.
74. Lee, K. L., Seed, H. B. and Dunlop, P. (1967), "Effect of Moisture on the Strength of a Clean Sand", Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. 93, No. SM6, Nov., pp. 17-40.
75. Lee, W. F. and Ishihara, K. (2010), "Personal communications".
76. Lee, W. F., Ishihara, K., Chen, C. C., Chen, J. W. and Chang, M. H. (2012), "Study on the Engineering Properties of Non-Plastic Silty Sand in Taiwan", Sino-Geotechnics, No. 133, Sep., pp. 7-18.
77. Lee, W. F., Chen, C. C., Chen, J. W. and Ishihara, K. (2013), "Engineering Properties of Non-Plastic Silty Sand", Sound Geotechnical Research to Practice, pp. 420-430.
78. Lee, W. F., Chen, C. C., Chen, J. W. and Ishihara, K. (2014), "Liquefaction Potential of Non-Plastic Silty Sand", Journal of Marine Science and Technology, Vol. 22, No. 2, pp. 137-145.
79. Leslie, D. D. (1963), "Large Scale Triaxial Tests on Gravelly Soils," Proceedings of the 2nd Panamerican Conference on Soil Mechanics and Foundation Engineering, Brazil, Vol. 1, pp. 181-202.
80. Leslie, D. D. (1975), "Shear Strength of Rockfill", Physical Properties Engineering Study No. 526, South Pacific Division, Corps of Engineers Laboratory, Sausalito, Calif., Oct., pp. 124.
81. Marsal, R. J. (1965), "Discussion of Shear Strength", Proceedings of the 6th International Conference on Soil Mechanics and Foundation Engineering, Montreal, Vol. 3, pp. 310-316.
82. Marsal, R. J. (1969), "Mechanical Properties of Rockfill and Gravel Materials", Proceedings of the 7th International Conference on Soil Mechanics and Foundation Engineers, Vol.3, pp.499-506.
83. Miura, N., Murata, H. and Harada, A. (1983), "Effect of Water on the Shear Characteristics of Sandy Soils Consisted of Breakable Particles", Transactions of the Japanese Society of Civil Engineering, Vol. 15, pp. 377-380.
84. Miura, S. and Kawamura, S. (1996), "A Procedure Minizing Membrane Penetration Effects in Undrained Triaxial Test", Soils and Foundations, Vol.36, No.4, pp.119-126.
85. Ouyang, M., Ke, L. and Takahashi, A. (2014), "Effects of Internal Erosion on Undrained Responses of Soils with Different Initial Fines Contents", Scour and Erosion: Proceedings of the 7th International Conference on Scour and Erosion, Perth, Australia, December, pp. 143-153.
86. Palmeira, E. M. and Milligan, G. W. E. (1989), "Scale Effects in Direct Shear Tests on Sand", Proc., 12th Int. Conf. on Soil Mechanics and Foundation Engineering, Vol. 1, No. 1, pp. 739-742.
87. Rowe, P. W. (1962), "The Stress-Dilatancy Relation for Static Equilibrium of an Assembly of Particles in Contact", Proceedings of the Royal Society, London, England, Series A, Vol. 269, pp. 500-527.
88. Scarpelli, G. and Wood, D. M. (1982), "Experimental Observations of Shear Band Patterns in Direct Shear", Proc. of the IUTAM Sym. on Deformation and Failure of Granular Materials, Vermeer, P. A. and Luger, H. J. (eds), Rotterdam: Balkema, pp. 473-484.
89. Schofield, A. (2005), "Disturbed Soil Properties and Geotechnical Design", London: Thomas Telford.
90. Sherard, J. L. (1992), "Sinkholes in Dams of Coarse, Broadly Graded Soils", Geotechnical Special Publication, No. 32, pp. 324-335.
91. Shibuya, S., Mitachi, T. and Tamate, S. (1997), "Interpretation of Direct Shear Box Testing of Sands as Quasi-Simple Shear", Geotechnique, Vol. 47, No. 4, pp. 769-790.
92. Skempton, A. W. and Brogan, J. M. (1994), "Experiments on Piping in Sandy Gravels", Geotechniqus, Vol. 44, No.3, pp. 449-460.
93. Thevanayagam, S. (1998), "Effect of Fines and Confining Stress on Undrained Shear Strength of Silty Sands", Journal of Geotechnical and Geoenvironmental Engineering, Vol. 124, No. 6, pp. 479-491.
94. Tomlinson, S. S. and Vaid, Y. P. (2000), "Seepage Forces and Confining Pressure Effects on Piping Erosion", Canadian Geotechnical Journal, Vol. 37, No.1. pp. 1-13.
95. Varnes, D. J. (1978), "Slope movement types and process: In landslides".
96. Yamamuro, J. A. and Covert, K. M.(2001), "Monotonic and Cyclic Liquefaction of Very Loose Sands with High Silt Content", Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 4, pp. 314-324.
97. Yamamuro, J. A. and Lade, P. V. (1998), "Steady-State Concepts and Static Liquefaction of Silty Sands", Journal of Geotechnical and Geoenvironmental Engineering, Vol. 124, No. 9.
98. Yamamuro, J. A. and Lade, P. V. (1999), "Experiments and Modeling of Silty Sands Susceptible to Static Liquefaction", Mechanics of Cohesive-Frictional Materials, Vol. 4, No. 6, pp. 545-564.
99. Yamamuro, J. A. and Covert, K. M. (2001), "Monotonic and Cyclic Liquefaction of Very Loose Sands with High Silt Content", Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 4, pp. 314-324.
100. Yamamuro, J. A. and Wood, F. M. (2004), "Effect of Depositional Method on the Undrained Behavior and Microstructure of Sand with Silt", Soil Dynamics and Earthquake Engineering, Vol. 24, No. 9-10, pp. 751-760.
101. Yatabe, R., Oshima, A. and Suzuki, K. (1995), "Results of Round Robin Test on Direct Shear Test", Proc., Int. Sym. on direct shear box testing of soils, pp. 1-11 (in Japanese).
102. Yin, Z. Y., Zhao, J. and Hicher, P. Y. (2014), "A Micromechanics-Based Model for Sand-Silt Mixtures", International Journal of Solids and Structures, Vol. 51, No. 6, pp. 1350-1363.
103. Zhang, J. M., Jiang G. S., and Wang, R. (2009), "Research on Influences of Particle Breakage and Dilatancy on Shear Strength of Calcareous Sands", Rock and Soil Mechanics, Vol. 30, No. 7, Jul., pp. 2043-2048.
104. Zhao, G. S., Zhou, G. Q., Zhu, F. P., and Bie, X. Y. (2008), "Experimental Research on the Influence of Particle Crushing on Direct Shear Strength of Sand", Journal of China University of Mining & Technology, Vol. 37, No. 3, May., pp. 291-294.