利用彎曲元件量測孔隙水壓激發階段剪力波速之演化

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陳賦舫(Fu-fang Chen) 查詢紙本館藏

畢業系所

土木工程學系

論文名稱

利用彎曲元件量測孔隙水壓激發階段剪力波速之演化
(Use of bender elements to investigate the evolution of shear wave velocity during undrained shearing in triaxial tests)

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摘要(中)

地震所引致反覆剪力，會使飽和砂土激發超額孔隙水壓，造成土體剪力強度改變。為深入瞭解砂土受剪後之力學行為，本研究利用放置於三軸室試體上、下蓋內的一對彎曲元件(bender elements)，藉元件壓電特性，於緩慢剪動飽和砂試體同時，在擾動極小的情況下量測傳遞經試體之剪力波波速(Vs)。掌握剪力波速的變化，即可由彈性波傳理論計算土體隨應力狀態改變而演化的重要動態參數最大剪力模數(Gmax)。
　　本研究首先將彎曲元件作適當的防水及絕緣措施，以利進行飽和砂的三軸壓密不排水試驗，並降低接收波形雜訊及電磁干擾。為瞭解彎曲元件的性能，先於等向壓密階段，測試不同激發波形及頻率對接收訊號之影響，以選擇最適用的激發波，並建立波傳時間判定準則。爾後以此準則計算三軸試驗各階段所量測之砂土剪力波速。
　　研究結果顯示，本研究配置下最適激發波為頻率12kHz至15kHz之單一週期正弦波；試體受到等向圍壓時，剪力波速與圍壓在雙對數座標下呈現斜直線分布，等向圍壓越高砂土剪力波速越高；試體剪動階段，藉超額孔隙水壓激發程度與剪力波速之關係，可看出波速不同於等向壓密階段只受等向圍壓的影響，試體受剪時，軸向壓縮會使剪力波速增高、軸向伸張則使剪力波速降低。另外，剪力波速與有效平均主應力的改變呈正相關，故利用回歸分析可得到以孔隙比與有效平均主應力為參數之剪力波速預測公式，預測與實測值接近且趨勢相似，僅在軸向伸張至主應力比小於0.5時實測值出現明顯低於預測值之情形。

摘要(英)

The cyclic shear stress induced by earthquakes would increase the excess pore water pressure and decrease the soil strength in a saturated sand deposit. For investigating the mechanism of sand during shearing, a pair of bender elements was mounted in both the cap and pedestal of the triaxial apparatus. Using the bender elements can measure the shear wave velocity while the saturated sand specimen was subjected to slow shearing. Therefore, the maximum shear modulus,Gmax, one of the key parameters for predicting dynamic behavior of soil, can be evaluated by the measured shear wave velocity (Vs) during the consolidated-undrained triaxial test at different stress paths.
Before the test, the bender elements were waterproofed, shielded, and grounded in order to work in the saturated sand specimens and to reduce electromagnetic interference of received signals. Besides, for knowing the properties of bender elements and determining the criterion of arrival time of the measured wave, three kinds of exciting waveforms and different ranges of exciting frequencies were examined at the consolidation stage in advance.
The test results showed that the most suitable transmitting signal was a single sine pulse with frequencies between 12 kHz to 15 kHz. The increase in the isotropic confining pressure increased the shear wave velocity. Nevertheless, during shearing, the shear wave velocity was affected by not only the effective confining pressure but also the stress state on the soil specimen. By the regression analysis, an empirical equation was proposed to predict the shear wave velocity based on the void ratio and the effective mean stress of soil specimen. The predicted values were closed to the measured ones when the stress ratio was greater than 0.5 and less than 3.

