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系統識別號 U0026-3008201611063500
論文名稱(中文) 載重效率對於未飽和土壤壓密過程之影響評估
論文名稱(英文) An Assessment of the Loading Efficiency on the Process of Consolidation in Unsaturated Soils
校院名稱 成功大學
系所名稱(中) 水利及海洋工程學系
系所名稱(英) Department of Hydraulics & Ocean Engineering
學年度 104
學期 2
出版年 105
研究生(中文) 鄧教弘
研究生(英文) Jiao-Hong Deng
電子信箱 lses60402@hotmail.com
學號 n86031065
學位類別 碩士
語文別 中文
論文頁數 73頁
口試委員 口試委員-賴建信
口試委員-陳主恵
口試委員-丁崇峯
口試委員-徐國錦
口試委員-李哲瑋
指導教授-羅偉誠
中文關鍵字 孔彈性壓密理論  非飽和土壤  載重效率  總沉陷量  震動載重 
英文關鍵字 Consolidation theory of poroelasticity  Unsaturated soils  Loading efficiency  Total settlement 
學科別分類
中文摘要 由於台灣水資源在乾濕季分佈的不平均,抽取地下水成為最快速且方便的供應選項,但因為早期國土保育的概念較為欠缺,導致過度抽取地下水造成地層下陷,近年來由於重大的交通建設發展,地表結構物的荷重對於下陷區域的影響也成為一項重要的議題。因此,若能將理論解析分析土壤壓密的量化結果應用在實際的工程現地上,對於日後解決工程問題應當有所幫助。在從事土壤壓密的研究通常以Terzaghi (1925)及Biot (1941)的研究為主要的依據,然而此兩理論在初始孔隙流體壓力的建立上有很大的差異,也就是載重效率(loading efficiency)的影響。前者(Terzaghi)假設載重一開始是全部由流體承受並不考慮載重效率,後者(Biot)假設載重一開始由流體承受的部份是由載重效率所決定。因此,本研究利用Lo et al. (2014)所發表的一維未飽和土壤孔彈性壓密理論進行研究,並且探討在考慮有無載重效率的存在對於孔隙流體壓力的消散及土壤的總沉陷量之影響,外部載重分為固定載重與震動載重。
本研究模擬的初始水飽和度分別為0.7、0.8及0.9,從數據結果可以看出,當載重作用初期(T=1min),土壤的無因次孔隙水壓在有考慮載重效率時比較小,但是當壓密時間為一天時,兩者模擬的結果卻非常接近,而土壤的總沉陷量在壓密初期也有明顯的不同,當壓密到達穩定時,模擬出來的結果卻是一樣的,以黏土為例(初始水飽和度=0.9,外部載重為固定載重,邊界條件為上排水邊界),當壓密時間為0.5小時,有無考慮載重效率時之土壤總沉陷量相差66.34%,而當壓密時間到達2.5小時,總沉陷量只相差4.44%。外部載重為震動載重時,壓密初期沒有考慮載重效率時之土壤的總沉量會出現負值,這並不符合物理現象,但是當壓密到達穩定時,有無考慮載重效率之結果卻是一樣的。因此,由本研究結果可知若要探討未飽和土壤初期壓密的影響,則必須考慮載重效率的作用。
英文摘要 Due to the uneven distribution of water resources during wet and dry seasons in Taiwan, the extraction of groundwater has become one of the most rapid and convenient supply options. In addition, the lack of a concept for national land conservation has led to overpumping of groundwater, thus causing land subsidence. In recent years, because of the development of the transport infrastructure, the impact of the loading of surface structures on land subsidence regions has become a crucial issue. The Taiwan High Speed Rail Corporation has been monitoring the vertical displacement of the railroad pier every year since 2003. The latest monitoring results show that land subsidence in Changhua and Yunlin counties is respectively around 3 to 5 centimeters every year, which threatens the safety of the high speed rail. Thus, it remains a necessity to develop a rational approach to solving these engineering problems based on theoretical analysis. To date, the most widely-used theories of consolidation are those of Terzaghi (1925) and Biot (1941). However, these two theories are different in many aspects, especially in terms of developing initial pore fluid pressure. In the current study, we apply the consolidation theory of poroelasticity developed by Lo et al. (2014) to illustrate the effect of loading efficiency on one-dimensional consolidation in unsaturated soils. Based on Lo et al. (2014), closed-form analytical solutions describing the excess pore air and water pressures along with the total settlement in response to time-invariant external loading under three boundary drainage conditions are formulated by employing the Laplace transform. In Terzaghi’s (1943) theory, at the instant the external loading is applied, it is assumed to be sustained entirely by pore fluid, while in Biot’s (1941) theory, the external loading is partially sustained by pore fluid according to loading efficiency.
