三角剪切模式(Trishear model)是用於解釋斷層與褶皺關係之運動學模式，在模式中影響褶皺形貌變化重要參數為斷層破裂距離和斷層滑移量之比值(P/S)。然而，三角剪切模式為運動學分析模式，因此P/S值之力學意義並不清楚。為了解P/S之力學意義，本研究以有限差分程式FLAC模擬斷層擴展褶皺(Fault-propagation fold)之地層變形過程，分析使用之彈性模式考慮斷層前緣初始深度、上覆地層彈性常數，而彈塑性模式考慮上覆地層與基盤間之摩擦性質對地層變形之影響。至於力學模型中P/S值乃利用位移-距離法(Displacement/Distance Method)加以計算，同時將變形反饋至三角剪切模式進行逆分析，以驗證位移-距離法於FLAC分析剖面之適用性。本研究採用位移-距離法獲得之結果充分反應累積剪應變增量之分佈，經將褶皺變形帶依變形特性分為三段後，本研究得以合理解釋並計算斷層擴展褶皺三角剪切模式中之P/S值。根據FLAC斷層擴展褶皺模擬及利用位移-距離法分析變形剖面之P/S值變化，結果顯示P/S值變化趨勢於斷層錯動過程中符合斷層成長模式(Fault-growth model)。除此之外，斷層前緣初始深度越深、上覆地層與基盤間之摩擦角越大則P/S值越大，其中尤以斷層前緣初始深度影響P/S值最為顯著，而上覆地層彈性常數對P/S值之影響則不明顯。

Trishear model is a kinematic model. It is used to simulate the geometry of fault-related fold. The ratio of fault-propagation to slip (P/S) is one of the important parameters of Trishear model which effects geometry of fold. However, the mechanical significance of P/S of Trishear model is unclear. This study used finite difference analysis software “FLAC” to simulate fault-propagation fold. The influence of initial depth of fault tip, elastic modulus of cover material and basement-cover contact strength on the P/S is investigated. In mechanical model, the P/S of deformed section is evaluated using Displacement-Distance Method. Backward analysis using Trishear model confirm that Displacement-Distance Method is suitable for determining the P/S value of deformed section import from FLAC analysis. P/S can be evaluated and explained reasonable by divide folded zone into three areas according to the deformed characteristics. The relation between the determined P/S and different slip of deformed section can be explained by Fault-growth model. Furthermore, P/S increase with increasing depth of fault tip and resistance to slip along basement-cover contact. On the other hand, the influence of elastic modulus on P/S is unobvious.

中文摘要 i
英文摘要 ii
誌 謝 iii
目 錄 iv
圖 目 錄 vii
表 目 錄 xii
第一章 緒論 1
1.1 研究動機與目的 1
1.2 研究方法 1
1.3 研究內容 4
第二章 文獻回顧 6
2.1 斷層擴展褶皺之運動學分析 7
2.2 斷層擴展褶皺運動學分析之數值模擬 11
2.3 力學分析法 13
2.3.1 以連續體力學為基礎之斷層擴展褶皺數值分析 13
2.3.2 以離散體力學為基礎之斷層擴展褶皺數值分析 15
第三章 研究方法與數值模型 18
3.1 FLAC程式之簡介及應用 18
3.1.1 FLAC程式概述 18
3.1.2 FLAC程式之運算程序 18
3.1.3 FLAC程式之理論架構 19
3.2 數值模型建立 22
3.3 位移-距離法(Displacement-Distance Method) 27
3.4 利用位移-距離法決定FLAC分析剖面之斷層前緣位置 28
第四章 結果與討論 35
4.1 位移-距離法適用性之驗證 35
4.2 利用累積塑性剪應變法與位移-距離法定義斷層前緣 38
4.3 上覆地層與基盤間摩擦角對P/S值之影響 39
4.4 斷層前緣初始深度對P/S值之影響 42
4.5 上覆地層彈性常數對P/S值之影響 44
4.6 斷層滑移量與P/S值之關係 46
第五章 結論與建議 49
5.1 結論 49
5.2 建議 50
參考文獻 51
附錄A 位移-距離法程式碼 53
附錄B FLAC程式碼 模擬上覆地層與基盤間之摩擦性質 57
附錄C FLAC程式碼 模擬斷層前緣初始深度(1公里) 62
附錄D FLAC程式碼 模擬上覆地層彈性常數 66