關鍵字(中)

★ 三軸壓密不排水試驗
★ 彎曲元件
★ 剪力波速
★ 超額孔隙水壓

關鍵字(英)

★ shear wave velocity
★ bender elements
★ consolidated-undrained triaxial test
★ excess pore water pressure

論文目次

摘要　i
ABSTRACT　ii
致謝　iii
目錄　v
表目錄　viii
圖目錄　ix
符號說明　xiv
第1章　緒論　1
1-1研究動機　1
1-2研究方法及流程　1
1-3論文架構　2
第2章　文獻回顧　5
2-1量測土壤剪力波波速的方法　5
2-1-1移動時間法　5
2-1-2共振柱試驗　6
2-2利用彎曲元件量測剪力波波速之發展演進　7
2-2-1新波速感測器的出現　7
2-2-2彎曲元件量測發展初期　9
2-2-3彎曲元件法量測準確性的提升　10
2-2-4彎曲元件之應用　17
2-3影響剪力波波速之因子　18
2-4最大剪力模數　19
第3章　試驗規劃、儀器設備及試驗方法　39
3-1試驗規劃　39
3-2試驗土樣說明　40
3-3試驗儀器設備　41
3-3-1三軸試驗設備　41
3-3-2剪力波波速量測設備　52
3-3-3彎曲元件防水及降低雜訊加工與固定於試體端座之施作　56
3-4試驗方法　58
3-4-1試驗前的準備工作　58
3-4-2試體製作及飽和　60
3-4-3壓密階段(試驗計畫Ⅰ、試驗計畫Ⅱ)　63
3-4-4剪動階段(試驗計畫Ⅲ、試驗計畫Ⅳ)　64
3-5試驗編號說明　65
3-6小結　66
第4章　試驗結果與分析　97
4-1激發波的選擇　97
4-1-1激發波種類　97
4-1-2試驗方法　98
4-1-3接收波　99
4-1-4接收波到達時間判定　107
4-1-5不同激發頻率對計算剪力波波速的準確性　110
4-2等向壓密階段有效圍壓與孔隙比及剪力波波速之關係　111
4-2-1等向壓密過程　111
4-2-2孔隙比與有效圍壓的關係　112
4-2-3剪力波波速與有效圍壓的關係　112
4-3三軸壓密不排水試驗剪動階段的剪力波波速變化　114
4-3-1試驗方法　114
4-3-2三軸壓密不排水試驗結果　116
4-3-3剪動階段的剪力波波速變化　122
4-4剪力波波速量測值與預測值之比較　128
4-4-1以超額孔隙水壓比預測剪力波波速　128
4-4-2以有效平均主應力預測剪力波波速　130
4-5小結　132
第5章　結論與建議　203
5-1結論　203
5-2建議　204
參考文獻　207