As illustrated through the use of samples, three initial water saturations (i.e., 0.7, 0.8, and 0.9) with respect to various elapsed time periods (i.e., 1 min, 1 hr, and 1 day) are selected for (i.e., clay) soils. Our numerical results show that, in the early stage of consolidation (T=1 min), excess pore water pressure with loading efficiency is well represented and is less than that by ignoring loading efficiency. For a longer elapsed time (T=1 day), the differences between excess pore water pressures induced with or without loading efficiency included are quite small. We also demonstrate that the total settlement is significantly different between these situations in the early stage of consolidation. As the process of consolidation undergoes one day, the total settlement achieves the same magnitude with respect to these two situations. Thus, in the early stage of soil consolidation, if loading efficiency is not well represented, initial total settlement will be underestimated.
論文目次 中文摘要 I
英文摘要 II
致謝 XIV
目錄 XV
表目錄 XVII
圖目錄 XVIII
符號說明 XXII
第一張、緒論 1
1-1、研究動機與目的 1
1-2、文獻回顧 2
1-3、本文架構 7
1-4、流程圖 8
第二章、研究理論 9
2-1、孔彈性壓密理論方程式 9
2-2、線性應力-應變關係式 12
2-3、一維未飽和壓密理論 16
2-4、初始條件與邊界條件 17
2-5、解析解 21
第三章、數值模擬 32
3-1、保水曲線 32
3-2、水力傳導函數 32
第四章、結果與討論 34
4-1、在固定載重下探討有無載重效率時之無因次孔隙水壓及土壤沉陷的變化 35
4-2、在震動載重下探討有無載重效率時之無因次孔隙水壓及土壤沉陷的變化 36
第五章、結論與建議 68
5-1、結論 68
5-2、建議 69
參考文獻 70
參考文獻 1. Biot, M.A.,“General theory of three-dimensional consolidation,”J. Appl. Phys.,Vol 12, pp. 155-164, 1941.
2. Biot, M.A., and Willis, D.G.,“The elastic coefficients of the theory of consolidation,”J. Appl. Mech., Vol. 24, pp. 594-601, 1957.
3. Biot, M.A.,“Mechanics of deformation and acoustic propagation in porous media,” J. Appl. Phys., Vol. 33, No. 4, pp. 1482-1498, 1962.
4. Bishop, A.W.,“The effective stress principle,”Teknisk Ukeblad, Vol. 93, pp. 859-863, 1959.
5. Bishop, A.W., and Blight, G.E.,“Some aspects of effective stress in saturated and unsaturated soil,”Geotechnique, Vol. 13, No.3, pp. 177-197, 1963.
6. Bodvarsson, G., “Confined fluids as strain meters,” J . Geophys. Res.,75, 2711-2718, 1970.
7. Bredehoeft, J. D., H. It. Cooper, Jr., and I. S. Papadopulos, Inertial and storage effects in wellaquifer systems: an analog investigation, Water Resources Res., 2(4), 697-707, 1966.
8. Bredehoeft, j. D., Response of well-aquifer systems to earth tides, J. Geophys. Res., 72, 3075-3087, 1967.
9. Dale, R. H., Relationship of groundwater tides to ocean tides: A digital simulation model, Ph.D. dissertation, 150 pp., Univ. of Hawaii, Honolulu, 1974.
10. George, W. O., and F. E. Romberg, Tide producing forces and artesian pressures, Trans. Am. Geophys. Union, 32, 369-371, 1951.
11. Grablovitz, G., Sul fenomeno di marea osservato nelle miniere di Dun in Bohemia, Bull. Soc. Adriatica Sci. Naturali Trieste6, , 34, 1880
12. Gieske• A., On phase shifts and periodic well fluctuations, Geophys. J.R. Astron. Soc., 86, 789-799, 1986.
13. Hanson, J. M., Reservoir response to tidal and barometric effects, Geotherm. Resour. Counc. Trans. 4, 337-340, 1980.
14. Hsieh, P. A., J. D. Bredehoeft, and J. M. Farr, Estimation of aquifer transmissivity from phase analysis of earth-tide fluctuations of water levels in artesian wells, Water Resour. Res., 23, 1824-1832, 1987.
15. Hurley, M. T., Application of Biot's theory to sea-beds ediments, Ph.D. thesis, Univ. of Wales, Bangor, 1989.
16. Jacob, C.E.,“On the flow of water in an elastic artesian aquifer,”Eos. Trans. AGU, Vol. 21, pp. 574-586, 1940.
17. Johnson, A. G., R. L. Kovach, A. Nur, and J. R. Booker, Pore pressure changes during creep events on the San Andreas Fault, J. Geophys. Res., 78, 851-857, 1973
18. Jennings, J.E. B., and J. B. Burland, Limitations to the use of effective stresses in partly saturated soils, Geotechnique, vol. 12, no. 2, pp. 125-144,1962.
19. Klonne, F., Die periodischen schwankungen des wasserspigels in den inundieten kohlenschachten von Dux in der period von 8 April bis 15 September 1879, Sitzber. Kais. Akad. Wiss., 1880.
20. Lo, W.C., Sposito G., and Majer, E.,“Immiscible two-phase fluid flows in deformable porous media, Adv. Water Resour.,”Vol. 25, No. 8-12, pp. 1105-1117, 2002.
21. Lo, W.C., Sposito, G., and Majer, E.,“Wave propagation through elastic porous media containing two immiscible fluids,”Water Resour. Res., Vol. 41, W02025, 2005.