Allmendinger, R. W. (1998) Inverse and forward numerical modelong of trishear fault-propagation folds. Tectonics 17, 640-656.
Cardozo, N., Allmendinger, R. W. and Morgan, J. K. (2005) Influence of mechanical stratigraphy and initial stresss state on the formation of two fault propagateion folds. Journal of Structural Geology 27, 1954-1972.
Cardozo, N., Bhalla, K., Zehnder, A. T. and Allmendinger, R. W. (2003) Mechanical models of fault propagation folds and comparison to the trishear kinematic model. Journal of Structural Geology 25, 1-18.
Chen, W. S., Lee, K. J., Ponti, D. J., Prentice, C., Chen, Y. G., Chang, H. C., and Lee, Y. H. (2004) Paleoseismology of the Chelungpu Fault during the past 1900 years. Quaternary International 115-116, 167-176.
Chester, J. S. and Chester, F. M. (1990) Fault-propagation folds above thrusts with constant dip. Journal of Structural Geology 12, 903-910.
Cristallini, E. O. and Allmendinger, R. W. (2002) Backlimb trishear: a kinematic model for curved folds developed over angular fault bends. Journal of Structural Geology 24, 289-295.
Erslev, E. A. (1991) Trishear fault-propagation folding. Geology 19, 617-620.
Finch, E., Hardy, S. and Gawthorpe, R. (2003) Discrete element modeling of contractional fault-propagation folding above rigid basement fault blocks. Journal of Structural Geology 25, 515-528.
Gallup, W. B. (1951) Geology of Turner Valley oil and gas field,Alberta,Canada. Bull. Am. Ass. Petrol. Geol. 35, 797-821.
Hardy, S. and Ford, M. (1997) Numerical modeling of trishear fault propagateion folding. Tectonics 16 841-854.
Jamison, W. R. (1987) Geometric analysis of fold development in overthrust terrances. Journal of Structural Geology 9, 207-219.
Johnson, K. M. and Johnson, A. M. (2002) Mechanical models of trishear-like folds. Journal of Structural Geology 24, 277-287.
Kim, Y. S. and Sanderson, D. J. (2005) The relationship between displacement and length of faults:a review. Earth-Science Reviews 68, 317-334.
Suppe, J. and Medwedeff, D. A. (1984) Fault-propagation folding. Geological Society of America Abstracts with Programs 16, 670.
Suppe, J. (1985) Principles of structural geology, Prentice-Hall, Englewood Cliffs, New Jersey.
Suppe, J. and Medwedeff, D. A. (1990) Geometry and kinematics of fault-propagation folding. Eclogae Geologicae Helvetiae 83, 409-454.
Tavani, S., Storti, F. and Salvini, F. (2006) Double-edge fault-propagation folding:geometry and kinematics. Journal of Structural Geology 28, 19-35.
Watterson, J. (1986) Fault dimensions, displacement and growth. Pure and Applied Geophsics 124, 365-373.
Williams, G. and Chapman, T. (1983) Strains developed in the hangingwalls of thrust due to their slip/propagation rate: adislocation model. Journal of Structural Geology 5, 563-571.
王景平 (2002) 地表單斜褶皺與盲斷層之幾何關係探討，國立台灣大學土木工程學研究所碩士論文。
張正宜 (2000) 車籠埔斷層活動構造之數值模擬，國立中央大學應用地質研究所碩士論文。
許恆誌 (2004) 盲逆衝斷層活動時上覆土層內破裂擴展行為與變形區範圍之研究，國立台灣大學土木工程學研究所碩士論文。