參考文獻

[1]Abbiss, C.P., "Shear wave measurement of the elasticity of ground," Geotechnique, Vol.31, No.1, pp.91-104 (1981).
[2]Arulnathan, R., Boulanger, R.W., and Riemer, M.F. "Analysis of bender element tests," Geotechnical Testing Journal, Vol.21, No.2, pp.120-131 (1998).
[3]Baxter, C.D.P., Bradshaw, A.S., Green, R.A., and Wang, J.-H., "Correlation between cyclic resistance and shear-wave velocity for Providence silts," Journal of Geotechnical and Geoenvironmantal Engineering, Vol.134, No.1, pp.37-46 (2008).
[4]Brignoli, E., and Gotti, M., "Measurement of shear waves in laboratory specimens by means of piezoelectric transducers," Geotechnical Testing Journal, Vol.19, No.4, pp.384-397 (1996).
[5]Carlson, A.B., Communication Systems—An Introduction to Signals and Noise in Electrical Communication, McGraw-Hill, New York, (1986).
[6]Das, B.M., Principles of geotechnical engineering, 5th ed., Brooks Cole, U.S.A., (2001).
[7]Das, B.M., Principles of soil dynamics, Pws-Kent, U.S.A., (1992).
[8]Dyvik, R., and Madshus, C., "Lab measurements of Gmax using bender elements," Advances in the Art of Testing Soils Under Cyclic Conditions, ASCE, New York, pp.186-196 (1985).
[9]Hall, J.R., and Richart Jr, F.E., "Dissipation of elastic wave energy in granular soils," Journal of the Soil Mechanics and Foundations Division, ASCE, Vol.89 , No.SM6, pp.27-55 (1963).
[10]Hardin, B.O., and Black, W.L., "Vibration modulus of normally consolidated clay," Journal of the Soil Mechanics and Foundations Division, Vol.94 , No.SM2, pp.353-369 (1968).
[11]Hardin, B.O., and Richart Jr, F.E., "Elastic wave velocities in granular soils," Journal of the Soil Mechanics and Foundations Division, Vol.89 , No.SM1, pp.33-65 (1963).
[12]Huang, Y.-T., Huang, A.-B., Kuo, Y.-C., and Tsai, M.-D., "A laboratory study on the undrained strength of a silty sand from central western Taiwan," Soil Dynamics and Earthquake Engineering, Vol.24, pp.733-743 (2004).
[13]Ishibashi, I., Chen. Y.-C., and Jenkins, J.T. "Dynamic shear modulus and fabric: part II, stress reversal," Geotechnique, Vol.38, No.1, pp.33-37 (1988).
[14]Jovicic, V., Coop, M.R., and Simic, M., "Objective criteria for determining Gmax from bender element tests," Geotechnique. Vol.46, No.2, pp.357-362 (1996).
[15]Lambe, T.W., and Whitman, R.V., Soil Mechanics, U.S.A., (1928).
[16]Lawrence, F.V., "Propagation of ultrasonic waves through sand," Research report R63-08, Massachusetts Institute of Technology, Boston, (1963).
[17]Lawrence, F.V., "Ultrasonic shear wave velocity in sand and clay," Research report R65-05. Massachusetts Institute of Technology, Boston, (1965).
[18]Lee, C.-J., and Huang, H.Y., "Wave velocities and their relation to fabric evolution during the shearing of sands," Soil Dynamics and Earthquake Engineering, Vol.27, No.1, pp.1-13 (2007).
[19]Lee, J.-S., and Santamarina, J.C., "Bender elements: Performance and signal interpretation," Journal of Geotechnical and Geoenvironmantal Engineering, Vol.131, No.9, pp.1063-1070 (2005).
[20]Leong, E.C., Yeo, S.H., and Rahardjo, H., "Measuring shear wave velocity using bender elements," Geotechnical Testing Journal, Vol.28, No.5, pp.488-498 (2005).