22. Lo, W.C., Yeh, C.L., and Tsai, C.T.,“Effect of soil texture on the propagation and attenuation of acoustic wave at unsaturated conditions,”J. Hydrology, Vol. 338, pp. 273-284, 2007.
23. Lo, W.C., Yeh, C.L., and Jan, C.D.,“Effect of soil texture and excitation frequency on the propagation and attenuation of acoustic wave at saturated conditions,”J Hydrology, Vol, 357, pp. 270-281, 2008.
24. Lo, W.C. , Sposito, G., and Huang, Y. H., “Modeling seismic stimulation: Enhanced non-aqueous fluid extraction from saturated porous media under pore-pressure pulsing at low frequencies”, J Appl Geophys, Vol. 78, pp. 77-84, 2012.
25. Lo, W.C., and Sposito, G.,“Acoustic waves in unsaturated soils,”Water Resour. Res., Vol. 49, No. 9, pp. 5674-5684, 2013.
26. Lo, W.C., Sposito, G., and Chu, H.,“Poroelastic theory of consolidation in unsaturated soils,”Vadose Zone J, Vol. 13, No. 5, 2014.
27. Lloret, A., and E. E. Alonso, Consolidation of unsaturated soils including swelling and collapse behavior, Geotechnique, vol. 30, no 4, 1980.
28. Lambe, T . W., and R. V. Whitman, Soil Mechanics, SI version,5 53 pp.,John Wiley, New York, 1979.
29. Melchior, P., A. Sterling, and A. Wery, Effets de dilatations cubiques due aux marees terrestres observes sous forme de variations de niveau dans un puits, a Basecles (Hainaut), Commun. Obs. Roy. Belgique, no. 224, 12 pp., 1964.
30. Marine, I. W., Water level fluctuations due to earth tides in a well pumping from slightly fractured crystalline rock, Water Resour. Res., 11, 165-173, 1975.
31. Morland, L. W., and E. C. Donaldson, Correlation of porosity and permeability of reservoirs with well oscillations induced by earth tides, Geophys. J. R. Astron. $oc., 79, 705-725, 1984.
32. Narasimhan,T . N., and B. Y. Kanehiro, A note on the meaning of storage coefficient, Water Resour. Res., 14(2), 423-429, 1980.
33. Narasimhan, T. N., B. Y. Kanehiro, and P. A. Witherspoon, Interpretation of earth tide response of three deep, confined aquifers, Geophys. Res., 89(B3), 1913-1924, 1984.
34. Oka, F.,T. Adachi, and Y. Okano, Two –dimensional consolidation analysis using an elasto-viscoplastic constitutive equation, International Journal for Numerical and Analytical Methods in Geomechanics, 10, 1-16,1986.
35. Robinson, T. W., Earth-tides shown by fluctuations of water-levels in wells in New Mexico and Iowa, Trans. Am. Geophys. Union, 20, 656-666, 1939.
36. Richardson, R. M., Tidal fluctuations of water level observed in wells in east Tennessee, Trans. Am. Geophys. Union, 37, 461-462, 1956
37. Robinson E. S., and R. T. Bell, Tides in confined well aquifer systems. d. Geophys. Res., 76(8), 1857-1869, 1971.
38. Rhoads, G. H. & Robinson, E. S., Determination of aquifer parameters from well tides, J. geophys. Res., 84, 6071-6082. 1979.
39. Rojstaczer, S., Intermediate period response of water levels in wells to strain: Sensitivity and noise level, J. Geophys. Res., in press, 1988.
40. Terzaghi, K., Erdbaumechanik auf Bodenphysikalischer, Deutichke, Vienna, 1925.
41. Terzaghi, K., Theoretical soil mechanics, John Wiley, New York, 1943.
42. van Genuchten, M. T.,“A closed-form equation for predicting the hydraulic conductivity of unsaturated soils,”Soil Sci. Soc. Am. J., Vol. 44, No. 5, pp. 892-898, 1980.
43. van der Kamp, G. and Gale, J.E.,“Theory of earth tide and barometric effects in porous media,”Wat. Resour. Res., Vol. 31, pp. 3103-3106, 1983.
44. Van der Kamp, G., Theory of Earth tide and barometric effects in a horizontal aquifer-aquitard system, Publ. R-844-7-E-89, 49 pp., Saskatchewan Res. Counc., Saskatoon, 1989.
45. Van der Kamp, G., and H. Maathuis, Annual fluctuations of groundwater levels as a result of loading by surface moisture, J. Hydrol.,1 27, 137-152, 1991.
46. Van der Kamp, G., Tidally induced fluid movement and tidal energy dissipation in subsea formations, paper presented at 39th Annual Pacific Northwest AGU Meeting, Victoria, B.C., Sept. 23-25, 1992.
47. Weeks,E . P., Barometric fluctuations in wells tapping deep unconfined aquifers, Water Resour. Res., 15, 1167-1176, 1979.
48. Wang, K., and E. E. Davis, Theory for the propagation of tidally induced pore pressure variations in layered subseafloor formations, J. Geophys. Res., 101(B5), 11,483–11,495.1996.
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