[21]Mancuso, C., "Numerical analysis of in situ S-wave measurements," Proceedings of the 12th International Conference on Soil Mechanics and Foundation Engineering, Vol.1, Rio de Janeiro, Brazil, pp.277-280 (1989).
[22]Miura, S. and Toki, S., "A sample preparation method and its effect on static and cyclic deformation-strength properties of sand," Soils and Foundations, Vol.22, No.1, pp.91-77 (1982).
[23]NG, C.W.W., and Yung, S.Y., "Determination of the anisotropic shear stiffness of an unsaturated decomposed soil," Geotechnique, Vol. 58, No.1, pp.23-35 (2008).
[24]Schultheiss, P.J., "Simultaneous measurements of P & S wave velocities during conventional laboratory soil testing procedures," Marine Geotechnology, Vol.4, No.4, pp.343-367 (1981).
[25]Sharifipour, M., Dano, C., and Hicher, P.-Y., "Wave velocities in assemblies of glass beads using bender-extender elements," the 17th ASCE Engineering Mechanics Conference, University of Delaware, Newark, DE, (2004).
[26]Shirley, D.J., "An improved shear wave transducer," Journal of the Acoustical Society of America, Vol. 63, No.5, pp.1643-1645 (1978).
[27]Shirley, D.J., and Hampton, L.D., "Shear wave measurements in laboratory sediments," Journal of the Acoustical Society of America, Vol.63, No.2, pp.607-613 (1978).
[28]Thomann, T.G., and Hryciw, R.D., "Laboratory measurement of small strain shear modulus under K0 conditions," Geotechnical Testing Journal, Vol.13, No.2, pp.97-105 (1990).
[29]Viggiani, G., “Small strain stiffness of fine grained soils,” PhD thesis. City University, London, (1992).
[30]Viggiani, G., and Atkinson, J.H., "Interpretation of bender element tests," Geotechnique, Vol.45, No.1, pp.149-154 (1995).
[31]Yamashita, S., Kawaguchi, T., Nakata, Y., Mikami, T., Fujiwara, T., and Shibuya, T., "Interpretation of international parallel test on the measurement of Gmax using bender elements," Soils and Foundations, Vol.49, No.4, pp.631-650 (2009).
[32]Yu, P., and Richart Jr., F.E. "Stress ratio effects on shear modulus of dry sands," Journal of Geotechnical Engineering, Vol.110, No.3, pp.331-345 (1984).
[33]Zhou, Y.-G., and Chen, Y.-M.,"Influence of seismic cyclic loading history on small strain shear modulus of saturated sands," Soil Dynamics and Earthquake Engineering, Vol.25, No.5, pp.341–353 (2005).
[34]林保延，「利用彎曲元件試驗推估砂土動態性質之探討」，碩士論文，國立台灣科技大學營建工程研究所，台北 (2005)。
[35]林靜怡，「細粒料對粉土細砂小應變勁度之影響」，碩士論文，國立交通大學土木工程研究所，新竹 (2003)。
[36]林友勝，「不等向壓密飽和夯實土壤之動態變形行為」碩士論文，國立中央大學土木工程研究所，中壢 (2008)。
[37]郭毓真，「細粒料含量對麥寮砂動態行為之影響」，碩士論文，國立交通大學土木工程研究所，新竹 (2004)。
[38]鄺柏軒，「利用動態離心模型試驗模擬砂土層之剪應力與剪應變關係」，碩士論文，國立中央大學土木工程研究所，中壢 (2010)。
[39]高明宏，「台北沈泥質粘土小應變之不排水勁度模數的量測」碩士論文，國立台灣科技大學營建工程研究所，台北 (2001)。
[40]黃香燕，「利用壓電晶片量測不同應力條件下之砂土傳波速度」，碩士論文，國立中央大學土木工程研究所，中壢 (1998)。
[41]黃耀道，「台灣中西部粉土質砂土液化行為分析」博士論文，國立交通大學土木工程研究所，新竹 (2007)。
[42]邱建銘，「以剪力波速評估員林地區液化及其地層動態反應研究」，碩士論文，國立台灣大學土木工程研究所，台北 (2001)。
[43]闕慎佑，「K0狀態下低塑性粉質砂土原樣與重模試驗之液化行為與動態特性比較」，國立暨南國際大學土木工程研究所，南投 (2010)。
[44]陳志安，「不同程度影響因素對不同緊密度砂土液化特性之研究」，碩士論文，國立台灣大學土木工程研究所，台北 (1990)。
[45]陳瑞禾，「現地試驗評估粘土初始剪力模數之初步研究」，碩士論文，國立台灣大學土木工程研究所，台北 (1997)。
[46]蔡榮燦，「砂土組構及傳波速度」，碩士論文，國立中央大學土木工程研究所，中壢 (1999)。
[47]吳松旺，「前期反復荷重對砂土液化行為之影響」碩士論文，國立台灣科技大學營建工程研究所，台北 (2006)。
[48]王崇儒，「利用壓電彎曲元件探查離心砂土模型剪力波波速剖面及其工程上的應用」，國立中央大學土木工程研究所，中壢(2010)。

指導教授

李崇正(Chung-jung Lee)

審核日期

2011-1-19

推文